/diy/ - Do It Yourself

I just got this working yesterday.

I'm going to be making a PCB for this in OrCAD in the upcoming week hopefully.

Pretty hype.

>>794223
Oh, that's cool.

I'm making a pleb tier line following robot.

>>794221
post more kawaii pcbs
anime is fucking gay but that is just too cute.

>>794223

what refresh period ?? and the name of those vacum tubes ?

Are u usinf those standart ic for digital 7 pins displayers?

I'm trying to work with electrostatic stuff but I really don't want these to break down. I've purchased the wristband and a conductive mat so far but I'm not sure what to use for ground. Is any large metallic object okay? And once I get it, I can touch my parts as much as I want?

>>794303
also interested. is touching a medium-size (~ 1 gallon) solid copper pot for a few seconds sufficient?

>>794301

IN-14 tubes. New old stock from Ukraine.

I'm using the k155id1 chip designed specifically for Nixie tubes. The k155id1 chip is the soviet equivalent to the US's 74141 driver chip.

>>794320
Is it supposed to be one chip per tube?

>>794303
>>794306
Touching a conductive thing is better than nothing, but isolated objects don't have a good path to ground and you'll just reduce your ESD potential as opposed to eliminating it. Assuming your house wiring is properly grounded (which is not guaranteed) the best connection to make is to that ground, or a metal appliance case. A water pipe will also work.

How exactly am I supposed to program a microchip? I've seen a board where you connect the chip and the debugger into but I haven't seen an schematic that shows how to remake it.

>What software should I use to print circuits

>Circuit Wizard
>ExpressPCB
>EAGLE

Is there a reason KiCAD is left off this list?

pros / cons to a career in electronics?
I like to work with my hands

>>794223
>5 is an upside-down 2

Slavs may be genetically predisposed to cut corners.

>>794223
where the hell is your voltage regulator?

>>794428
It's a wide field. Apart from prototyping, EEs don't do much by hand. From a career perspective, analog or RF design are probably the safest bets. More general work is slowly but surely transitioning to the far east.

Is there anything similar to this? I already know the basics and I want to start trying to make my own circuits.

>>794487

It's off the screen to the right. Separate board I bought.

My dad has a copy of this book(This version, not the second edition). I know it's dated, but is it worth using, or are there things it teaches that are wrong?

>>794557
Not that I know of, but we could make one.

>>794562
Can you post a simple schematic of how you wired up everything?

>>794557
Yeah, let's do this.

We'll need someone that's decent with image editing software to produce a nice looking list.

And for the rest of us, post project ideas, we'll need to gather 100.

I'll start:
>Linear PSU
>Switching PSU
>Voice Changer
>Clapping light switch
>LC Meter
>VU Meter
>Lightshow
>Breathalyzer
>Digital clock, Segment Display
>Digital clock, LED Matrix
>Nixie clock

>>794223
>>794484
I just noticed that. Damn that is ugly.

>>794591
Inverted pendulum
Voltage controlled oscillator
Tube audio amplifier
Transistor audio amplifier
Battery charger
Linear current supply
Switching current supply
Stepper driver
Line following robot
Maze solving robot
LED Tachometer
Music player

Got a flash from an old camera. How can i make it work and 2. is there anything i can use it for

I just noticed that my jack for a plug has these big leads with holes at the end that won't fit into the breadboard. How do I connect this to a breadboard?

>>794629
STUN GUUN

>>794648
Explain....

>>794629
Power supply for nixie tubes.

>>794484
>>794592
they made proper fives as well.

i like the upside down 2 though, adds character.

>>794221
>>794398

Might want to add 123d.circuits.io to the software print/Sim list. I'm using it because it's far better than the Linux equivalent. So I'll probably be sticking to online cad.

I've just started using it so I can't really compare it to anything as this is my first real project that requires a schematic not written by hand.

Current limitation: in my circuit, it contains 1 arduino micro and one atmega3** (uno equivalent). They both can power/control the same sub circuits (but obviously only one is supposed to be used). I want the option of being able to swap them out, so I want to just use ic sockets in the schematic but can't seem to find a symbol for it, and making one without specs is kinda hard.

Anyone have an idea on how I could proceed with making this schematic?

>>794591
Add some 555 circuits in the mix. We just need someone to make a nice rolling list like the /g/ one

>>794221
I recently bought two of these:
http://www.ebay.com/itm/-/271637502864?roken=cUgayN&soutkn=j26pEJ
I either damaged one or it was damaged on arrival. Regardless, battery pack shorted out as I was installing into the case. The board powers up, but frankly I can't trust it anymore to be safe to use.
My question is, can I add 8 cells in parallel to a single one of these boards and discard the original housing?
Aside from a couple of marmosets and a single unmarked chip it has a DW01A chip. can it handle charging 8*2.3Ah bank?

ok so /ohm/ so here's what i'm working on. I have this good friend who may suffer from mild auditory hallucinations and I'm kind of an asshole so what i've done bought ISD1820 audio recording IC thing holds 10 sec of audio fair quality and has built in amp. So i'm waiting on some vibration sensor units from fleabay. and what i'm going to do is program a pic so that if the sensors vibrate at a certain threshold this will set up a timer that will randomly select a time period from 30 secs to 3 minutes after which it will trigger the chip. The audio track is non selectable but after waiting enough time for the desired segment to play (also randomly selected from three creepy sound clips. mr food's oh it's so good, crying baby, random segment from baptist preacher) that PIC will also turn on the speaker.

I'm using a small laptop speaker and powering the whole unit from 3 button cells. My plan is to wait to i'm at his house and sneak into his room take his pillow out of case cut open his pillow and insert the device into the cotton tape it back up with fabric tape slip the cover back over it. The whole thing runs in low power mode after not being triggered for awhile and draws only pico amps so it will last awhile.

i think it be brutty gud'

I suck and marked up this board a lot because i have a really shit soldering iron, is this board completely fucked or is it just surface damage

>>794869
looks alright. It's one of those old boards isn't it? Just be patient, if you can change the tip for something larger with greater thermal capacity you should. Be patient and use either a solder sucker or better yet solder wick.

>>794869
the only purpose of the PCB is to move electricity from one point to another. as long as the traces are uncut and unshorted, the aesthetics count for nothing.

>>794881
Yeah its an older board, late 70's calculator but it isnt calculating right, i checked the parts and all the capacitors were bad so i was going to replace those and then trouble shoot some more. All i have right now is a pointed tip because my broader tip broke. I do have a solder sucker though but its rubbish as well.

>>794895
If I could recommend you a soldering iron, get the Weller WES51. I've had it for a few years and it's served me very well. Made soldering a ton easier.

>>794895
then wait for the wider tip. You probably can get it done with your current iron but you;re not heating it right.

>>794586

I can; it's pretty simple though. I'll get around to it tomorrow maybe. Maybe this will suffice for now:

clock, data, strobe to a shift register from arduino or any other microcontroller,
4 outputs from shift register to the inputs of one of the nixie driver chips, the other 4 to the other chip.
Hook up the nixies to the drivers appropriately. I put a ~5k 1W resistor from the HV to each nixie, helped to keep from accidentally frying a shift register.

I Designed my first PCB! I hope it's G. It is a Teensy to +-15V DAC board for modular synthesizers or whatever. MIDI input & USB-MIDI

I call it TAC

>>794932
Pics?

>>794932
oops img i forgot

>>794935
also the skim, but its pretty straight forward if you understand this stuff. What i don't understand is Analog/Digital isolation. I have a separate 5V reg for the analog DAC, but i don't have an analog ground. Also i hope my grounds are not to long and inductive. i have been sprinkling 100nf caps everywhere, mimicking other synth module designs. I have been trying to fit it on a 5x10cm board, single sided, min- 10mil spacing so that its eazy for all kinds of manufacturing methods people use.

>>794939
You should do a ground fill on the top side, probably. As long as you're not sending digital signals to the right side of the board (past the DAC), you're likely ok.

Hello, I don't want to make a new thread for this, so I'll post it here. I want to do a active band pass filter. The input will be audio from an ipod (about 0,4 V) and I need to bring it up to 3.3 V. Fair enough, I go on a website which calculate resistors value I need for a Bessel filter. Then, I try that on
https://www.dcaclab.com/fr/lab?from_main_page=true
which is a simple app to simulate circuit (I can't understand other circuit simulators) but after I made my circuit, when I probe with the oscilloscope the output is complete garbage. Sorry if this is due to a stupid noobish mistake.

>>794951
and here is my circuit

>>794951
I assume "garbage" means oscillation. Too much gain + component tolerances.
Use a separate filter and amplifier and reduce Q.

>>794959
Well the signal isn't amplified at all at the output when you look at this pic.
>>794955
Ok I'll try that

>>794966
Even when working perfectly, it's a very narrowband filter. It'll attenuate everything that's outside its narrow passband. Use AC analysis, if you're playing with simulators.
It also needs a bipolar power supply to work in real world.

