/diy/ - Do It Yourself

I'm having some issues with my oscilloscope. First and foremost when using the scope with DC coupling set the waveform shows a DC offset when there isn't any. I have the scope hooked up to the probe adjust putting in a 500mV p-p square wave. DC coupled should show the exact same waveform as AC coupled in this case but it doesn't. It's offset -250mV and it shouldn't be. I don't know why.

I'm also having some CRT flickering and the waveform likes to jitter left and right a tiny amount every now and then as well.

See related webm, it shows off all of the problems. Is there anything I can do or do I have to start looking for a new scope again? I'm kind of new to this stuff so forgive me if I'm overlooking something obvious.

>>859961
Best advice it to only clean and check connections. You could re-seat any socketed devices. Get Service and User manuals. It may have PS voltages printed on the PCB that you could check and adjust on the PSU board. Maybe even check PSU for ripple in case of dying PS Caps. That's as far as I would go without manuals.

Hi /diy/

Does anyone know what's the difference between all these Aoyue soldering stations? Is there some model that is known to be good?

>>859968
>bms module
>battery holder
>she's just making a battery pack
>holding a board with a steel bench vise
>not spare hand
>soldering over that beautiful wooden table
>the shit that flew when my dad caught me doing shit like that
>dat nipple in both pics
>nerd trophy

>>859982
Also;
> thumb not on button of solder pump
> pretty sure none of the soldering stations are turned on
> high heel on the bench (why?)

There's a pic that floats around /o/ with a chick who appears to be getting ready to change a tyre by undoing the lug nuts with an open ended spanner. This reminds me of that, staged as fuck.

>>859987
>> high heel on the bench (why?)
because she might have been gluing it earlier?
> pretty sure none of the soldering stations are turned on
except for the left one
> thumb not on button of solder pump
seriously?

I think you all are trying to nibble too much

>>859987
the solder station is switchedo n. maybe you are looking at the bench power supply?
and her thumb isnt on the trigger because it doesnt work like that. its a small shitty solder pump that looks like you prime it with your thumb and trigger it with your index finger. her thumb isnt over the plunger because its going to pop up when she triggers it.

>>859987
>high heel on the bench (why?)
look at it again

>>859993
is she making some kind of flashy ladyboy shoes?

>>859982
>holding a board with a steel bench vise
>not spare hand
There's a 3rd hand tool nearby. For desoldering, the board really needs to be tight down since you're bearing down with both hands; 3rd hand isn't going to cut it. I'd do same

>>soldering over that beautiful wooden table
>>the shit that flew when my dad caught me doing shit like that
Depends. Guys at my shop had those tabletops and would drop short blocks on them and drag around. Obv pretty dinged up. That said, she's actually laid out a mat protector over top (it's a fabric cutting surface, IMHO worth more than table top finish, but that's me.)

>>dat nipple in both pics
>>nerd trophy
Yup. Nothing wrong with that.

>>859981
Aoyue also seems to have some hot-air+soldering stations on the cheap, are those worse than their pure soldering stations?

>>859982
great derail mate

>>859993
The hell is that?

>>860023
see >>859995
leds in the shoes.

>>859995
>>860023
I don't know, but that shoe has wires in it and that's enough reason to have it on the bench.

>>859982
>>859987
>waa! a women doing things!

Can you fuck off back to Tumblr? The adults are talking.

>>859982

she's using some type of ESD / cutting mat so the poor table is fine

>>859968
where do i get a waifu like this?,

http://sexycyborg.imgur.com/

>>859981
If you click on "more details" doesn't it tell you? The 936 is the "classic" model, but from experience underpowered (the temp regulation isn't that good). The 936A is higher-power (60W vs 35W).

Only a couple more months until our one year anniversary!

They said we wouldn't make it even a couple weeks. Look at us now, almost a full year.

Proud of you, /ohm/!

>>860082
Good luck, i'm recovering from my third crush, who turned out to be lesbian. I will NEVER date a girl because of a technical or other masculine interest in common. It may come as a bonus in the future. But trust me. don't go around looking for these girls :(

>>860181
I can't even find a woman thats worth two shits let alone one with a brain. A woman with values is a unicorn, a woman with values and a brain is literally unheard of. Everyone I meet just wants to party, drink and fuck. Dark times.

>mfw when she has 100x better equipment than me
forever ZD99
forever 3rd world tier
oh well, at least tips are cheap ($1/piece)

>>859954
Hi all,

So I bought one of these for a dash cam.

A wire got ripped open and I think it blew a fuse when it shorted. I didn't know what fuse rating it was, so I replaced it with a 5 amp fuse. That blew too.

So I looked up the fuse ratings and my bike has a headlight fuse needs a 15amp fuse.

However, I took the little box apart. It is supposed to step down 12v to 5v/1.5 amps.

So shouldn't the 5a fuse have been enough?

I check the continuity, and the continuity is fine. Then I check positive continuity to negative (should be none) and it has continuity! wtf. So I tried tracing it down, and this little box has continuity between the positive and negative.

It connects directly to my license plate lights as I have none. So can I just hardwire it from my license plate lights, all the way to the usb connection that goes to the dash cam? Or do I need this box?

Why would there be continuity coming from this circuit? There shouldn't be any right?

>>860223
The converter (alone) should never blow 5A fuse, if max output current is 1,5A, then it (under max load) will take 1A tops @12-15V input. You probably blew it, if there is a short between input leads. Hard to tell if the repair is possible, but these converters are cheap anyways.

>>859993
>she is planning to haxor from the rich at some fancy party with her shoe.

I doubt it, since its clear someone would see it.

>>859954
>>859982
>>859987
>>860023
This is what she made.
https://www.reddit.com/r/DIY/comments/3em4ig/sexycyborgs_diy_led_shoes/

>>860343
>You must be 18+ to view this community
whuh

I've been working on this project for a while and it's getting close to being finished. It's a water activated SOS flashing LED rescue light that attaches to a life jacket. They sell similar devices but mine is going to be a fair bit brighter and less prone to accidental activation. Mine also has a switch to turn the lights on so you can use the thing as a wearable flashlight too.

>>860372
You must be 18+ here too.

>>860372

why can't we have attention whores like this on /diy/

>>860430
Aw, that's too bad. Sexy geekgirls are awesome, but that much makeup... uhh... and fake tits? Sad. So very sad (my boner, not her).

>>860430
Maybe you could invite her here in our /ohm/ thread? Link this thread to her.

>>860429
We probably do. But they got dicks instead.

>>860405

I bet that OSHA or something has rules about what kind of safety equipment you would need on a commercial boat and anything you wear would have to be up to code

cool project though

>>860429
Unfortunately, tripfags and namefags have not yet been banned.

>>860372
For a reason: http://i.imgur.com/0PZUBfR.jpg

hey /diy/, how would I go about putting some sort of dimmer on pic related? The lamp itself runs on its own little USB converter box to an inline switch. Would just soldering a potentiometer in series work? or would there be more to it?

>>860429
Thank Mr Skeltal

>>860509
A potentiometer in series would burn since I assume the current can go up to 500mA.
Things you could try:
· Get a higher power pot like: http://img.directindustry.com/images_di/photo-g/wire-wound-potentiometer-cement-coated-62485-2349371.jpg
· A power transistor with a potentiometer to the base (Remove RE, substitute the LED by your lamp) (simple and easy)
· A CMOS 555 set as a PWM regulator (not as easy but very effective and efficient)
· Voltage regulators like the LM317 (not recommended with voltages so low...)

>>860560
Why is the R2 cut off?

