/diy/ - Do It Yourself

You'll just fry the resistor. Those are only rated for 1/4 watt.

>>1903644
Can't I just bunch them up? I don't really know what I'm doing FYI!

>>1903641
>>1903668
yea sure, just get yourself one of pic related

>>1903641
copy pasta

>>1903641
you dumb motherfucker. adding resistors will just make MORE heat not less.

>>1903817
P=e2/r
More resistance equals less power you fucking mongoloid

>>1903829
P=E^2/R rather because 4chan eats formatting

>>1903641
You actually bought this piece of shit after watching big clive's tear down of it?

https://www.youtube.com/watch?v=iB0jyFFZvYk

>>1903829
AND where does that power GO cock mongler? hmmm dick slurper?

IT TURNS IN TO HEAT. Captain short bus.

>>1903840
>Turns off a switch creating an open circuit.
>Insanely high resistance of air gap melts everything within 5 foot radius.

>>1903876
all resistors produce heat when they restrict current. infinite resistance doesn't pass anything and therefore does not heat up.

However lighting when passing through the air generates a crap ton of heat to over come the resistance of air.

try again.

>>1903641
You must learn ohms law and see how to use resistor. More resitance = less current but you want big current so use BIG small resistor. Hope that helps and Good Luck.

Rahul

i don't have audio i can't watch big clives teardown
resistor would need to be rated as other anons suggest however the motor in the case as a blower its possible some of the heat will be trapped in the case so it would work a tinny bit but not usefully.
is the heater ac or dc powered? there is a rectifier for the motor, if you can put a diode in series with the heater element and its on full wave ac or full wave rectified and you take out one of the bridge diodes it will half the heater element output.

>>1903909
Yeah, that's how you know you're wrong, bud. It's the limiting case. When you add resistance, power flowing through the circuit goes down. Like I'm not the person you're responding to. You are really failing at this.

Electrons DO flow through the air, it's just the resistance is so high, not many of them do. No circuit is truly "open".

You fucked up the equation post too.

Basically you keep showing you actively don't understand what's being said.

If the resistance goes up for the same voltage, current goes down, so power consumption goes down. Let's say all that power is heat. It's less total power, so less total heat.

More resistance = Less power = less heat.
Yes, the power across the new resistor would be dissipated as heat, which is obviously where you are getting confused, but by increasing resistance, there's less total power being consumed.

You are really fucking this up.

>>1903928
>>1903837
look at his circuit, if its 150w the current in the element is like .6A or so, use 1N4004 diode in heater loop.

>>1903930
>Electrons DO flow through the air, it's just the resistance is so high, not many of them do. No circuit is truly "open".
vacuum

>>1903837
There's nothing really scathing about that review though; he simply highlights some deficiencies in the design that were made in order to produce the product for a specific cost. He even goes on to state that it could be a useful device for a variety of applications, just that it should be monitored while in use and the output should not be blocked. You should use some common sense when buying anything chinese-made involving heaters: don't use them unattended and don't use them in stupid ways.

>>1903930
please go back to school and start over.

>>1903641
You could just hack a light dimmer (triac type) in the heater circuit. As long as the dimmer is rated for the full power heater load. To a triac dimmer, a resistive load is a resistive load. Heater, light bulb. Makes no difference.

>>1903641
Install some sort of thermal switch that turns it on when heat needed, off when it gets too hot.

>>1903988
Are you suggesting electrons won't follow an E-field in a vacuum? It's more about how bound they are in a material and the force required to free them than what material is or isn't in the field.
Had you thought about it even for a moment you would have figured this out.

>>1904020
retard

>>1903829
No, P = V * I * cosine(ϕ) * ( (∫sin(ωt)^2dt) / T )

>>1903641

Install a variable resistor with an amperage rating at least 1.5 times the amps on the heaters name plate.

Make sure the resistor is rated for constant load.

Ywah you could do all that or you could just buy a decent heater with a thermostat and have it do it for you

either way good luck

also all heating elements are a resistor in the same way that all devices are resistors but resistors are not fucking heating elements

please take electronics past dc theory guys its fucking embarrassing

>>1904072
electrons != electricity
retard

>>1904133
>>1904074
>>1904072
>>1903930
>>1903909
>>1903876
>>1903840
>>1903830
>>1903829
>>1903817
A loaded resistor has a value of resistance which maximizes the dissipated power.
Zero resistance won't dissipate power, as there is no voltage drop.
Infinite resistance won't dissipate power, as there is no current flow.
Stop being angry at your own collective ignorance and shut your traps, you are not helping OP.