How to prevent darkening of tips?
What are the do's and donts?
Thanks :^)

>>795016

heat + oxygen gives you oxidation, no way around that. removing oxygen is hard, so removing heat is one way to do it. you can use some kind of movement detector to turn off the iron if not used for 3 minutes. or just use lower wattage irons. another way is to keep the tip caked in solder, so no oxygen gets to the tip. another way is to use quality steel tips like the $6 Weller ones. they come in many sizes, but if you cant find one that fits, you can grind it down.

>>795016
Tin your tips anon.

>>794951

I wouldnt trust a simulator that spells Oscilloscope as Osiliscope.

anyway, we cant see what the frequency of the signal generator is, so the output could be perfectly normal if you're far away from 100Hz. and BTW, the value of R3 is 34 ohms, so the signal is strongly attenuated before the filter, then amplified by the op-amp, so you should get about 3Vrms at 100Hz, but only 30mVrms at 300Hz.

>>795016
Nice thread

>>794995
>>795034
The generating signal was 100Hz so It should be 3Vrms indeed. But yhea I think this simulator is buggy. I made this schematic to be more clear, could you tell me if this will work ? I want to output 5v when audio comming from 3.5 mm jack has a certain frequency (here between 20 and 50 Hz).

>>794389

If you use a SPI programmer like AVR mkII you just connect the six pins of the programmer (look at the datasheet) to the equivalent lines on your board. The VCC, GND and RESET pins are self explanatory. The MOSI (master out slave in), MISO (master in slave out) and SCK pins will be at different places depending on which microcontroller you use.

>>795050
This is the first time I've seen two legs of transistor at the end of circuit. There's something wrong with it. I can sense it.

>>795054

>>795054
>>795055
Oups. I want the led to be on when the audio frequency is between 20 and 50 hz

>>795052
I'm trying to work with PIC and I kind of understand. However I always see other components on the board. What are some essentials needed?

>>795097
Well, you'll need an ICSP header to connect to the programmer, a resistor and cap to keep the memory clear line disabled when you're not programming it, a voltage regulator if your supply voltage is above the rated chip voltage, possibly a crystal if you want to run at a different or more precise frequency that the clock generator on the chip can do.

Let's say I've bought one of these and got it working: http://www.ebay.com/itm/361127289318?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
1. Does this give me cancer?
2. Does this give me eye damage?
3. Is there any way to know how much goes through for real?
4. Can I use this for a simple tesla coil?

The wire ends start shining and the device makes a high pitched noise if I keep them apart for more then 2.5 cm, ocasionally sparking(or does it arc?)

>>795105
That helps thank you. Are voltage regulators electrostatic sensative? Is it alright to just put it back into the bag after my usage?

>>794685
Assuming you're using DIP packages, just use the DIP footprint for the socket.

>>795112
Guys please, I'm starting to hear a hissing/ringing sound in my ears now.
What the fuck
I've also found it radiates UV light, so definitely eye damage/welders eye when you look into it.
What kind of precautions should I take handling this thing?

>>794898
I'll look into that one, i desperately need a new one

>>795175
I have no clue what the fuck that even is. Ebay for some reason is fucked on my phone's browser.
>>795176
You could use one, but you don't need it. It's about keeping your tip clean and tinned, and making the appropriate solder heat bridge where needed.

>>795177
Spark gap, claiming to be a good 700kV.
What should I do for safety and can I actually get shocked without damage? I've read about nerve damage from high voltage before but I might be wrong. It only sucks in around 2 amps from the input at 1.8 volts or something so I figured it's really low amps at the output.

>>795178
did you need it for something or did you just buy it because lol money?

>>795210
lol money and because i just wanted one
Be honest, you wouldn't really belong here if the only reason was "I need it"
That's kind of boring.
And I figured it's a nice way of triggering my potato launcher

>>795177
>>795028
On the subject of soldering (which i'm completely new to) i saw a video review of a cheapass soldering iron and the dude in the video ran a voltmeter over the box which the iron was connected to. When he ran it over the box the voltmeter spiked and he said that's a bad thing, but didn't say why. Does it mean there's a problem with the wiring or something?

>>795236
It means that the soldering iron is positively charged. It could cause current to flow to whatever you're soldering if it's grounded.
And seeing as power from the outlet is 100-230 Vac that's not really something you want.

>>795237
So does that mean if you were soldering a circuit board you could accidentally fry it? Try to explain it as though i'm a child, i really know absolutely nothing about this stuff

>>795240
It means exactly that.
Don't go cheap on a soldering iron, it'll only cost you more in the long run.
It's one of the most used tools in electronics.

>>795243
>don't go cheap
In that respect, i see soldering irons named "high heat capacity". Does that mean they can heat to a really high temperature?

>>795245
no.
irons power is how quickly it heats up
heat capacity is how much heat it can store, when you touch a component the heat in the iron is shared with the component, the iron cools down.
as the component size increases you need an iron with a higher heat capacity because unless the power is really high (or regulated properly) it won't be able to replace the heat lost to the component fast enough.

>>795249
Gotcha. Is lead free solder worth always using or are there downsides to it?

>>795253
Go leaded, 60/40 errytime.

Lead free is asking for trouble in the long run, and recommend not using unless your program requires it (bullshit safety standards; dangerous stuff gets the job done).

>>795253
>>795253
if you are just starting out you can't go wrong with a nice (lead) 60/40 rosin core. wash your hands when you are done is the usual advice and don't breathe in the fumes no matter how good they smell.
lead free gets a lot of hate and while it shouldn't ruin your day there is just something odd about it, just odd to work with but maybe that's just me.
theres something about a 63/37 mix or something like that giving a better working temperature but i can never find it in stock anywhere.

>>795257
>>795259
Recommended masks for soldering? (if at all) I'm not gonna be able to do it for a while either way because i live in a flat with no workshop area that'd be suitable.

>>795259
Ohp, forgot to specify rosin core, good catch.

Yeah, a lot of people are hot for 63/37. Try it out if you can.

In a nutshell, lead free has poor tolerances for extended periods of hot/cold cycles, and will become brittle and cause intermittent connections after some time.

>>795263
Masks? Oh, you probably meant eye protection.

Safety glasses are what you should wear. I've had splashes on my glasses now and then which could have blinded me, and know personally someone who was blinded in one eye by molten solder.

Relatively good ventilation is also preferred.

>>795268
Eye protection and for breathing. I know lead doesn't vaporise at the temperatures you solder at, but is it still worth getting a filtered breathing mask of some form?

>>795270
Yeah, you're on point. The fumes are the rosin flux burning off, not the lead.

What you don't want to do is touch your face or anything which could cause you to later ingest the lead.

No need for a breathing mask, just leave a door open and take a walk every two hours or so.

>>795271
I think i might do a soldering course when i've got the money. Any good books/websites you'd recommend for a newbie?

>>795284
Just start soldering shit together. Practice is everything.

>>795285
Fair enough. Anything good and cheap in particular to practice on?

>>795286
Start with simple wires.
See how the solder flows and what it takes to actually attach to shit.
You can't explain that stuff in words, you just have to try it.

>>794629
A small EMP generator. Hardest part is the coil, and making sure you don't flash weld your switch or button.

>>795286
cheap is just find some wire, solder a few bits together to practice

you can get kits, not necessarily cheap but good practice and some can be fun.
http://www.velleman.co.uk/contents/en-uk/d2_kits.html

>>795290
>>795292
Thanks guys. Currently doing a degree in Mathematics and Physics but theoretical gets boring sometimes aha

On-line tutorials:
https://learn.sparkfun.com/tutorials/how-to-solder---through-hole-soldering

https://learn.adafruit.com/collins-lab-soldering

>>795286
As the other anon said, tinning wires.

That's how I got my start, for audio applications.

Get some cheap chinese protoboard from ebay and practice making proper joints. Something like pic related. Solder in trimmed-off resistor leads to simulate real components if you like.

>>795298
Forgot pic.

>>795295
Yeah, it's a shame most schools don't require any real applied work.

Great to hear you're personally invested, the future is bright for people like you!

>>795304
Thanks man.
I'm looking to design weapons of all shapes and sizes for a private company, and while they recommend a Mathematics and Physics degree i feel i need to get some hands on experience too.

>>795237
>>795240
static charge buildup. Some components are far more delicate than others when it comes to static discharge. The soldering iron is definitely a factor; but considering this guy isn't using a wristband or a dissipative mat; no real point in concerning yourself with it.
>>795249
High heat capacity means that they won't lose heat at the tip easily, esentially; they can transfer more of the 'stored' heat in their mass. More so than the iron, what affects the most is the tip you're using.
>>795253
Unleaded can be avoided unless you're a manufacturer, teacher, or will have kids in contact with whatever you solder. It's still good to know how it behaves, but since you're a begginer and if you don't meet any of the above exceptions, go unleaded. The diameter is also important: .032" or lower works best, you can easily control how much you feed. If you're going shopping, it might be best for you to pick up some solder flux (flux pens are popular, never used on myself), a solder sucker, and some solder wick. If you're buying a new iron, might as well get some various tips.
>>795263
Work near a window, or you can modify a pc fan to blow flux fumes away/suck them into a filter.
>>795284
Save up that money and buy boards, components 'n shit. Youtube has, I kid you not, all the information you could possibly need. The catch is sorting through all the senseless shit. There a good old school tutorial that kept getting posted around here, I'll come back if I find it later.