>>860470
We have had femanons modelling diy dresses on here before. That I don't mind but the inevitable always happens before long.

hi, is ut61e still the king of the hill, or is there some new stuff that is worthwhile?

its a potentiometer with one end and the wiper used

>>860476
I'm just making it to teach myself some stuff. I race sailboats in the evenings so the idea popped into my head. I figure it also might be useful to stick in my portfolio of projects to show future employers I did during my education.

>>859961
>I'm having some issues with my oscilloscope. First and foremost when using the scope with DC coupling set the waveform shows a DC offset when there isn't any. I have the scope hooked up to the probe adjust putting in a 500mV p-p square wave. DC coupled should show the exact same waveform as AC coupled in this case but it doesn't. It's offset -250mV and it shouldn't be. I don't know why.

I'd throw that thing away cause you just don't know how a scope works.

>>860485
She must really be proud of her body if she shared the 3d model for free.

>>859968
that nipple

>>860429
Girl needs to eat a god damn cheeseburger. Ain't nothing to hold onto besides her tits and head.

>>860082
Where do I get a resistor like that?

>>860798
>resistor
>implying it's not painted cookie dough with a metal shaft shoved through the middle

>>860798
It's some kind of a joke he probably made himself. Even if there were some ungodly reason to need a resistor that big (high wattage), it wouldn't be shaped like that.

>>860787
http://pastebin.com/3B86VBZA
>Hi! You’re here because you said something about my weight.

>>860841
What the fuck

>>860681
its a potentiometer.

>>860841

writing this probably took as more effort as those led shoes

>>860711

it's a very nice multimeter for it's price

>>860843
>>860858
>>860858
>writing this probably took as more effort as those led shoes

Yes but probably takes less time than explaining it every time to every retard on the internet.

>>860748
This.
This is the exact reason i always print my name on the silkscreen for every pcb i manufactured/ordered but with every new project the older one feels too inferior to actually be presented.
Anyone has actually shown off his or her work during a job interview as an EE or similar in here?

>>860872

>thinking you have to explain yourself on 4chan

So what, you're cool with being objectified. But an off hand comment about someone else's preference irks you?

>>860872
>look I can connect leds to a battery I'm basically an electrical engineer :^)

>>860751
Well, feel free to explain a bit then. I don't appreciate being written off as a failure when I actively want to learn.

Do they make sockets for these? What's the best way to connect? There are contacts on both sides.

>>860919
Heh, I was googling to see what this connector was and found this.

Anyone got experience with the WT32i bluetooth chip?
I'm trying to interface it with a DAB receiver over I2S, but I am unable to get any sound. And I am in a position where I don't have access to a scope to check what's going on.

I set the in loopback mode where input is I2S and output is the DAC, and have a small speaker connected.
Whenever I set the BT to be I2S slave (since the DAB is the I2S master), I get silence, no matter what settings in data format I set with the PSKEY tool.

Hey /ohm/, I've got a couple of questions as far as home lab setup goes.

I've got a $700 budget to get a basic electronics bench off of the ground. I already have components, some wire, a breadboard, and a broken bench supply that I'm currently fixing. I have a shitty multimeter, but I'm currently in need of:

>A scope (preferrably mixed signal, I want to get into controls stuff, so it'd be helpful to have the logic analyzer for debugging)
>A good multimeter
>A proper soldering station
>A function generator

Is there anything else I'm missing from the list that you'd recommend I add? I'd also like to try and have some cash left over for buying PCBs and project specific parts. My local kijiji (craigslist isn't as popular in Canadaland) is pretty bleak as far as test equipment goes, I've attached a screenshot for reference. I've also tried to contact my university lab to see what they do with old equipment, but no one's gotten back to me.

Thanks

>>860926

Do you have a debugger for the chip?

how do i use a regular gpio pin as a clock signal? i have extra gpio pins and would like to make a second i2c bus. or even spi.

>>861098
The SPI/I2C pins on your (arduino) connect to hardware that accepts a byte and hadle the rest. A generic IO pin can do a serial protocol, but you have to control it from software (bit banging). You can't just send a byte to the hardware UART and let it handle sending out each bit and a clock signal in between, you need to write a function to do that.

>>860882
Yeah, I've been asked to give a presentation of my previous work as part of an on-site interview.

>>861100
its not an arduino its an ft232h breakout board.

i can bit bang. so id be doing like a pwm thing as kind of a faux clock? is that fast enough?

>>861105
> is that fast enough?
Depends on the application and any funny business in the chips you're controlling.
With I2C and SPI there isn't a minnimum speed. Data input to slaves is controlled by the clock signal of the master (your bit banging).

>>861105
Adding a multiplexer controlled by leftover GPIO pins is the best option if you need another high speed (UART hardware controlled) I2C/SPI bus. You can put every data line in parallel, but control which chips take in that data by multiplexing the clock.

Ok, very stupid question inbound
If I have some 3V LEDs and a 3V power source (2x AA batteries) I don't have to put series resistors, right? I can just connect them in parallel and they'll work normally?

>>861151

the only time you wire LEDs straight to the batteries are when the batteries are tiny coin cells which are self current limiting. if you use AAs for example, they're gonna be 1.7V when new, so they may damage the LEDs.

>>861158
Wait, a quick calculation shows 4 LEDs at 0,02A (20mA) each would require a 20Ohm each in parallel or a 5Ohm series resistor to dissipate the extra 0V4 (400mV)
Can I avoid using it or would the LEDs degrade a lot?

>>861159
Also here is the diagram

>>861160
>>861159
Also I just realized the diode would take up 1V and make the whole thing not work, I'll just have to be careful and avoid blowing stuff up with the electrolytic

>>861159
Depends on your definition of "a lot". That 400mV overvoltage might run them at 2-3 times higher power than their maximum rating is and you can expect that to shorten their life more than 2-3 times.
Another thing is that normal alkaline battery's voltage drops quickly. Half-charge voltage is something like 1.2V and end of life voltage 0.8-0.9V, depending on source. Your LED will utilize only a tiny fraction of the total charge.
If your LEDs are white, their color also tends to change somewhat when you wary current.

>>860882
Having a portfolio is always a good idea.

>>860882
I have, but I stopped writing my name on my work ages ago.

>>861163
I'm putting in a 10Ohm resistor for good measure and fuck it

>>859954
>http://sexycyborg.imgur.com/

is the girl in OP image.

Your welcome.

>>861355
Already been mentioned a couple of times in the thread.

>>861355
>he doesn't read the entire thread before posting

Please go back to reddit

>>861421
>im too lazy to read the entire thread

oh well.

I guess this would be the best place to ask a simple electrical question. I have alot of experience fabricating simple metal and wood parts for projects but I am pretty clueless when it comes to electricity. I need to attach a small air pump to a small 12v 5ah battery for the purposes of blowing up many balloons where there is no power source. Portability is important so what is the simplest way to get a few hours of operation?

>>861521
That air pump is meant for 120vAC, so you'll need an inverter to run it from a 12vDC battery. That'll cost more than the battery and pump did. You're better off finding a 12vDC pump, or swapping out the motor in the one you've got.

>>861538
> That'll cost more than the battery and pump did.

not necessarily. the hardware store i visit every week sells 75W converters for about $20, but they go on sale like every 3 months for $12. plus i got a couple more at the thrift store for around $5, a 100W and a 150W.

as for batteries, i'd take along several rechargeable units: 12V NiMh from my drill, 11.1V LiPo from my old laptop, 12V Nicad pack from my portable DVD player, and 12V 7Ah SLA cell from an alarm system.