>>795323
I forgot to mention pregnant women.

>>795323
What make good tips? Are there good brands/materials to buy/any to avoid?

>notice computer science is getting easy and more approachable
>disgusted
>look into EE
>same thing happening there

Why must time move forward?

>>795354
It's, like, inevitable maaaaan

Hey, bit of a newbie here. I'm using a PIC microcontroller (PIC24f16KL402) and trying to get an LCD screen to work with it (the 8x2 3.3v sparkfun one). I've already tried google, the code I'm using is from a tutorial but it doesn't work (yes I changed the pins and the delays).

LCD is connected like so:

Vss, Contrast Adjust, R/W Enable, LED-: Ground
Vdd, LED+: 3.5V
RS: RA0
Enable: RA1
DB0~DB7: RB0~RB7

I'm using this code: https://www.mediafire.com/?ue14ar5af33ag3h , MPLAB X and the xc16 compiler.

I just can't, for the life of me, get it to display anything. The screen flashes black boxes on Initilize_LCD() and that's it.

Someone here has to have experience with this, right? What am I doing wrong? I follow the tutorials closely and read the datasheets for the LCD screen but no results.

>>795378
Instead of ""werks"
try sending only one letter at a time.

The code doesn't seem to account for multiple letters.

If that doesn't work try replace
>WriteString_LCD("werks");
with
>WriteData_LCD(0x41);

In your main function

>>794611
>Maze solving robot
wouldnt this be identical to the line following robot? Follow one wall of any maze and you will eventually solve it.

>>795387
That didn't work, but thanks anyway. I can find someone irl to work on it with me, just wanted to see if I was missing that one little thing that prevents it from working...

>>795332
found the videos.
https://www.youtube.com/watch?v=vIT4ra6Mo0s
watch these lessons at your leisure. You don't have to sit through that 1970's buzzing vhs audio, but it does go into pretty much everything for a beginner.

>>795398
Simple wall following only works if all walls are connected together. If the goal is next to a detached wall the robot will repeat the same path forever instead of reaching it.

>>795461
How important is the flux needed? Unfortunately, Toronto has a sad lack of electrical equipment sources and I need to get most of my stuff of amazon.ca or else pay +20USD for shipping. Would something like this be okay for 60/40 solder rosin core?
www.amazon.ca/MG-Chemicals-Corrosive-Conductive-Residue/dp/B0080X79HG/ref=pd_cp_ce_0

>>795497
You don't really need flux for most work, the rosin core is enough.

Flux really comes in handy when you're working with larger copper surfaces or SMD.

>>795497
From a glance that should be good. Flux is so inexpensive there's no reason not to always have at least a flux pen handy. When you notice you're having problems getting the solder flowing, use some flux and you'll see why it's recommended.

>>794762
Alternatively:
Project -1: 100-sided electronic die.

THEN: projects 00-99, as rolled by the die.

>>795497
have you tried ebay as well? Often stuff is cheaper on ebay.

>>795354
How is EE getting more approachable?

>>795612
Ebay has this global shipping policy where we Canadians need to pay import taxes and almost every american seller uses it even though, in the past years I used to buy from eBay, I never had to pay the import taxes. So we'll be paying for the shipping ad well as these taxes which will often go over half or even the full price of the original object.

>>795658
Very fucking interesting. Michigan bro here. If for whatever reason you ever find yourself across the ambassador bridge with an hour and $100 USD to spare, go to a store called microcenter. Their selection, according to my father, is like old school radioshack albeit with less IC's. That definitely sucks, for whatever reason I was always under the impression that Canada had more relaxed import laws, considering all the skylines and other jap imports up there.

I'm surprised toronto doesn't have a major electronics component retailer. Look around, ask at your uni/highschool/local hakerspace.

>>795497
Go digikey.ca, shipping is 8$ (at least to BC)

>Unfortunately, Toronto has a sad lack of electrical equipment sources ...
I don't believe that for a second. How hard were you looking? There are two places in my town of ~100k that sell electronics, Toronto's got to have some places.

With minimal googling I found these:
www.a1parts.com
www.sayal.com
www.active123.com

>>795672
In all honesty I'm just a lazy cheapskate who wants my stuff shipped to me nice and simple with no extra charges which includes shipping. I know the first one charges $12 for shipping but I'll go to the latter two and see what they have.
>>795667
I also forgot to mention but the CAD is really weak. That shipping + import tax will need to be multiplied by around 1.25 which is the cost I will be paying. No thanks.

>>795557
That sounds encouraging. I'll order this then if there's nothing wrong with it.
>>795672
In all honesty I'm just a lazy cheapskate who wants my stuff shipped to me nice and simple with no extra charges which includes shipping. I know the first one charges $12 for shipping but I'll go to the latter two and see what they have if anything I need more. I have this chinese brand solder which I thought would be good enough but maybe I'll try finding some good stuff as well.
>>795667
I also forgot to mention but the CAD is really weak. That shipping + import tax will need to be multiplied by around 1.25 which is the cost I will be paying. No thanks.

HI, one question, I want to do a supply voltage with 3 options (9v, 5v, 3,3v) with a switch each.

I have 9v what's the best way to transform to 5 and 3,3 without wasting much power, two regulators? voltage divider( after the switch)?

in the pic buck converters are used, but i want to do something simpler

>>795612
Don't buy flux pens from eBay unless you can verify what you're getting. Almost all of it is counterfeit garbage, and although it shouldn't be difficult to make basic rosin flux (the patents have expired), all the ones I bought burst just sitting in my toolbox.

Hey guys, i kinda always got interested in learning the eletronics of general sound equipments and some instruments , would you have any books or online material to indicate me ?

>>795881
Would you have anything to recommend me on learning radio eletronics too ? I always had some kind of interest for this kind of old-fashioned tech

>>795699
>buck converters are used, but i want to do something simpler
>without wasting much power

literally pick one.

I thought antennas were just some wire or something.

What's all the extra circuitry and metal case for?

Also do the traces pick up the radio waves?

RF is confusing.

>>795953
Antennas pick up a lot more than they're inteded to, thats why you need extra circuitry, to filter unwanted signals out and boost/amplify wanted signals.

Everything metal picks up radio waves, pretty much. And everything metal you put electric current through will emit waves as well. Hence the metal case, blocks shit getting in or out.

>>795953
This is a front end, i.e. the first amplifier stage after the antenna. There are various amps/transistors and filters in here, implemented in stripline and copper shapes.

>>795953
The antenna likely had some hardware based demodulation circuit which is what the extra circuit likely is. Also if the same antenna is used for transmitting then the circuit of course gets more complicated.
http://en.wikipedia.org/wiki/Modulation
http://en.wikipedia.org/wiki/RF_modulator

The extra metal is likely for shielding the more sensitive circuitry. So yes, traces do pick up radio waves.

Maybe this hobbyist blog will help:
http://ludens.cl/

>>794825
>who may suffer from mild auditory hallucinations
Diagnosed?

>>795953
well, that is partly true. well mostly true.
all antennas start as pigtails. which is just a piece of wire exactly the length of one wave on the frequency you are trying to pick up.

but that's usually impractical so they use fractions of a wavelength. then you put up some waveguides which mostly reflect a rough range of signals you want, again by having wires in the same fractions of a length of the wave. then you have reflectors which direct the waves that go past the waveguides back onto the recieving element.

but with 2D printed antennas you can use all kinds of funny shapes. the point isnt to get a wire of a multiple of a 1/4 wavelength, but that happens to be something that resonates at that frequency. so if you can make a shape that also resonates at that freqency then that will work as well.

that board has multiple antennas so the filter and amplifying circuitry needs to get the signal those antennas receive to the receiving element synchronized so the signals arn't staggered. also, basic upper/lower pass filters.

>>795953
>RF is confusing.
RF is black magic.

/g/entooman here. I'm trying to identify the ICs on a PCB. I can't for the life of me figure out what pic related is though. Googleing it just leads to tons of pages selling it (without explaining what it is) or pages claiming to have the datasheet (that don't actually have it). Is there a god-tier database of ICs somewhere? How can I figure out what it is?

>>796171
My guess would be stepper motor driver, since its output is wired to disk motor connector.

>>796174
>since its output is wired to disk motor connector.
How can you tell?

>>796171
The logo on it means it's a Texas Instruments part. So if you can't google up the datasheet easily that means it's a custom job and there no public datasheet available.

>>796185
There seem to be third parties selling them en-masse though. For example http://www.jotrin.com/product/parts/sh6962

>>794221
What is that electronics for virgin no gf weeaboo losers?

Jesus Christ

>>796190

/ohm/ - no fun allowed

Why do Maxim RTC chips cost $3.5 or more in singles while Microchip RTCs can be get for <$1? Are microchip ones somehow crappy or what?

>>796193
look at the current consumption and stock, the maxim is clearly a much older design using a larger more expensive process where as the microchip is far newer and likely still in production, that maxim is just around for legacy support.

>>796187
There are plenty of things you can buy but not get an official datasheet for.

>>795398
That's not true.

Consider a maze represented by a line drawing. Now draw another line all the way around it with one break in it.

You now have a maze not solvable by the follow-one-wall approach.

>>795398
>>796209
It depends on your definition of "maze".

Most traditional definitions of a maze are of one that is acyclic, and thus having only one wall.

>>796215
Fair enough.

>>794221
Where can I find projects for AVR Butterfly, do you guys have any?

Teensy LC input voltage is 3.7-5.5V, but the MCU within is rated 1.7-3.6V. Can I somehow easily power it directly from 2xAA (1.8-3V)? I suppose it has some sort of voltage regulator onboard that I'd need to bypass...

>>796187
Protip: those kinds of websites rarely actually have the chips they're advertising, they're more like catalogs of all ICs that have ever been entered into some kind of data system. They're part brokers, part scammers. If you try to order a part they'll most likely ask their network of sources who are similar brokers, who will ask their sources, and on and on until they either turn up empty handed or find some shade Chinese seller who can supply some refurbished or counterfeit parts.

>>796185
TI might be acting as second source, or it's originally by some company bought by TI. In either case, the case markings might not have the "popular" name.

>>796244
just back feed your battery into one of the 3.3V pins, it'll work fine just don't expect the processor to run at full whack without lockups once your battery starts to go bad.

I'm trying to build a toy that will loop a 4 second sound byte when it receives power and have been looking at using a WTV020 IC. In the datasheet there are two separate sample circuits for this mode, one using edge triggering and the other using level triggering. In layman's terms can anyone explain the difference between these two?

>>796290
I'm guessing that in the edge trigger configuration, you have to press the button to start playing, and press a second time to pause. In the level trigger case, sound plays as long as the button is held down.

>>794223
Am I looking in the wrong place or are nixie tubes expensive? They look so cool but...

>>796333
Yes they are expensive but they are actually worth the price. It just sucks when you have to design your own clock because the costs will be really high. Mine cost about 400 to make and I'm even making a second one with IN-8-2!

>>796333
look up in-14 tubes
cheap as hell, i'd be surprised if the whole clock would cost you more then 50$ and that's generous

>>796290

he's right
>>796313

most specifically edge trigger sets a play loop that doesn't terminate until finished but level trigger requires the button to be held down the IC i'm using here: >>794825 has a similar feature

>>796290
most specifically edge trigger sets a play loop that doesn't terminate until finished but level trigger requires the button to be held down the IC i'm using here: >>794825 has a similar feature

>>796036
not yet

>>796377
>>796313
thanks, on that ISD1820 can you program the audio over serial or something digital, recording from a microphone doesn't seem like you would have quality audio playback.

>>796333

Price varies. I got mine as new old stock so it cost more, but don't expect them to be very cheap (they'll be > $4 per, almost guaranteed)

>>796352

$400? damn. I'm in it around $110 now and that includes the IN-14 tubes shown in my video (12x), drivers (12x), and the HV supply. Did your cost include the PCB and whatnot? What did you do for the housing?

>>796400
no audio over serial just mic, quality is ok, but one could always forgo mic and use a shielded audio cable and preamp on chip end this would greatly reduce noise.

>>796401
12 digits? That's pretty impressive. Id like to see the finished product. Is it based off that new York clock?
Mine includes a PCB and such, I've bought it off a guy and I'm still in the process of making it. For housing, I used aluminum sheet metal and corner hex posts.

>>796433
>>796401
Speaking of nixie tubes, one of the leads of my tubes has a little chip in it. Is that a concern?

>>796390
Almost certainly going to be placed in the 'schizophrenia' category.

Antipsychotics are very dirty drugs.

>>796485
I'm working on converting a formerly bolt action CO2 air rifle (shoots metal pellets) into semi/full auto (select fire) through using electrical actuators.

Now before you say this is against board rules, the gun itself is pre-made. The electrical components is my focus.

I already plan on using a servo motor to work da bolt.

Now the issue is what to do to trigger the hammer valve. Normally, it is triggered by a block pushed by a spring hitting it.

I was planning on coupling a plunger to the servo to push into the hammer valve at an appropriate time, but I realized this might make it very mechanically complex. It would also increase the amount of work the motor would have to do which would lower my cycling time.

I had another idea of using a small solenoid to hit the hammer valve, like here:

https://www.youtube.com/watch?v=5lFqwXwhZ-M

However, I don't know if the solenoid will be forceful enough and I'm not sure if the solenoid would provide enough control to fine tune how long it keeps the hammer valve on.

I'm working on converting a formerly bolt action CO2 air rifle (shoots metal pellets) into semi/full auto (select fire) through using electrical actuators.

Now before you say this is against board rules, the gun itself is pre-made. The electrical components is my focus.

I already plan on using a servo motor to work da bolt.

Now the issue is what to do to trigger the hammer valve. Normally, it is triggered by a block pushed by a spring hitting it.

I was planning on coupling a plunger to the servo to push into the hammer valve at an appropriate time, but I realized this might make it very mechanically complex. It would also increase the amount of work the motor would have to do which would lower my cycling time.

I had another idea of using a small solenoid to hit the hammer valve, like here:

https://www.youtube.com/watch?v=5lFqwXwhZ-M [Embed]

However, I don't know if the solenoid will be forceful enough and I'm not sure if the solenoid would provide enough control to fine tune how long it keeps the hammer valve on.

>>796190
I'm not sure if this is a real post or an elaborate hoax, pretending to be trolling but actually just being ironic.

I need to get more sleep.

>>796501
I'm guessing that's a misquote.

>>796433

It's not going to be 12 digits long; first is a divergence meter based on Steins;Gate, might do another clock with 4 digits after that.

>>794484
>what is cost-saving

I support it, it's readable.

that's like complaining LCD character screens aren't in cursive.

>>795126
>>795097
>>795105

what are you talkig about?
you can just use the pickit 3 programmer.

it's as good as any other and has full debugging support.

pic related is all you need for PIC8, PIC 32 is the same but different pin names.

the pickit 3 has 6 pins:
ground, vcc, miso, mosi, reset, and soemthing else that I never use.

>>795410
why change the delays? if they're too short the LCD will misread shit

I've used the same LCD code in like 3 of my projects now and every time it has been a bitch to actually get something running, maybe I'm just a shit programmer.

>>795563
>>794762
>>794591
>>794557
>>794574

I'm the anon who wrote the OP.
I made this for us, what do you think?

>>796548
Rolling

>>796502
So I figured out that I would need a capacitor circuit if I were to use the solenoid to actuate the hammer valve.

I understand that the capacitor would need to recharge after every shot and that takes a little time. Is there a way to minimize this for the full auto effect?

>>796563
Have a bank of capacitors rather than just one similar to a coil gun.

>>796548
Wonderful.

>>796565
Looks like you get to make a launchpad, swifts. :^)

Electronics is programming for people with cash to spare :-(

>>796567
ehhhh

I'd rather go for the LED tach since I plan on making a gauge cluster for my ATV anyways.

>>796548
change "dont use arduino if you can avoid it" to "don't use arduino ever"

if they have to use a microcontroller they have to do it from scratch too, like a barebones ATmega or a PIC setup

>>796563
You just want to mod a gun to work on electricity? So not a railgun?
Hook up a lipo battery to a decently sized capacitor array/bank. Be careful to limit the heat on the battery, you don't want it to blow up in your face.
The capacitor charge would be used when you shoot faster then the battery can handle. You might have to just experiment with it. Just realize that the initial chargeup of the capacitors will draw a shitload of current.

>>796620
This isn't /EE/ faggot
Arduino gets the job done. Not everybody is interested in learning microcontrollers.
What is it with the attitude some of you have.

>>796548
>Use of microcontrollers [...] are frowned upon in projects that can be done with them
Perhaps review that sentence

>>796620
Here's the thing, I agree to an extent. Arduino is meant as a prototyping tool to make sure a circuit could work but it's definitely not a final solution. That's not to say you should never use it, you should just treat it as test equipment.
Someone shouldn't use a breadboard in a final product, but at the same time I'm not going to say they shouldn't use breadboards period.

I probably should've worded it like that when I wrote the challenges, I could rewrite it later.