>>861538
> That'll cost more than the battery and pump did.

not necessarily. the hardware store i visit every week sells 75W converters for about $20, but they go on sale like every 3 months for $12. plus i got a couple more at the thrift store for around $5, a 100W and a 150W.

as for batteries, i'd take along several rechargeable units: 12V NiMh from my drill, 11.1V LiPo from my old laptop, 12V Nicad pack from my portable DVD player, and 12V 7Ah SLA cell from an alarm system.

the trick is to calculate estimated current consumption, multiplied by estimated time to get a Ah rating, then take double that. or if you have a car, then just use a lighter plug, and dont worry about Ah ratings.

>>861557
When you are bumping up the voltage from 12v to 120v the inverter needs to trade amperage for voltage
A 1 amp 120v motor will be drawing 10 amps off the battery
Also I dont think that pump would be able to push the pressure you need to blow up a balloon.

>>861202

10 ohms is a good compromise. but there's no need for that cap since battery voltage is already about as smooth as it gets.

>>861561
There's no need for a cap in a simple battery powered flashlight, but there are a lot of cases where you would use one with a battery. They have internal resistance, so something that draws a big spike of current out of them will cause the voltage to drop temporarily.

Well /ohm/, I've finally setup my workbench in my dorm.
How'd I do?

Also, what's the best way to organize components in a tight space? I've just been leaving them on PCBs I salvage and leaving the PCB in a box until I need a part from them. Dunno if that's the best way to handle it though.

>>861624
Leaving them on PCBs seems like an awful idea, everytime i would want to build something i would freak out over desoldering everything first.
Keep an eye out for cheap components online or just desolder everything and get rid of these boards.

Hey guys, I'm upgrading my psu benchtop power supply today, now I've found out the heatsink on the high voltage part of the board gets quite hot, even with the power off (green wire disconnected).

Is this part of a normal stand-by operation or should I suspect a short?
the rest of the circuit works just fine.

>>861629
I'd be inclined to agree, pic related is my junk boards. Having not touched them in over two years because I generally need to buy application specific logic per project (which means I'm on a component suppliers website, which mean's i'm usually throwing in a $5 grab bag of mixed components of [insert variety here] while I'm there) I have done a basic strip (mainly logic) before I toss them. Just not worth the space now that I have incrementally stocked myself up on all the passives and transistors I could possibly need. Plus you never know, that regulator you just pulled might be the reason the device went flakey in the first place. Last thing you want to be doing is inadvertently adding bugs into your prototypes.

>>>861634
> upgraded my power supply unit benchtop power supply
Does it need a PIN number to operate it? Meanwhile, that tells us nothing. Is it a switchmode power supply? Linear? Does the green wire cut AC load to the unit or is it a soft start/stop switch? Based on your info, my answer is "yes".

>>861641
>that tells us nothing
He's using a PC PSU.

>>861634
Is the on off switch directly connected to the AC of the mains?? Because if that is true you would need to get a 4 poled switch because there would still be electricity going in your circuit through the other ac wire coming from the mains.

That would atleast explain why it still gets warm.

Hey guys 2 things, Any way to make an audio display board easier then this?
Also anyone had experiance building their own spot welder with a MOT or better off with a $1200 ebay jobbie?

>>861667
> SchematicsForAnts.jog

>>861671
>SchematicsForAnts.jog

Sorry about that lol.

>>861677
why is that a display board? all that is in that schematic are relays

>>861682
Ever seen the racks they use to display car stereo's? the switches control the relays to allow the power or audio to pass to different headunits, speakers and amplifiers.

>>861682
oooooooooooh, you mean a car stereo equipment demo board (had to go find the site you took that from).

>>861685
Sorry again, yeah one of those, I am going to be building one for my shop but I dont want to build a 30 relay mess, it is easy to do but its an electronics store and I would love to be able to show off an arduino system within it. obviously the relay system would have to stay but i'm thinking along the lines of an linux os running a graphical web page to control it... or more simply re-inventing the wheel. also 5 points for beige.

>>861685
I remember wiring up things in those. We had to mod them when stereos started pulling most current from the continuous 12v line rather than the ACC line.

You could reduce the relay count by heaps if you used these.

http://www.alliedelec.com/images/products/datasheets/bm/MAGNECRAFT/70184965.pdf

>>861719
HeadUnits use to use solid acc? That sounds fun. Yeah I had looked at multirelays but the biggest thing is control.

probably best (and eassiest) to keep the relay section for the amp/power and speakers switching (it'll be a pain to use solidstate devices like mosfets). so that leaves just the control section but thats only a few more relays so easier just to use the whole thing as diagrammed. also this thing won't let you select headend units. it only has amp-to-speaker sections.
if you really want to micro it, just replace the buttons with 3.3v/5v relays and setup the hold/release via software (using a nice graphical touch screen).

>>861634

a PC power supply should'nt get the slightest bit hot when sleeping. yours is sick.

>>861691

yeah, but using an arduino, or a web app, does not somehow remove the need to switch music on/off to each speaker. and relays are the most common sense way to do that.

also, there's some seriously-retarded shit going on with that schematic:
- why not use double-pole relays so you only have to use half as many?
- why do you even need relays? you could just use double-pole switches. if you need to ensure that there are not too many speakers connected simultaneously, you could use a ganged pusbutton arrangement to select 1 of many.

>>861742
>relays are the most common sense way to do that

Wouldn't putting the audio through an analog multiplexer like the CD4051 be way easier and less expensive than all those relays? You can keep adding them to build a mux much bigger than the eight outputs of one chip. Audio through a mercury free relay makes a load popping noise when you switch them, and those are the only type that can still legally be sold. You also need to add a transistor and snubber diode to drive the coils from a TTL output.

>>861782
> putting the audio through an analog multiplexer like the CD4051

won't be able to handle the outputs from the power amps.

I use ziploc bags to sort all my components
You can find them in the office supplies section for dirt cheap

>>862026
>>861624

>>861725
>use to use solid acc?

You know how you have continuous power and switched, normally yellow and red. The older units drew most power via the red wire with the yellow only keeping the preset memory and clock only. These days the red wire is pretty much just an internal switching trigger much like they do on car amps and the main current is pulled via yellow.

Guys, CS student here. I learned how to solder today, built some kits. It was fun, but now I want to get deeper into electronics. I thought about building an ALU with logical gates (I don't wanna go transistor-low).

Is there any other cool project you guys think is fine for a beginner? I need to do something.

>>862052
Download Make:Electronics by Chrles Platt .pdf for beginner projects

or read the pastebin from the OP

http://pastebin.com/9UgLjyND

>>861634
5vsb is, in ATX 2.01, only required to supply 10mA.

If you're loading it with ~550 ohms, you're running it at 91% capacity, *all the time*.

>>861660
>>861641
If you don't know how ATX works, perhaps instead of speculate or condescend, maybe you should google?

>>861634
The anode/cathode of the LED is unspecified. Why?

>>862052
In my CS course, we built a mouse driver in hardware and hooked it to an oscilloscope. Fun, simple project, with obvious discrete stages that can be unit tested (optical-encoder interpreter, counters, DACs).

You'll need an Atari/Amiga mouse, though: PS/2 mice do all this internally and communicate with the PC at a higher level of abstraction. Atari/Amiga mice give you the raw output from the buttons and the optical encoders over a parallel cable.

>>862062
I would assume because it's irrelevant and blatantly obvious?

>>861634
Also note that PWR_OK is not actually specified to supply power at all. It's a logic signal.

You should really be using it to, say, switch +5V through transistor.

>>862052
I started a company making guitar pedals. Would you ever be interested in taking an online course that teaches basic electronics and soldering, and then sends you kits to build along with the video instructions?

>>862026
>>861624

>>862074
Is that... a rare Pepe?

>>862098
the only one I have, but it was so rare I had to catch it

You should add W2AEW's channel to the pastebin.

https://www.youtube.com/user/w2aew

He's a ham (obviously) and his day job is at Tektronics I think. He's an applications engineer there I think. He has a plethora of RF/signals/analog stuff that is pretty darn interesting.

>>862052
search ebay for solderless breadboards and "logic gate dip", buy a bunch of what you need, and hook it all up

>>860181
Are you an electrician or an engineer

>>860895
It's embarrassing but I felt this way the first time I made my own working circuit with a switch to turn an LED on and off

>>861742
>ganged push button arrangement

That is what our comparator used.

Everytime I make this circuit my pots burn out? I even had it working then randomly one day they'll combust. From my understanding
Pin 1 is output
Pin 2 is volts input (9V is what I'm using)
Pin 3 is ground

>>862364
Using pic related

>>862365
What's the power rating

>>862364
Wrong pic?

>>862372

>Pin 1 is output
>Pin 2 is volts input (9V is what I'm using)
>Pin 3 is ground

yeah, thats why its burning.
Pin 1 is 9V
Pin 2 is to 555
Pin 3 is ground

>>862382

555 timers drawing more than 1/4watt through these pots? something is fishy

>>862395
wait, why is anything on the pot connected to ground? that's not on the schematic at all

basically, when you turn the pot all the way off, pin 2 (9V) is shorted to pin 3 (ground), and I shouldn't have to tell you that this is bad news

>>862364

>>862400

what did you use to make this? I could really use a program like this

does it do perfboard too?

>>862401

>>862403
https://www.youtube.com/watch?v=E2VnkwqoN4U

>>862408
https://code.google.com/p/diy-layout-creator/

>>862408
>>862409
thanks!

I'm sick of using Eagle for everything

Is building an audio amp primarily out of op amps a bad idea? Is there any reason I can't just stick a single high-current op amp in front of a class B output stage instead of making the whole thing out of discrete transistors?

>>862436
Many IC audio amplifiers are basically high-power opamps. And yes, using an opamp to drive a class B or AB output stage is a common practice.
A carefully designed discrete transistor amplifier can have better performance than opamp-based designs. However, many full discrete amplifier designs are just old, from the era when using opamps didn't make that much sense.
The amplifier in your pic (assuming it's what I think it is) is accompanied with a series of articles to explain the design choices.

>>862439
it's from a douglas self book

>>862444
The article series was also written by him.
In any case, no need to guess why the amp is designed the way it is.

k folks
finally bought all my parts
will prolly make my own thread when I really get to building it

>>859961
First of all, are you sure there shouldn't be an offset? You're connected to the calibration output, it could be that it does have that -250mV offset.
What you should do is get the manual for your scope and go through the calibration procedure for it. That may help, it may not, but it's good to do regardless. It might help determine if you really have an offset problem.

>>862444
[x] genuflect

>>862733
Don't do that. Just post updates here.

What are you making anyway

>>862758
Power amplifier based on the McIntosh MC2300.
Two 150W channels, but easily convertible to a single 300W channel.

>>862771

>no annotations

motherfucker how do you even keep track of anything did you do this in paint or something

>>862788

or autocad looks like that

>>862788
>>862789
using gEDA

Why on earth would you jump to the conclusion that I have no other info or pictures or notes based on this one post?
I just like cleaned schematics like this because they look nicer and are easier to read.

>>862792
gEDA is so shit, man


I'd rather draw my schematics by hand, then waste time breadboarding and testing /debugging with an oscope that use that shit program

>>862796
ok.jpg
It's perfectly fine and you're a faggot.
All that really matters though is that it respects my freedom.

>>862807

Nigga just use KiCad then; it's released under GNU GPL free as in freedom license

>>862820
Nice.
I'd never done cadshit before and prolly won't very often.
But thank you, I'll check it out.

>>862822

Look up a guide to get started; you'll likely need one if you haven't worked in a similar environment before and it should save you time. If you don't need to do boards you can just learn how to make component symbols and work in EEschema and that should cover you fairly well.

I'm making a high voltage PSU and I plan to parallel this three IRF540N MOSFETS to replace a IRFP260, in parallel they should have a lower resistance, higher current handling and thermal dissipation.
Do I just have to solder all the drains and the sources together? For the gates I thought about putting a 10Ohm resistor in each one. Is it this simple?
Sorry for the stupid question, I've never done it before and I feel like missing something.

>>862844
yes, you've got it right. You can just parallel the drains and sources but each gate must have its own resistor.

>>862820
>KiCad
Whelp..

>>862889
> forgetting pic related
My fail is clearly seeping into their webservers..

thought I'd share link of my last project
https://www.youtube.com/watch?v=nNOy1-V9KUI

Can you kind people tell me how to fix my amp? I think the problem is that the bias switch on the back was set to EL84 power tubes, and the tubes inside are 6L6GCs. I never touched that switch, so the dummy who used to own it must have done it. I got the head and matching 4x12 cabinet dirt cheap, anyway.

It says on the back of the amp that "power tube failure may result" if the bias is set incorrectly. I just need a new set of power tubes, right? There's 4 6L6GC power tubes and 5 12AX7 preamp tubes. I'm not sure if I have to replace the 12AX7s.

Pic related, it's a Carvin Valve Master. 100 watts of all-tube pwnage.

>>862986
I tried changing the fuse (which looked burnt out), but I was only able to turn the amp on momentarily. Once I turned it off, I couldn't turn it back on. Someone told me it was the transformer, and that it would be an expensive repair. I almost got rid of this thing, but I realized that it might be an easy fix.

Can I replace tubes myself? I've heard that tube amps contain lethal voltage even after they've been unplugged.

>>862986
I'm an amp tech.

Get a new set of power tubes (the 6L6s) The 12AX7s are going to be fine. When you replace the tubes, you should also re-bias. Buy the tubes and just take it to a shop to do (I know thats not in /diy/ spirit, but it'll be cheap anyway... maybe $30)

If you want to test the 12AX7s to make sure they are fine, take a pencil with a rubber eraser, turn the amp on, and very lightly tap the tubes. A bad one will make a rattle that will come through the speaker. Like I said though, the preamp tubes are probably just fine.

>>862988
If a fuse is burnt out, it always means theres something else wrong. Get the new tubes installed and the amp biased, I bet that will clear things up.

If you want to install the tubes yourself, you'll be fine. Just make sure you don't touch anything dangerous in there, the big capacitors can store a decent sized charge. If you decided to go this route, look up how to discharge capacitors (it involves buying a high wattage, low value resistor and then using that to ground the positive side of the cap for a split second).

Again, if you aren't comfortable with this at all, just take it to a pro. A re-bias is pretty routine and cheap.

>>862889
Yeah idk what happened but it's back up now

>be me
>transfer from CC to University
>Be EE student
>teach myself to program/use atmel AVR chips
>register for classes
>Look through the intro to engineering syllabus
>see pic related
>FUUUUUUUUUUUUUUUUUUUUUUUUUUUUU

I get that meme board is easy to use and thus easy to teach a class with but come on, what is the point of using this toy in a university class? I mean, kids play with these things.

>>863018
Unfortunately it's because not a lot of people do this stuff on their own time. Our uni started us on pics but some of the latter classes abstracted to arduinos to simplify things and make them go faster for teaching. I'm a mechanical engineer and regularly work with pics for stuff already in production but often use arduinos for quick and dirty proof of concept prototypes. They have their uses but a lot of the problems with production models I couldn't have solved if I hadn't had the first class with pics so I'm glad I got that exposure.

>>862074
Wasn't that what Contextual Electronics was supposed to be?