>>796644
Yeah I just noticed that. I wrote this at 3am heh.
Although I, in my infinite wisdom, used paint.net rather than gimp so I'd have to redo the whole thing since you cannot edit text after it's been written unless you delete the whole layer. Paint.net is just paint with a little more bells and whistles. Definitely shouldn't have used it for this.

>>796507
Ah I see. In all honesty, it would've been more like 250 if it weren't for extra shipping costs and the awful conversion rates. I just hope I can make a IN-8-2 meter, I literally have no idea how to start off.

For a newbie with dreams of being able to make my own guitar effect pedals, would you guys recommend starting right away in that direction (buy a premade kit, build it on a breadboard, start messing with it), or would it be better to start from more basic circuits (like LEDs and whatnot)?

I had my first electronic circuits class this semester so I have a general idea about components and circuit segments already, just no practical side except for some multisim.

>>796706
Guitar effect pedals and audio equipment actually have their own niche threads here on /diy/. I don't know much about them, but there's a couple of anons floating around here that do exclusively that.
I'd suggest learning starting with basic circuits if you don't have experience actually building them. The last thing you want to do is buy an expensive kit or parts and fry the components due to inexperience.
If you feel confident in your ability to not destroy parts, then it's always good to dive headfirst into something you want to learn.

>>796628
Electricity will be used to cycle the gun and activate the hammer valve. See >>796502

>>796645
After finding out that the Arduino atmega line of boards are essentially a fancy breadboard with a chip stuck on it and that the chip can be used seperately after being programmed, I can kind of get behind that. Stick it on some empty board and solder the connections. Though, considering the cost of minis, I'm likely to only ever go that route since they're cheap as fuck and already come attached and wired to their holes.

I wouldn't be sticking Unos into all my devices, even the knockoff ones.

>>796809
Do people actually use the entire Uno board as the main circuit for a device?

>>796812
I see it more often than someone only using the IC. I mean, it's kind of ugly and messy to do so but if it's all hidden in a box or whatever, what's the big deal outside of being expensive?

my CNC runs on an uno + shield. I could break that down into something smaller if I wanted to but it's already such a tidy package that I haven't bothered.

>>796809
>After finding out that the Arduino atmega line of boards are essentially a fancy breadboard with a chip stuck on it
The people here don't want you to use their language as well, because it abstracts things away from you.
That's where I draw the line.

>>796809
Honestly, I don't even mind the Arduino being used despite 90% of the projects made with it can be done with an ic and fewer components. Mainly because Electronics as a hobby was declining in interest in the early to mid 2000s as programming took over as the nerd hobby. Things like Arduino and Raspberry Pi are getting people interested in electronics again and helping to bridge the gap between programmers and engineers.

>>796824
Arduino is a fairly big and accepted part of electronics.
I mean, next year in school we're going to be learning how to use Arduino and we're going to be doing it in the class that teaches us how to work with PLCs right now.

>>796825
Huh that's neat. I didn't realize Arduinos were actually a part of the curriculum now.
I suppose it's only a matter of time before we start seeing a lot more Arduinos and general purpose microcontrollers in industry.

>>796645
Arduinos were intended as a building block for people who needed electronics in their art projects, but didn't necessary have the skills to build or program it from scratch. It's a tool and a building block, and people (not directed at you) should get off their high fucking horses. Use what works. Snobbery doesn't get you anything.

>>796824
>>796825

I, along with other people that are resentful of Arduino, should realize that even though they are not a great tool to learn electrical or digital circuit engineering they have really helped to build a sort of infrastructure information around hobby MCU and the like. I mostly use PICs and typically only code them in assembly but there has been many times when I need to understand how to interface IC x with a microcontroller only to have it explained by someone writing a tutorial for an Ardunio.

Of course without Ardunios this knowledge would still exist but there wouldn't be so many people writing concise clear explanations of the technology.

>>796833
As a sidenote, using something like an Arduino uno in a final product is pretty retarded.
Use one of the smaller models(pro mini for example) and drop them in a dip socket if you can't produce a custom PCB.
If you can there is no excuse to make one and just use the atmega chip itself. Using the Arduino language is fine if you want to get shit done. Not everybody wants to learn the internals.

>>796833
I think both sides are valid. Nothing wrong with using an Arduino if you've got it, and it's great that it's so simple.
That said, the price difference between a board and just a plain chip is pretty much the whole price of the board.

>>796833
>>796834
Right, I think it's mostly just a changing of the times. This sort of makes me wonder, do you think electronics hobbiests disliked the transistor at first because all the experienced hobbiests at the time dealt with vacuum tubes which were a lot more difficult to use? What about the IC at the time?
Give it about 10-15 years and things like the Arduino will probably be standard for quick projects and there will be something else everyone groans about since 'that's not the way we did it'

>>796838
You still have people that prefer vacuum tubes for music, take a wild guess.

>back in my day we had to work our ass off
Sound familiar?
That's how you sound like if you complain about this.

>>796839
Exactly my point, people are going to complain simply because it's different.
My father was an electronics hobbiest when he was a kid, much like I was, but he absolutely detests Arduino and microcontrollers of the like. I actually like them since they make quick and easy projects possible without wasting hours of time.

Comparing it to programming, I'd consider the Arduino to be the IDE of the electronics world.
Some people hate it, some people can't make anything without it. It's a handy tool, but it can become a crutch.

>>796838
>>796839
>>796844

but that's just it. It's not some generational warfare thing when you see 10000+ idiots building projects using an Arduino when a simple 555 or even a transistor will do were do you draw the line if your intent is to actually learn about digital electronics. It's not old men being cantankerous.

The analogy between the transistor and tube is completely false. A transistors is, for most applications a better replacement for a tube.

An Arduino for many applications it's used for isn't.

Learning how to use a tube or a transistor in a circuit requires and imparts knowledge that has broad applications. Learning to use Arduino libraries for the most part simply teaches one to use Arduino libraries.

I mean I see kids that can't even figure out correct resistor values to use for an led or understand current and voltage call me an old fart at age 29 but I learned that stuff at 10 when I first started getting into electronics.

>>796871
Perhaps in the beginning, but I feel like eventually learning about different components is a natural progression of wanting to do different or more complicated things. In the beginning I just wanted a step-by-step of how to put everything together. I wanted to have something work without me having to first go learn all the funamentals. Now that I'm past that and looking at more homespun solutions, I have to learn about this or that component since I find out I need to use it. Like MOSFETs. No idea what they were or did until I found out I'd need to incorporate them into my build.

Lots of people don't want theory in the beginning. They want Lego before they get to mindstorms, basically.

>>796871
>your intent is to actually learn about digital electronics
Why do you assume this is their goal again?

>>796877
Well when I see them used in engineering classes and science classes and by people who say they want to get into electronics who have had them recommended to them by other people who claim to practice hobby electronics I just assume.

Note I didn't say this was the case with ALL uses of the board, but in many cases among a certain segment of the younger generation this is the case.

"How do you blink an led?"
"well you start with an Arduino..."

>>796882
Most people learning electronics aren't doing it for the sake of electronics anon. It's a means to an end.
You don't teach someone that doesn't know how to computer about the cpu and it's registers and how everything is just memory operations. Just teach them how to use the mouse/keyboard and how to use the needed programs.

>>796876

>Lots of people don't want theory in the beginning.

but you need theory coupled with application to understand.

Depending on your goals that may not be important(I see a lot of "art" type projects where the user of the Arduino probably won't need to know much beyond that application) but if the idea of getting kids interested in electronics and more broadly STEM in general you're not going to prepare them by watering down the knowledge they need.

Also why is it such a taboo the expect people to learn MORE than what they need to know?

So what if you're an art major why is expecting you to learn ohms law considered a perversion thrust upon you by a dirty grand pa(or in other words and rf circuit hobbyist) ?

>>796887
>Also why is it such a taboo the expect people to learn MORE than what they need to know?
When you grow up you'll realize time is the most valuable currency.

>>796886
But why not? Why are they not expected to know more? Why shouldn't we teach kids about memory registers and von neumann architectures and model machines?

Why does it make you old and outdated to expect people to learn fundamental principles of the technology that they are dependent upon everyday?

>>796889

Because it's the equivalent to teaching a soccer player how his shoes are made, how the playing field is prepped and how the ball is made perfectly round.

>>796888
that's bullshit broadening your knowledge base is the most valuable thing you can do with your time.

If you're not a completely unhealthy you'll live 70+ years plenty of time to learn new things.

I think it boils down to effort. that's what most are really to afraid to spend.

Well that just depends on the level of education they're getting.

If I'm going to hire someone and actually have them to design something I sure as fuck expect them to know the founding principles.

But there is no need to force all that on someone that will never make use of it.

>>796891

false analogy, A soccer player literally only has to play soccer. Every other moment in the modern world requires you to interact with this technology literally the entire future of the whole of human society probably exsistence depends upon understanding technology. It's not the equivalent of a soccer player needing to know how soccer shoes are made(which I will point he might want to know in order to select shoes that are quality for playing soccer) but the equivalent of a hunter in a hunter gather society needing to know how to make a bow and arrow, how to stalk game.

These are just excuse for ignorance.

Electronics is a rabbit hole that allows you to go as far as you want to. You'll never learn everything, but you barely need to know anything to get something to work.
Arduino helps kids from the ADD generation to get into something that requires patience like electronics. It lets you make good inventions, but nothing fantastic or great since you're limited by Arduino's capabilities.
Anyone who considers themselves an electronics hobbiest will eventually move above arduino and get passed it, but it's not a completely horrible way to start for someone who wants to know what they can do.
Let's be honest, blinking LEDs don't sound very interesting and a low-pass filter sounds like a medical condition to someone who doesn't know anything about electronics. So, being able to jump in and build something exciting with Arduino is a decent stepping stone to help gain interest
I think it's really good for kids and beginners, it's also a good prototyping tool, it's also a good thing to build projects quickly.
However, it shouldn't become a crutch and anyone serious about the hobby will eventually move passed it.
People being evangelical about wanting the arduino to die are just as bad as the people who only use the Arduino and call themselves hobbiests.

>>796899
>a low-pass filter sounds like a medical condition to someone who doesn't know anything about electronics
my sides

Electrionic newfag here. I am trying to design a class ab amplifier for a pair of 3W speakers i have. However I want to bias using a Vbe multiplier but am confused on what I bias should be and what transistor (i know it needs to be npn) to use for the Vbe multiplier. Also not sure what to use for R1 and R2. I am using the TIP 31/32 currently.

Literally any help is is wanted as the internet just seems to keep confusing me

>>796882
>>796871
>you see 10000+ idiots building projects using an Arduino when a simple 555 or even a transistor will do
That's an issue for applications where a microcontroller isn't the most practical solution; in many cases it's cheaper and easier to use one. Yes, you do have people doing really simple things with MCUs, but they could very easily be doing that to learn more about them.

Like, with your blink-LED example, having that as your first MCU project isn't an issue. It has very little margin for error and it demonstrates how to use a pin as an output. It's starting with the basics. People who think that blinking an LED *requires* a MCU, I'm just going to go out on a limb and say those people are few and far between and 100% non-existent if they've had basic education in digital circuits.

For applications that do require/are best accomplished with a MCU, using an Arduino is usually due to the fact that the Arduino has tons of documentation. For someone who is making something where manufacturability isn't a constraint (i.e. 99% of hobbyist projects), the disadvantage of using an Arduino over a PIC or AVR is... you don't learn much about using PICs or AVRs. I think that's the only risk when learning from an Arduino, you risk learning how to use an Arduino and nothing else... but it doesn't take a genius to make the connection between pinmode() and TRISX, and if you don't know anything about circuits the Arduino can't compensate for that.

>"Hey why isn't this switch working on my arduino"
>[googles problem]
>"Oh it's because I need a pull-down resistor, now I know what that is"

>>796908
>TRISX
God is wish it was that simple
Enjoy my final project for the first year:
http://pastebin.com/PwyTakDq

All it does is avoid collision based on 3 infrared sensors. It drives on 2 wheels.
This could be just a few lines in an arduino.

Retard here
How do I ground something? Since everything must eventually reach ground, do I make all connections come to this one ground source? And what can even act as ground? Also how do I ground myself? Can I stick a little metal rod into the ground part of an electrical outlet and touch it every so often to ground myself and prevent electrostatic damage to my parts?

>>796910
In simple terms, ground is something that:
-is at 0 volts
-is large enough that it can absorb charge while remaining at roughly 0 volts

You don't need literal ground to do this, e.g. a lot of guides for assembling computers will tell you that you can ground yourself by touching the computer's case. Electronics in airplanes use the chassis as ground.

>Since everything must eventually reach ground, do I make all connections come to this one ground source?
I don't understand your question here.

>>796909
doesn't look that rough I'd of done it in assembly

>>796917
The point i'm trying to make is that it's unnecessary. The goal of that class was to learn how a mc roughly works. Most of our classes were about the mechanical part of things.
If the goal was to make a non-crashing car it would be madness to use that platform.

>>796882
>It's not old men being cantankerous
>among a certain segment of the younger generation this is the case

>>796916
I've seen in most schematics that some connections go to ground. Do these all go to the same ground?

>>796927
No, ground is a loose term for anything that has 0 volts and stays at 0 volts through the operation of your device. Virtual grounds exist too, look up op-amps

hey, where do I go to learn about signal types and hardware implementations? like i know basics of digital circuitry (gates, adders, shift registers, state machines), i know how to do a thing or two in arduino, but I cant figure out how USB works or how ethernet works. I dont know how to implement things in software because I cant find guides that explain what arduino commands do at more basic levels. hell, i dont even know where to begin when it comes to using standalone micro controller chips. where do i go????

>>796929
What about in small devices. Where is it grounded?

>>796938
To the body usually.
Think of what voltage actually is. It's the electric potential energy between two points. Voltage doesn't exist in one spot, it's a difference.
If the whole device has a potential difference of 9v from the device to earth but it is not connected to earth then the device has a potential of 0v across itself.
Think of it like this, if I fill a tub of water with a liter of water and raise the entire tub up 2 meters, the water level rose by 2 meters with respect to the ground but remained constant with respect to the tub.
The water will only flow if there's something that allows the water to leave that system and enter the earth's system. (e.g. a hole) then the water will flow down towards the lower potential.
Same thing with electricity.

>>796938
In 99% of all small devices it's the negative(-) pole. PCB's usually fill the leftover space with the ground plane.

>>796946
So it doesn't have to be a closed loop?
This has been irking me for a while and I got mixed answers in the past.

>>796949
Yeah it has to be a closed loop since you cannot create or destroy energy in a system.
According to Kirchoff's circuit laws, energy going into a system must be equal to the energy leaving the system.

If you get shocked from touching a doorknob, it's because the doorknob had a higher emf than you and so it diffused through you to get to the ground's system. However, everything is still within the system.
A battery works by creating anodes and cathodes, when it creates the electromotive force, it also creates an absence of electrons on the other part of the battery. The best way to get the electrons to flows is to have them travel through your circuit to get back to the void of electrons it created.

If you connect your plate or your body to the void you created, then anything connected to the plate will go to the void or 'ground'

So, yes it has to flow in a loop within a system since energy cannot be created nor destroyed. However, energy can hop from one system to another since they're in the same universe and no net energy was created or destroyed.

>>796952
tl;dr current can flow without having a closed loop, but the object that's discharging needs to be charged first.

Your answer is too much details.

Anyone have links/pics of wiring minimalism, for lack of a better term? I derive a lot of pleasure from looking at circuitry being reduced/simplified as much as possible. e.g. arduino prototype > prototyping pcb > custom pcb. Love seeing all the wires organized, the ruthless economization.

So i'm kinda learning for an exam on monday
It's about AC circuits
The thing that isn't really explained anywhere is: What the fuck is the phase angle relative to? The input voltage? The voltage over the component(capacitor/inductor)?

>>796996
difference between phase of the voltage and phase of the current.
you could have probably googled this

>>796935
http://janaxelson.com/usbc.htm
This is IMO the best book on USB, though the newer editions kind of gloss over some things to keep the page count under control.

Do you actually want to know about Ethernet, or TCP/IP networking? For the latter see TCP/IP Illustrated Vol. 1, and UNIX Network Programming Vol. 1.

If you know C and C++, download the ATMega168PA documentation and the Arduino library sourcecode and start reading.

>>796909
That's less than 200 lines. Not to be coarse, but I poop 200 sloc.

>>795354
buying a bunch of andurino stuff and loading premade code isn't exactly EE though

I think the micro usb port in my phone is broken, is it possible to charge the battery directly?

If it is, which pair of wires do I connect the +/- of the charger?

Also does anybody know what those yellow wires are for?

Sorry for the low quality image, I'll take a better one as soon as I can.

>>797158
It might be easier to replace the micro usb port.

>>797162
I'm gonna do that soon, I'm just curious though. Thanks anyway.

>>797158
>charge the battery directly?

What do you mean by that? Do you want to remove the battery from the phone then charge it, or leave the battery in the phone and provide power to the phone's charging circuits?

The first option will not work. You can't just stick a battery on a power supply and expect it to charge effectively and safely. You need a charge controller circuit to prevent things like overcharging. Your phone has one, so you just need to connect 5v/gnd and it will take care of the rest. Simplest way for you to do this is to solder wires to the PCB where the broken USB connector is. 5v to Vcc.

>>797158

Some batteries have optional charging stations available.

>>797135
Yeah, maybe now, but not when you were a nooblet.

How do I run my circuit in Fritzing to test if it would work?

>>797236
I don't think it has a simulation tool.

>>797236
Ohh god these connections are so retarded....