So i have these Class D amplifier modules and i want to make an amplifier for my electret microphone capsule. I am pretty sure this will work with a low-pass filter on the output for lower frequencies.
Where the power output is should be a small voltage regulator circuit so i could control the amplifieing factor with a pot, my conceirn is that if i change the voltage the whole amplifier circuit will be fucked up because of increased current.

Will it fuck up the amplifier or will it work, i think there is a possibility because class d amplifiers are pwm based?!

I know there are easier ways to do this but i have these modules laying around.

Post book collections

Short question here, can I simply connect 7 5V power supplies in parallel in order to make things work that need more current than one power supply can provide? Example:
Seven 5V/0.5A supplies -> One 5V/3.5A power supply than I can connect to my smartphone, for example

>>863151
Are digital ones allowed?
Just started looking up stuff and this is pretty much from the OP

>>863178
Sure. I didn't post my digital books cause I'm lazy, but they're still books

>>863078
Yeah pretty much, except I'd give away a lot more free content, and try to focus on projects that made sound or did audio signal processing.

>>863169
If it's just DC, you CAN do that; but what the fuck, seven? Why?

>>863169
Wasn't there the rule to never connect DC sources in parallel?

>>863198
if they are for sure exactly the same potential, it can help you provide more current if necessary...
... but how often do you get two batteries at exactly the same potential if they aren't fancy industrial ones?

>>863196
I'm actually thinking more about 14 now. I just got a bunch of those solar panel USB charger that at max provide like 100mA.

>>863198
Dunno, that's why I'm asking

>>863204
You'd also require a very good capacitor or a shitload of small ones since you're working with an unstable source
Also where the shit did you get 14 solar panels

>>863212
Work. I took them all from the "broken shit"-shelf at work after asking my boss if that's fine. But only about 10% of things are actually broken, so I guess it's the same for the solarpanels.
I also have 29 7-USB-hubs. Dunno what to do with them.

>>863215
Mail me one or 2

Anyone know of a microcontroller with the following specs?:
>192 outputs (LEDs)
>128 digital inputs
>64 analog inputs

>>862995
Thank you so much. I found out how to change tubes, and all I need to do to re-bias the amp is flip a switch. Now I just need to buy the tubes, which brings me to another question:

Can I just use 2 tubes? There's a 50/100 watt switch on the back of the amp. The 50 watt setting uses 2 tubes. I don't want to spend $40 on two tubes I don't need. 50 watts is plenty. Is there a certain way I have to arrange them? I was just going to put 2 side by side, with 2 empty slots.

>>863169
> can I simply connect 7 5V power supplies in parallel

sure, but you need to add a diode in series with each one so that they dont waste a lot of power dumping current into each other. if the loss of 0.7V across each diode is a problem, there's a way to use a FET to make a no-voltage-drop diode. see RasPi2 schematic as one example.

>>863290
I don't think you're gonna find such a huge uC.
Try using multiple smaller controllers, maybe use serial communication between them.

Alternatively, you could probably design a much more efficient system using some sort of multiplexing / demultiplexing system that assigns addresses to each of your outputs and/or inputs and uses a single micro-controller with 6 or 8 ports to control them.

>>863290
Something like Freescale's MPC5554 has 40 analog inputs, but that is not a sensible way to do things (I'm guessing you're not too keen on 416-pin BGA chips that cost over $50 each, not to mention the expensive development tools you need).

Using multiplexers, switches and latches you can vastly reduce the number of pins needed.

>>863329
Thanks anon, that's what I was looking for

>>862860
Thanks, I got it working https://www.youtube.com/watch?v=Mx4396J4d9g

>>863290
or use several spi/i2c multichannel ADCs, such as these: http://www.maximintegrated.com/en/products/analog/data-converters/analog-to-digital-converters/MAX1257.html

>>862400
is R1 a 4.7 Kohm resistor? or 47?

Thanks again for uploading these, going to do >>862401 once I can get the basic one down.

>>862401
Is there a more proper schematic for that? jesus it looks like a whirligig spaghetti.

>>863728
4.7k. The decimal is replaced with the unit indicator to avoid confusion or misinterpretation on poorly printed or reproduced schematics.

100 = 100 ohms
2k2 = 2.2k ohms
1M2 = 1.2M ohms

>>862400
Can anyone confirm if this would actually work?

Having no success (8ohm speaker instead of jack)

Finished my PSU, and my first real project.
How's it look? I used an old KVM switch as my chasis. The only tools I had to cut the opens with was tinsnips so it's kinda sloppy.

>>863819
Looks nice, don't forget to ground the chasis if the mains go in there too.
Also i can recommend a rotary tool, it makes things easier and doesn't even have to be a dremel to work fine.

>>863819

a real craftsman would kill himself before showing that in public. fortunately, it's not too hard to fix with some adhesive vinyl.
- remove all the extra connectors that are not used
- cut a rectangular piece of acetate to cover the front, glue it on. this keeps the vinyl from outlining the holes.
- cover the whole box in a tasteful vinyl pattern. the nice thing about vinyl is that you can bend it around corners, so all your corners look perfect.
- re-install the pot, jacks, etc.

I'd also move the pot to the right-hand side, unless you're a lefty. and put the switch in the back coz it's diconcertingly placed.

>>863756
I've always wondered why they did that. Thanks for the knowledge anon.

>>863819
buy a cheap chinese dremel. they work great.
also why leave all the old plugs in there? just bog and sand with body filler

>>863827
people that generally use PSUs and diy electronics dont give a shit about vinyl.
>>863819
Looks quite decent for a first time project, good job.

>>863827

It looks fine

save the arts and crafts for building other shit, test equipment doesn't have to be pretty

Hey /ohm/, I would like to start making robots, where do you suggest I start?

>>863827
>cover the whole box in a tasteful vinyl pattern.

tasteful vinyl... try the new banana flavor

>>863823
Thanks! I'll look into that

>>863827
>>863832
I'm really low on tools atm. Plus, this is just to get me by for now. It's a linear PSU just to do small projects. Once I get some real tools and maybe a nice case I'll make a switching one as a more permanent solution.

The reason I put the things where they are is because all I had was tinsnips and I had to use whatever hole I could get them in. I don't have any means to fill in the gaps right now so I just left the old VGA and PS2 ports on. Hell, even the pot is held in by one of the PS2 ports flipped backwards and pressed against the back of the pot using some long screws I found in an old tv.

It's very sloppy, but hey it works. I can build basic circuits with it.

>>863947
>Hey /ohm/, I would like to start making robots, where do you suggest I start?

with robots, you always start with the vagina and work outwards.

My Weller wes51 just fell off my table and now its noticeably bending if I apply pressure to the front. It still works fine though but is there anything I can do to really check its okay?

>>863947
>do research on what microcontrollers are.
>order a free sample at Atmel TI or Microchip.
>get a cheap programmer.
>start learning the basics like that.

I can recommend not using arduinos, there is a cheaper way which also is more advanced and you can gain some actual knowledge out of it. After you got that you surely can think of a design for a robot.

>>864140
is the sleeve loose?
try unscrewing it and screwing it back on

>>864184
The sleeve for the iron? It is fine since only station fell and not the iron itself.

>>864190
so what's broken? I thought it the tip that was wiggly

Is it the front panel? I just tested mine and it presses in a little if I press my thumb into it

pics would help

>>864196
Yeah it was the front panel that I was worried about. I guess it's part of the des

>>864204
*design
Also the thing has pretty bad scratch marks now. Guess I can't resell it now

Guys i have a problem, im fixing a electronic stage of a rolling machine and i cant find the equivalent of the A69157 SCR. Ive alredy searched in google and in the ECG equivalence catalog but i dindt find anything. Im Chilean BTW so i dont have so much posiblities down the south here. Do you guys know what equivalent i can use in this case? Photo attached, and sorry if i use a bad english grammar, im not a native speaker.