>>797211
>detected ghosts
3spooky

>>796548
roll

I plan to convert my florescent tube lamp to an LED lamp like pic related, the assembly thing is water clear, but I don't know how to power the LEDs.
Is there a (efficient) way to power them directly from rectified 230 volts just limiting the current without any transformer? Or I'll have to buy a PSU?
I was thinking about storing the rectified 230v in a cap and using a 555 PWM dimmer circuit with a fixed maximum duty and a smoothing cap so the LEDs don't fry.
I guess there must be a better way to do this, no flickering pls.
I'm going to buy two 10W LEDs since 100 watts is way too much power.

>>797339
what do you mean? power them with any ac to dc adapter. I make lamps with old 5v phone chargers all the time.

>>797504
>>797339
or upon reading your post again old wall warts would great so would old top power supplys

>>797504
>>797507
I plan to use two 10W LED, after looking for the specs I've seen they work with a voltage around 9v to 12v, that means 24v in series. Either I need a wall-wart that can deliver 24v ~0.83amp or 12 volts ~1.7 amps. I don't have any of those.
It's a shame, because I want to add a 555 based dimmer, and I can't figure out how to do that from the mains.
I'll try to search in my junk boxes for transformers, maybe I'll have to add a third LED to compensate for voltage drops, it shouldn't matter in terms of power if I add the 555 dimmer.
I'll be looking for a better circuit, also, for the switching transistor I guess a irf540 will work fine, it has a resistance of 0.077ohms or 77mW of power dissipated with 1A.

>>797557
can you show us specs on leds you wanna use?

>I plan to use two 10W LED, after looking for the specs I've seen they work with a voltage around 9v to 12v, that means 24v in series

Either way hit up thrift shops for old laptop power supplies if you want to use cheaper option.

>555 dimmer.

You don't have to use mains voltage you simply need an adapter with voltage output and current capacity you need coupled with appropriate resistor. If this power supply is not regulated then you will need to acquire voltage regulator. (don't know what country your end but if you're an Ameriburger such as myself fleabay is your friend)

one simply needs to use output of 555 dimmer with transistor rated for voltage and current of leds the 555 circuit in turn will need its own voltage regulator or ate least resistor appropriate for voltage and current draw.


So basically finding a simple regulated power supply would be the cheapest option. Old laptops adapters would be good but some old wal-warts would work as well.

>>797586

oh I forgot to add you could simply use an old light dimmer or any other variable resister rated for that wattage

>>797586
>>797587
Ok, my best bet right now are the transformers I have lying around, I'll test them to see if there's one near 24 or 36 rectified DC. It will be easy to add a dimmer if that's the case.
I've found circuits similar to picrelated, but I don't think to use them because I can't calculate the components value and I don't know hot to add a dimmer there.

>>797586
>>797587
Ok, my best bet right now are the transformers I have lying around, I'll test them to see if there's one near 24 or 36 rectified DC. It will be easy to add a dimmer if that's the case.
I've found circuits similar to picrelated, but I don't think to use them because I can't calculate the components value and I don't know hot to add a dimmer there.

>>797819
well in that circuit a dimmer would go after your 10 uf cap in series with leds.

any guess to which goes outside and which goes inside?
from the way it was soldered, i'd say black outside white inside, but i'm not really sure

>>797838
It depends on the appliance, normally the positive goes inside and the negative outside, check with the multimeter. If it's a wall wart check the label for info about the connector polarity.

So after a few days of reading i have good grasp on induction, electromagnetism and Maxwell-equations, what should i read to get up to speed on different kinds of electromotors?

what's the weirdest device you guys ever bought? Within the context of electronics, of course. I just bought a thermocoupler and I made a minifridge using a plastic lunchbox

>>797819
you really shouldn't put diodes/leds in series

>>797878
One of my professional engineering jobs turned into a MacGuffin fetch quest in foreign land. I designed some monitoring equipment to connect to the early 80's computer equipment at a Chilean power plant, but when I showed up it turned out they were missing an important module needed for the interface. I went to professional engineering offices, pawn shops, junk collectors, everywhere. I eventually tracked down a factory that had one installed but wasn't using it for anything.

>>797918
You're talking out of your ass. There's no problem with putting diodes and LEDs in series.

Can anybody hand-hold me through making a clock with non-standard, custom-built digits? {Not 7 segment digits}

I took robotics like a decade ago, but did poorly with electronics, and I need a quick review. Anyone know of one? I'm bad at research.
Though I did well on the microprocessor class because of my previous experience coding.

>>795104
I posted a bit in this thread, so I've got some idea on how to make the custom LED bars, I think.
I wonder if I could make them more efficient with a certain shaped lens that keeps it narrow but spreads it out along that narrow strip. Do those exist as products?
Is it worth it to make the walls of the bars reflective?
RGB LEDs might be nice so they could either change by time of day, or just have them a nice purple color.

I'm guessing I'd need an Arduino, with a separate module for the clock {?}, and shift registers for each digit. {I'm unfamiliar with shift registers, though the concept seem simple enough. Is 8 the highest number of outputs one can have? So like the person in the other thread said, I need two in cascade per digit?}
Will I really need 5 wires from the Arduino to the shift registers? How many of those wires can be shared by different digits? because I need to use the minimum so I can make the digits somewhat modular. I don't know what a latch is, but I'm guessing voltage, ground, and clock can be shared, and then data is unique.

Also, is there any point in trying to sell it as a commercial product, or is it not unique enough, even with an odd font? Is it possible to patent it? eg: was the first person who thought up the 14-to-16-segment starburst display able to patent it? Considering Apple can patent "round edges on cell phones" you'd think anything easily invented but applied in a specific way could be.

>>798265
>Is it worth it to make the walls of the bars reflective?
Commercial LED displays often use reflective (white) walls inside each segment.
>Is 8 the highest number of outputs one can have?
No, byte-wide shift registers are just common. You can also get shift register -like LED driver chips which can handle dimming as well.
>Will I really need 5 wires from the Arduino to the shift registers?
It depends on your shift registers and how you connect them. I2C shift registers need only 2 pins. SPI shift registers need more, for example 2 common pins and 2 additional pins per register. Or you can chain them and manage with 3 pins. Plus you need power supplies, of course.
>I don't know what a latch is
In this case it would be the output latch. Pulsing it would load the shifted data to the outputs.
>data is unique
You can manage with one data pin, if you chain the registers so that they form a one (logical) long register.
>Also, is there any point in trying to sell it as a commercial product,
Ever been to a clock shop? If your thing looks different than the others, someone might want to buy it.

However, it sounds like you're going to have hard time building your very first clock. IMO you shouldn't worry about markets and patents and other garbage at this point.

>>794223
New guy here. What's lighting up those numbers?

>crickets.avi.mp4.jpg.exe.mkv

>>797819
Why is there smoothing R/C on the AC and the DC side?

>>798274
They're called nixie tubes: Ten small neon lights each in the shape of a different number and put together in one glass case. They were common in the 50's before LEDs and LCDs took over.

>>798270
Oops! I meant to rewrite my post better.
Thanks for the reply.
I don't think I asked it in that earlier post, but is an ATmega 328 the best option for me? It still requires an Arduino to interface/code but at least I don't need the Arduino in the clock. I don't really know what to search for and start reading in-depth. My library also has an Arduino if I don't just buy one.

>Commercial LED displays often use reflective (white) walls inside each segment.
but that also bleeds light, unless they take measures to put something denser in between. I know the surfaces are black, but I don't know if it's just painted. I wonder if it's black plastic that continues in between the bars. Maybe I should smash one open to look.
I wonder what's a good LED to use for this. The kind in translucent cylinders seem common, but I wonder if there's any advantage to the tiny ones that sit flat on PCBs.

>If your thing looks different than the others, someone might want to buy it.
Oh it's very unique. I just hope it's not too bizarre. I'm giving up legibility for exoticism.

>>798274
A high voltage DC (normally around 100 to 200v) applied between the electrodes makes the neon surrounding the number shaped filaments glow.

>>798310
>100Vdc
Wait a minute. How does one get that much DC? Step-up transformer?

>>798270
>re: help making a digital clock with custom, non-standard, multi-LED digits.
Oops! I meant to rewrite my post better.
Thanks for the reply.

I don't think I asked it in that earlier post, but is an ATmega 328 the best option for me? It still requires an Arduino to interface/code but at least I don't need the Arduino in the clock. I don't really know what to search for and start reading in-depth. My library also has an Arduino if I don't just buy one.

BTW, do you load the data in the shift registers from the micro-controller every time the device it powered up,

>Commercial LED displays often use reflective (white) walls inside each segment.
but that also bleeds light, unless they take measures to put something denser in between. I know the surfaces are black, but I don't know if it's just painted. I wonder if it's black plastic that continues in between the bars. Maybe I should smash one open to look.

We have 2 tiers of 3D printer and a laser cutter. I guess the 3D printer would be easier for the base, and the cutter for the surface panels, frosted/sanded on one side.

>If your thing looks different than the others, someone might want to buy it.
Oh it's very unique. I just hope it's not too bizarre. I'm giving up legibility for exoticism.