>>864208
>ECG equivalence catalog

link? this would help me so much

Old school as fuck

there is the reply, im sorry but i use a book edition of the ECG haha

I'm currently attempting to convert an old portable Palm keyboard into a USB keyboard for a computer. I opened up the keyboard and found that the output is serial (TXD and RXD). Is there a way to convert this directly to USB (or PS/2) or do I need some kind of converter?

>>864288
You need a converter, and since you want it to look like a keyboard, a regular serial-to-USB converter won't do. Since USB keyboards usually are low-speed devices, an ATtiny with V-USB ought to do the job.

I am not sure if this is the right thread, but I have a question, is it possible to achieve this?

There has been recent thefts in my area, and I was thinking of doing a "kill switch" sort of way, essentially you turn the key to the on position, but it won't start unless you're on a certain radio station, is that possible? If so, what would I need to achieve this?

>>864208
>A69157
http://www.ebay.com/itm/1pc-A69157-Genuine-TECCOR-TO-220-/181609112351

>>864294
Thanks guy

>>863819
So, uh. You gonna do anything about those pointless VGA and PS/2 inputs, or are you gonna let people plug in their obsolete peripherals and monitors in there?

>>864296
Won't work unless the tuning knob is in certain position? Microswitch and some mechanics + possibly a bigger relay to switch mains current on/off?

>>864296
The simpler solution is an "obvious" kill switch for the ignition, and a much more thoroughly hidden kill switch for the fuel pump. Perp will find the obvious switch which will get the engine turning over, but without knowing of or finding the switch for the fuel pump they will think the car is fucked and move along. Has saved me twice (though the second time the scumfuck took to my dashboard with a hammer or something out of frustration)

>>864313
It's a repurposed case. It used to be a kvm switch. I kinda like the way they look even if they're useless. Taking them out and filling in the gaps wouldn't be worth the effort imo since I'm going to make a switching psu later on or just buy a legit benchtop once I get enough money.
It's more of a temporary solution and also just to say I did it.

>>859954
Would a 100w MOSFET heat up more if it's switching PWM 50 % duty cycle or when it's always on ?
Let's say its switching a 80w load.

>>864349
100W mosfet and 80W load are very different things. Let's say your 100W mosfet has 1 ohm resistance when it's on and you're using it to switch a 80V 1A load. The power dissipation in the mosfet will be 1A^2*1R=1W. On the other hand, if the load is 8V 10A, then the power dissipation will be 100W.
The answer to your actual question depends on switching losses, which are dependent on your switching frequency, rise/fall rates and the reactivity of the load. Assuming reasonably low frequency, decent gate drive and resistive load, 50% PWM heats the mosfet less.

>>864351
>power dissipation can be greater than the power input into the system.
Did you just invent zero point energy?

>>864369
Har har. Explain it better then, if you think it was confusing.

I dont understand this datasheet

are pins 3 and 14 the annode?

http://www.digikey.com/product-detail/en/SA03-11SRWA/754-1454-5-ND/2163717

>>864466
yes

>>864316
I was thinking of that or actual certain radio station.

My idea for a first arduino project is to make an RC car that has a sensor to avoid objects and depending on the direction it goes an LCD screen would print "left" or "right" like a blinker on a car. Is this too advanced for someone with little electronics experience?

>>864757
You should be fine, but do your project in small steps.
Get an LED to blink.
Get an LED to blink when a sensor picks up a wall.
Add an H-bridge IC and control the motors in a simple pattern.
Program the logic to make the car back up and turn when it picks up a wall.

If toy has car-style steering and the front wheels aren't controlled by a servo motor you'll probably need a sensor to tell the arduino the direction they're pointing or it will be very difficult to make it drive in a straight line.

Hi guys, had a very small question. I'm trying to make the circuit in pic related but I could not locate a 500uf capacitor. I found a 470uf 25v one instead. Can I use that?

I'm making a sword from WoW that has runes and shit that light up when the sword is held if that help. Much thanks!

>>864794
That circuit is designed to have the lights fade on when the switch is closed then off again when opened. A 470uF cap will make the fade slightly faster than a 500uF. You can also adjust the fade speed by making the 1k resistors larger.

Whoever drew that circuit didn't put resistors for balancing and current limiting on the parallel LED group. This is not smart.

>>864795
1. Awesome.

2. Crap. could you explain
>Whoever drew that circuit didn't put resistors for balancing and current limiting on the parallel LED group. This is not smart.

What would happen? Is it dangerous? What should I do?

>>864796
When you're putting LEDs in parallel groups like that you want there to be a resistor in each series segment. Without it things usually work okay, but there can be some problems:

It's possible that one of the series segments will have a voltage drop a few millivolts less than the others even if all the LEDs are supposed to be identical. If this happens and you don't have the resistors only that one segment will light up and the rest will be off or very dim.

In your circuit when the transistor is fully saturated it acts as a connection straight to ground so you have 9v running through the LEDs. If you use 3.5V LEDs this means 9v is dropping through a series pair that's only meant to drop 7v. This isn't so far out of spec that they'll die immediately, but you'll shorten their lifespan considerably.

Calculate appropriate series resistors like this.
I_led = individual LED recommended current (amps)
V_led = individual LED recommended voltage drop.

With two LEDs in series the total voltage drop is 2 * V_led. The current is the same as for a single LED. You choose a resistor to make up the difference in voltage drop between the LEDs and power supply by following Ohm's law. With a 9v supply and two 3.5v LEDs in series you need to drop 2v. R = V / I = 2V / I_LED. I_LED current will probably be 20mA to 40mA and specified somewhere by the manufacturer. mA are to amps as mm are to meters.

>>864799
Hmmm. I think I understand. I'm using standard 5mm blue LEDs which is rated to have a 3.4v and a max current of 30mA. So if I understand you correctly, R = 7/30mA yes? Which gives me R = 0.23.

which I'm again guessing should translate to 39 ohm resistors for each pair?

Apologies. I'm trying to understand and I'm very new to this. Thanks for taking the time to educate me.

>>864801
A group of two 3.4v 30mA LEDs will be 6.8v 30mA. You need to convert from milliamps to amps before using Ohm's law (30mA = 0.03A). You want the resistor to drop 2.2v (9v - 6.8v). R = V / I = 2.2v / 0.03A = 66Ω. This is not a standard EIA resistor value. 62Ω or 68Ω are fine.

>>864804
You sir, are awesome. Thank you very much!

Just to be clear, the 62 or 68 ohm resistors should be in series with each pair of LEDs yes?

>>864807
Yes, one resistor on each branch with the LEDs.

>>864351
Thanks. Clears up things a bit more to me.

how does this work /ohm/?

https://www.youtube.com/watch?v=cSwCv9_aC3E

I thought all you would need to charge a capacitor would be a battery

>>864871

if you charge it with a 1.5V battery, you can only charge it to 1.5V but if you use that thing, you can charge it up to 500V, assuming it's rated for it.

Hi /diy/, newfriend here.
Do any of you have any recommended kits or projects that give a rundown of electricity as a whole? I don't think my electronics score on the ASVAB is gonna look too good if I don't do some hands on work. Any recommended advice or projects?

>>864871
The voltage stored in a cap is the voltage used to charge it. The voltage rating of a cap just tells you the max voltage you can use without damaging it.

The circuit in that video is producing a higher voltage. It uses an oscillator to produce a pulsing voltage (AC) which goes to a transformer. Transformers don't work with DC. The capacitor output will be a sin wave which needs to be rectified before charging a cap.

>>864883
* The transformer output will be a sin wave

>>864882
>ASVAB
You'd have to be asleep or clinically retarded to get a bad score. Don't sweat it.

>>864889
I'm not exactly the kind of guy to know what a thermocoupler is but I'll try and keep my composure and try to make the most logical decisions

>>864882
The ASVAB doesn't have a electronics section

Hello I need a nand transistor and a product guide says to get a CD4093UBE but all the transistors online are CD4093BE, CD4093BF, or simply 4093 with no letters following...what are the differences and can I use any of them??

>>865045
The end of the device marking usually (but not always) indicates the package. Read the datasheet.

Would there be any actual brick&mortar stores that sell these http://www.amazon.com/Electrical-Electronic-Installation-Symbols-Template/dp/B0039OGCJW ? I had a professor that used one and it really made all his notes much neater, I'd like one for myself. Alternatively, anywhere that might have them for less than 22 bucks?

>>865048
Thank you, could you tell me what this symbol means inside the block before the logic gate? In other diagrams that symbol is drawn inside the NAND gate...

>>865059
schmitt trigger

>>865061
Thank you very much, by the way RadioShack doesn't carry any of these parts anymore. Could you direct me to a place to get these parts?

>>865063
i dont believe you if you say radioshack isnt carrying 4093, tip117 and 2n2222 transistors anymore...

>>865063
That chip is called a quad NAND schmitt trigger. They're usually drawn a little differently with a single schmitt symbol inside the NAND symbol.

Hunting down a specific chip used in an old book is a pain in the ass. You can use a different quad NAND schmitt IC, two duels, etc. You've just got to pay attention to differences in pin positions.

>>865090
I'm surprised you can't buy 2n222 at Walmart tbh

>>864871
>tfw your video get's posted
As >>864881 said, the voltage of the capacitor will be the voltage of the battery you charge it with, what that device does is it increases the voltage of the battery thanks to a transformer (flyback mode) so you can charge capacitors up to 400V with a 12 volt battery. To achieve this, the transformer primary induces a magnetic field in the core for a brief period of time, this magnetic field then collapses back into electric energy, thanks to the higher number of turns the voltage increases. The signal is rectified to avoid losses and contain the energy inside the capacitors. It also stops automatically when the capacitors are charged to avoid damaging them. >>864883 (Not a sine wave since it's operating in flyback mode, but that's how it works basically.
Here I explain how it works in more detail:
http://www.instructables.com/id/Capacitor-charger-60-400V/?ALLSTEPS
Some more videos about it:
https://www.youtube.com/watch?v=xOMwHEKC-7g
https://www.youtube.com/watch?v=dXQ1lGll2rM

>>864871
https://www.youtube.com/watch?v=wBuXeanEFhY

What's /diy/'s recommended soldering station?

This $10 soldering iron I got from Walmart is a piece of shit, and I need something proper if I'm going to repair motherboards in video game systems (which is what has recently gotten me into the world of soldering in the first place).

I hear that Weller (the "blue" models, not "red") is supposed to be the hot shit, but are there any cheaper alternatives? The WES51 I'm looking at is $100 online, and I'll buy it if I absolutely have to. I'm just looking for a fun hobby so my hands are busy in places other than my penis.

>>865270
there is a trick to that anon. for those super duper tiny traces and pads you need to connect wires to, I use a 3$ pot of solder paste from ebay and 28ga kynar wire. i just strip the wire tip, scoop it through the paste so i get a little blob of paste on the tip then solder that to the board. fucking around with solder wire for traces that small is just too hard.

>>865045
UB = unbuffered, B = buffered.
In practice: B = normal, UB = weird shit, unless it's an inverter for a crystal oscillator. Your circuit is very likely to work with B (BE/BF) version.

>>865270
Take a look at the Hakko FX888D for about the same price, maybe slightly cheaper. It has 5 or 6 temperature presets, temperature readout and heats up alarmingly quickly. Build quality is very nice.

>>865063
Unless you really need the schmitt-ness, get a 74HC00 instead.

>>865288
... or wide supply voltage range.
It's not like 4093 is rare.

Google says he's building pic related. Any 4093, including CD4093BE, will work.

>>865051

you're not likely to find a bricks-and-mortar store selling those plastic templates because no one uses them any more, everyone now using computers instead. if they exist anywhere in town, it would be at the bookstore for a university offering an EE degree, or a technical school.

>>865306
Damn, I wish I had a laser cutter to make one of those.

>>865376
a good vinyl cutter will do

>>865306
y u no PNP transistor tho?

So I'd like to measure temperatures up to 300°C with a sensor, more specifically I'd like to measure the temperature of my oven since it lacks a temperature reading, also it doesn't have a window where I could attach a thermometer. I want the sensor to be inside and the rest outside.
How should I connect the sensor to the rest of the device? I assume if I use normal wiring, the heat would travel along the wire and damage the other components. Do I have to put special components inbetween or just isolate the wires in a special way?
Also if someone has a simpler solution I'm open for ideas

>>865505
K-type thermocouple and a cheap-ass digital thermometer or multimeter.

been wanting to get into modular synth for a bit. taking a break form the tube amp and guitar effect stuff.

just assembled a VCO. this is my first module, just testing at this point.
the waves are all weird, but I'm sure it'll straighten out with adjustments.(many trimpots)

i got the pcb at musicfromouterspace.com

>>865615
Post sound clips

>>865505

no need to reinvent the wheel. you can get a wireless BBQ thermometer for under ... $100 ... yikes! i thought they were cheaper. i got mine new for $4 at the thrift store.

http://www.amazon.ca/Oregon-Scientific-AW129-Wireless-Thermometer/dp/B0006G2WYK

if you have an older oven, not the induction ones, i suppose you can stick the probe down the hole where it vents under one of the burners.

Anyone here know about techparcel.com? Is it legit? Is it worth?

>>865680
also tronclub.com

>>865270
WES51
E
S
5
1

how do I actually learn electronics
I was told using an arduino isnt teaching me real electronics

>>865865
Arduino teaches you how to tinker with microcontroller systems.
See OP's pastebin.

>>865893
All the YouTube channels are really confusing and are taking about shit that goes over my head
Is there anywhere where I can find a list of things a hobby electronics person needs? I have a breadboard, LEDs, wires, push buttons, and some other stuff

>>865903
Oh yeah I have resistors

>>865903
I don't know about the utoob channels, but it lists some beginner-tier books. Of those, at least make:electronics presents a list of stuff you need (to go through the book).
Find some interesting, but not overly complicated project. See what you need to complete it. Buy stuff. LED blinkers are popular beginner projects.

>>865865
I think a regular micro will teach you more than an arduino, but you'll have to buy all the peripherals seperately
I'd reccommend you get some 8-bit micro like the atmega32, a max232 + serial2usb cable, and an analog and a digital sensor of some kind. Once you've implemented all that you'll already have come in touch with serial UART, Analog-Digital Conversion, SPI/I2C, basic Interrupt handling and just general stuff like using control registers

>>865925
Nothing in Arduino stops you from manipulating the MCU control registers directly. UART and interrupts are available without any external stuff, for ADC you need something to measure and for SPI/IIC you need some external chip, which can be a shift register, some sensor or whatever.

>>865925
see
>>865887

OP already started a thread it seems.