>>798304
Real ones are actual vacuum tubes, and those are filament anodes. They're incredibly intricate.

>>798311
My little inductor: Magnetism is magic.
A step up transformer works by feeding pulses of DC into a transformer or a coil, the collapsing magnetic field creates voltage spikes, a diode can be used to rectify this output.
Nixies don't need a clean signal, so that's not an unconvenient if the frequency of the step up transformer ia high enough.

So help me out here guys. I have recently fell in love with electronics and it's a fun hobby.

I am currently working on a small project. I have two 12W square LED downlights and I want them to turn on at night and off at dawn. I am not good enough to design the whole thing myself but I found pic related. It's one buck. It's a "dark sensor". I guess if I connect that to 5A AC relay, I can achieve what I want or there's something I should know?

>>798324
Oh neat. Thanks

>>798328

That seems to be an OP amp acting as a comparator with a transistor at the output of that OP amp (because OP amps can't nornally exceed 20mA) .
One input pin of the comparator is fed by a voltage divider made with two resistors and the other voltage divider by a resistor and the light sensor (which is another kind of resistor) when the light is down resistance decreases, the voltage on the divider of the sensor probably increases, superaring the fixed voltage of the other voltage divider and triggerimg the comparator.

If I haven't made myself clear search for:
Voltage divider
Op Amp
Op Amp acting as a comparator
Transistor (if you don't know about them yet)

There is also seems to be a variable resistor that allows to choose the level light at which the OP is triggered. To do this you just it to a voltage divider, the fixed for example, to choose at which voltage (coming from the sensor divider) the OP will trigger.

>>798328
that would work but you're gonna need a seperate 12vdc supply to run it. easier to get one of these and wire in the leds where the screw-in bulb goes.

>>798328

that would work but you're gonna need a seperate 12vdc supply to run it. easier to get one of these and wire in the leds where the screw-in bulb goes.

>>798328

actually this would be a really easy first project you should build it

you really don't need a comparator or anything that fancy a transistor and a few resistors will do.

>>798387
Wouldn't the 2222 be wasting energy until the current though the collector reaches the switching current of the relay? I guess comparator would be more efficient.

Pic related must be a very similar circuit to this >>798328

>>798392
Yes, but in normal twilight switch use this wasted power is pretty small in comparison to the overall power consumption during an average day.

What are those weird copper shapes on this PCB i marked with a red circle? Is that some high frequency stuff?

>>798410
Yes, it is high frequency stuff. The odd shaped features act as components (eg, attenuators, phase shiftors, resonators etc.) for high frequency signals. Google Microstrip for more detail!

>>798410
top left: bandpass filter
sectors: short circuits to ground (for microwaves, open for DC)
bottom right: bandpass filter
middle: possibly impedance matching circuits

Or not, this shit isn't really my stuff.

>>794557
>>796548
Rolling both just for fun.

>>794223

No you fucking didn't i've seen that before on /g/

>>798539
I've seen it too, I don't remember what was the post about though. I don't think it's worth to mention,

>>796888
Valid sentiment, shit way of stating it/applying it.
If you're busy all of the time pursuing your dream or welfare then sure, whatever. I bet you waste a fair bit of time like the rest of us in ways far less practical than the one he suggested.

>>798544
>>798539

I posted this on /g/ in the thread that said "what are you using yours for? I'm using mine as a paperweight" after i posted this here you cuck.

>>795497
> Unfortunately, Toronto has a sad lack of electrical equipment sources
Sayal is pretty good.
Active Surplus is on Queen street east of Spadina and is based as fuck.

I don't understand capacitors. Why do people use them and when will I have to use one? Can someone help?

>>798690
To make or smooth out a ripple.

>>798691
> this simplistic rubbish

Think of capacitors as reserve tanks, capable of storing a electric charge (or potential). A fairly common analogy is that of a tube with a rubber membrane in the middle. The more electrons you cram into the tube, the more the membrane stretches (the greater the electrical potential that is built). When the electron flow is ceased, the membrane snaps back, dumping the electrons back out (potential returns to zero). There are many types but they all rely on the accumulation of electrons on one of their two plates, in this way, they store the electrons that I referred to in the tube analogy.

They are used in oscillators, for signal coupling, filtering and yes, smoothing DC.

>>798694
What are the safe capacitor ranges? From how many farads? The ones that don't explode?

>>798695
> What are the safe capacitor ranges?
Depends on the device you building, and how much power its expected to manage

> From how many farads?
As above.

> The ones that don't explode?
The ones that fit the criteria defined above.

TL;DR, It's entirely application specific.

>>798694
How are they used though? How do they smooth DC?
How about transistors? I dont get what makes them so revolutionary.

>>798651
Ive actually been to active surplus but couldn't find the stuff I needed. Plus their prices are pretty high. Still on the lookout for the flux and a wick as well now.

>>798715
How do they smooth DC?
Capacitors can save charges and release them when it's needed. When a voltage spike occurs, the capacitor will suck that charge in, when the negative part of the spike comes the capacitor will release that charge, smoothing the wave. The bigger the capacitor is the more ripple they can take during more time. It's like saving money, when you have lots of money you save them on a bank (the capacitor) and when you're running low the bank can fill that void so you can keep buying things.

This is only of the uses, they are also a resistor which varies with frequency. You know DC can't pass through a capacitor, but AC can, so as the frequency increases it's logic to think that signal will be favored and will pass though the capacitor. And you just discovered filters!
The inverse happens with inductors. But that's another story.

>How about transistors?
Transistors are the shit because they are like a switch, but they're not mechanical, you can tell a transistor to switch two transistors and those two switch another two and so on... without any mechanical elements. These switches happen to be very sensitive too, so with a little input you can make everything work, amplifying signals... A combination of resistors, capacitors and other elements gives them special configurations that are capable of many things, from counting to 10 to oscillating millions of times per second. This had to done with vacuum tubes before, which were humongous compared to transistors, that's why we've jumped to black and white TVs to smartphones that vastly exceed the computing power of the best supercomputers made a few decades ago. Thus main advantage of the transistors is their size, you can fit millions in a silicon chip because they are literally "printed" using lithography, you can't just print millions of vacuum valves in a finger nail!

>>798715
Transistors can be grouped together in a very small space, this is what the average digital clock would look like if the transistors, resistors... couldn't be fit into a single silicon chip.

>>798724
Thanks a lot, man. You explained capacitor very well.

Any ideas on what the red and black cables coming out of the side of this flyback are for? I guess they red is another secondary, but I don't know what the black is for. These cables seem to be in every flyback I have and I haven't figured out what they're for yet.

Hey I've got some of these tp4056 li-ion charge units coming in the mail. They're so bloody cheap I'm going to use them to play around with 18650 I've scrounged from old laptops. Anyway the units charge at 1A default but I've got some 5v solar panels that put out about .5A max does any know if this will be sufficient to allow charging(albeit at a slower rate of course)?

>>798742
parallel the solar panels

>>798726
>>798724
Thank you for the explanation.

>>798743
I thought about that but I on;y got the one kinda of strapped for cash don't want to buy another one for a one off project.

Well..

We hit the bump limit.

About time for a new thread then, so before we make one let's try to fix up the OP.

>>798822
super impose a cat head over a bbc, who cares we need an /ohm/

>>798732
I've tested the flyback and they are both outputs, the voltage isn't as high as the main output. I'll probably cut the cables.

7 segment and multiplexing question

its an arduino project using: http://sim.marebakken.com/SevenSeg.pdf

I have a 4 digit seven seg common anode display and the application intended requires switching between several different modes of both refresh rate and duty cycle. I'm pleased with its current display performance however...

My question is If I decided to add more displays through mx'ing would I lose any performance or brightness quality? I understand the delays and interrupts are minuscule but I don't know how much they affect the project (its for his resolution tachometers).

I know thread is at bump limit but it will still be around for a week.

Would this circuit work as a power supply short circuit protection?

>>795284

https://www.youtube.com/watch?v=vIT4ra6Mo0s

>>795323

This is probably the video series you're thinking of.

So, /ohm/

Decided to take on the Home Made Power Supply project.

And now I'm at an impasse.

Do I go dual-rail adjustable with 2 LM317's?

Or do I go tri-rail fixed with a 7805, 7833, and 7812?

I'm mostly an embedded microcontroller guy, so I will largely only need 3.3V and 5V for awhile, but planning for the future I can see the argument where testing my circuits for low-voltage situations would be good.

What say you, /ohm/? Convince me one way or the other.

Pic related, it's the bare beginnings of the design, which I may scrap.

>>799197
quickest way is to try it and see if its acceptable.
you don't need to add te other display in just simulate multiplexing them in software to see how the 4 digits you have look.
you can always increase the supply voltage to your segments to make them brighter and compensate the off time.
leds are damaged by overheating, if they are on for small amounts of time like this you can run them at >rated constant on power and it all averages out fine.