>>865406
Just flip the thing
>>865903
>Is there anywhere where I can find a list of things a hobby electronics person needs?
http://blog.thelifeofkenneth.com/2011/06/so-you-want-to-build-electronics.html

I finally finished my high voltage PSU
>Share your results! /diy/ loves to see problems solved and projects completed!
https://www.youtube.com/watch?v=KmLBYSGP9po

The total cost must've been around 10€! the vast majority of the components were salvaged including the transformer, bridge rectifier, flyback, heatsink, 12v psu, cables... Also the guy at the electronics store forgot to add the capacitors to the bill, I'll pay them anyway the next time I go there.

>>865971
> Just flip the thing

Were you one of those kids who just couldn't work out that the square block didn't quite fit in the round hole in preschool or do you just fail at electronics?

>>865971
>>>865406
>Just flip the thing

>>865971
>Just flip the thing
And this is the problem of /diy/, even retards can give advice and sound knowlegable.

>>859954
So I'm trying to plan an arduino-based project, but need some advice on the logistics of my idea. I'm trying to have ONE arduino transmitter, that is able to send a signal to, let's just say, FIVE arduino listeners/receivers. I need the receivers to be able to accept their own independent signal, and produce an output, such as powering on an LED. However I need each Rx to be separate and independent from the rest of the Rxs, so that if I have a set of five buttons on the Tx unit, one button will send a signal to one and only one Rx, second button will send a signal to another Rx and only that Rx, and so on.

I've looked into using the simple RC frequencies, however I've also looked into using X frequency with Tx/Rx modules on the arduinos, while using address authentication to specify which Rx unit should get a signal. Anyone have any thoughts?
>>864794
Runes... hmmm... not the Ashbringer, is it?

>>865975
>>865983
>>865984
Pls No Bully (´・ω・`)
I'm sorry, I was looking for posts to reply to fill my post to avoid posting without helping.
Edit: flip the thing, then flip it again to draw the arrow inwards.

NEETS!

US Navy Electricity and Electronics Training Series
http://jacquesricher.com/NEETS/

I just had an electrician here to replace the dimmer of my living-room with a normal on/off switch, pic related

Guy said it wasn't necessary to turn off the fuse, so he just fixed it on the live circuit

Now I just noticed that my "server" room lost electricity for 10 to 40 seconds while he was fixing it. Or, actually, dunno if it "lost" electricity, but literally everything turned itself off and turned on again half a minute later


What happened? I'm worried that the guy shortened something and damaged my hardware.

European flat / circuitry in case that matters

>>865306
>>865376

If I get a guy to laser-cut a bunch of these, would you guys be interested? I used to have one and I used it for sketching projects at my desk all the time. I figure if I get enough people on board, I can cover the costs of hiring a guy to design, cut, and mail it out to us all

Newbie here. Please don't fuck my shit up.

This is my home fuse box. It is in the entrance to my house. I want to connect a transformer for a doorbell. How do I do it? I believe all fuse terminals are taken. I think I will need a standard power wire with a live, neutral and earth sheathed. Red is 30A, White 5A, Yellow 20A

>>866030
forgot pic?

>>866030

Pic.here

Excuse me if this is.wrong place to.ask advice.

>>866033
This is definitely the right place, it's just a slower board than /b/. Give it an hour or so and you'll have a good answer.

I'm not the right person to answer your question, but someone else will know better

>>866030
I'm guessing you're in the UK?

In that case, you probably don't want to be taking anything directly off of the CU; you *probably* want to take a spur off of the ring main and then switch/fuse that, and connect in the transformer.

If none of that makes any sense to you: hire an electrician.

Also this thread is at the bump limit but I can't be bothered to create a new one.

>>866084
There is a plug socket about 0.5m from the cu, but it's in the other room behind the wall.

Are you saying drill in to the wall behind the socket, then add a L,N and E cable behind the existing socket?

>>865278
Just got mine genuine for $80 shipped.
Went from using weller to hakko.
It's nice.

>>865985
Just to be clear, are you talking about wireless communication?

I am making a switch for my raspberry pi thingy.

I don't want to uplug and plug the damn thing every time. I have a small project box and will fit this into it.
The green LED with 1k resistor is there so that I know if it is on or off.
The MOSFET is there to simulate a physical switch being turned on and off.
The capacitor is there for IDK, sh*t and giggles, I don't really need it except to iron out the power supply ripple that isn't really there. Should I delete it?

Would this work?

>>866251
Your RPI is going to have to boot up every time you power it on.

> The green LED with 1k resistor
That resistor is way too high.

> The capacitor is there for IDK, sh*t and giggles
Not really necessary if the power supply isn't noisy. RPi already has plenty of decoupling.

Why the hell do you have a 20 ohm resistor there? It's not going to do anything other than get really hot and suck a lot of current from the supply..

>>864886
the transformer output will be far from anything resembling a sine wave

>>866251
what's R2 for?

just so you can blow it up and say "WE'VE LOST R2! lollololollolollo!" ?

Instead of a resistor in this schematic I'm using a 50k pot, 1.5v battery, and a 33uF capacitor. The LED is ON and does not blink...can someone please explain why the LED only gets brighter as we lower the resistance instead of decreasing the frequency of blinking? My hypothesis is that the LED IS blinking faster than my eyes can tell.

>>865990
power went out right when he was fixing that shit

>>866124
That would be one way to do it, yes.

Do not attempt to drill through a wall where there is a socket without being 100% iron-clad certain where the cables are, and that you are not going to drill through them. Also be aware that drilling all the way through may blow the plaster on the other side.

Once you have your hole run a length of 2.5mm twin & earth between the transformer & the socket. If necessary add a fused switch somewhere before the transformer so that it's down-fused to an appropriate rating and can be switched off without having to flip the breaker for your mains.

>>866472
I don't understand your circuit. Is is supposed to blink the LED? All I see is a simple low pass filter.

>>866574
It is supposed to blink an LED but I figured out why it will not work. The LED will light up once it reaches a forward voltage and will not blink unless connected to a digital timer/counter/other discrete element.

>>866628
Side note..the LED would flash once quite dimly, then stay off until I discharged the capacitor. The voltage was steadily dropping across the LED leads which I found weird.

I wanna get into FPGA's but money is kinda tight, anyone knows a passable devboard under 50-40 dollars for general purpose fucking around ?

>>864794
>Wow Sword
>Blue LEDs.
Are you using metal to make that Frostmourne or other materials? Please post results when you finish

>>866374
>>866304

Would this be kosher?

The idea is, since I yank the power cable all the time in and out of the micro usb socket, to have the switch do it.

Does anyone know how RPI deals with the switch debouncing and stuff?

Notice that I am newbie at this.

>>867099
I think the switch itself has internal debouncing or RPI uses hardware debouncing so that users never have to worry about programming it for every single project.

I don't know this for a fact though, but I'm pretty sure

Can I do this to turn a LCD module's backlight on and off?

>>867242
pins 15 and 16 are marked NC. Not connected. :DD

Do you have a datasheet for that display though? Also don't see any other obvious error that should work fine.

I have a bunch of these grey connecters, but dont know how to attach to pcb/breadboard. I have these black and gold connector pins, do I just rip them apart into individual pins and stick into holes along bottom of grey bricks?

>>867557
I can't say exactly without examining the header blocks (the grey blocks) but using the SIL headers (the pins) like you say should work.

Are you sure the header block will not stay afloat over the board because the pins are too long?

>>867575
Nope, longside goes in deep enough that the black plastic is flush with the trench on the bottom side, only exposing the short side fo the SIL headers.
I'm a newbie though, why would the header block being afloat over the board cause issues?

>>867642
it's more mechanically sound to have the plastic up against the biggest board to prevent damage to the boards if the pin is torqued in any particular direction. keeps the pins sitting exactly straight up and all in the same direction