OP, do you have a multimeter?
Please tell us the mains voltage of your area, and the series resistance of the heating element if you can measure it.
As I see it you have three options:
-Install an adequate resistor to limit power.
-Vary the input voltage with a transformer.
-Use a PWM (some fan speed controls use this).
Depending on the power of the heater and if you want regulation or not, some could work better than the others, and cost more or less.

>>1904280
I have a degree in EE, faggot

>>1904370
I have a degree in AE, degrees don't save you from being wrong.

>>1904283
230v mains, have to check the heater later. Considered trying one of these if they work, might need higher output later.

>>1904501
See the power that thing is rated for before buying it.
CFD lights are usually 10 to 50 times less demanding than a heater.

>>1903930
You are a fucking moron.

If op has a heater that uses say 12v at 1 amp would need a 12ohm resistor to produce 12 watts.
if you reduce the voltage to 8 volts the amps will still be the same and you will need a 4 ohm resistor that will need to dissipate 4 watts of power.

net wattage is 12 watts. Sure it will only blow 8 watts of heat out the front but it still will generate 12 watts of heat in total.

Thus endeth the lesson.

>>1904370
>I have a degree in EE, faggot
I've known a few EE's they are stupid mother fuckers. some of them don't even know what a linear power supply is or how to make one. I actually had an EE (when I told him I had just built a power supply) ask "if I used a raspberry pi or arduino" to build it. he was astounded that I built a regulated power supply without any computers. it fucking boggled his mind.

saying you have an EE but spouting off know nothing bullshit does not help you.

If OP wants to reduce the amount of heat. The easiest thing to do is reduce the voltage output of the power supply by adding diodes to drop the voltage (assuming DC output to the heating elements) OR add dropping capacitors (for AC).

diodes in series will drop the voltage in .7 volt increments.

>>1904283
>the series resistance of the heating element if you can measure it.
the unit has a PTC heating element so the cold resistance and hot resistance will be different.

The heater runs directly off mains so the only way to limit the heat is to drop the voltage going in to the unit.

>>1905223
> current draws 1 amp no matter the resistance
checks out, free energy lads, let's do it

>>1905223
>12v at 1 amp would need a 12ohm resistor to produce 12 watts.
Correct
>if you reduce the voltage to 8 volts the amps will still be the same
The amps would fall proportionally (8/12) because the resistance of the heating element hasn't changed
Also: 8V/4ohms = 2A, so it'd be 16Watts

>If OP wants to reduce the amount of heat. The easiest thing to do is reduce the voltage output of the power supply by adding diodes to drop the voltage
Diodes use power too. P=I*V , the same as resistors

>>1905223
You dont even know which post(s) was me you absolute tard. For the record it was these >>1904370 >>1904133

>>1903641
You need to use an AC chopper circuit to reduce the cycle duty and thus power going to the heating element.

>>1905394
Phase angle control is your best bet in that regard

>>1903641
A diode in series with the heating element will chop the heat produced in half, assuming the diode can handle the 340V peak and whatever current used by the heater. 2A diodes are kinda common, 10A diodes not so much. If you tried to halve the heat output by putting double the resistance in there (assuming the extra resistor could handle the power) then half of your heat wouldn't be coming from the element but from the resistor. This isn't an issue with the diode. If you actually want to adjust it, then I can only recommend a phase-fired dimmer rated at enough power, or installing a bimetallic switch somewhere smart.

Though if you have a spare motor capacitor lying about you might be fine making a fixed capacitive dropper. Might.

>>1905223
Increasing resistance while keeping voltage the same means lower current, because I = V / R. Normal power supplies keep the voltage constant. Current and hence power will change as a function of voltage and resistance; they're the dependant variables. Lower current with a constant voltage means lower power, as P = I * V.

>>1905394
>>1905396
>>1903641

Actual space heaters have a few cheap, simple methods for varying output when they have that option. You could probably control yours using a regular light dimmer knob, just make sure it can handle the full amperage of your heater. I made a dimmer outlet for my friend to adjust the temperature in her snake's tank. Not precise but good enough for that. While it does work, the dimmer switch itself must dissipate heat. Do not overload it. The old style ones are variable resistors - avoid! - but the newer ones are rapidly switching triacs. Because they turn the power off, they are actually 99% efficient; your heater at half load doing say 250 watts will heat the switch up to 2.5 watts.

You can also get $30 wall plug thermostats on amazon that just switch off outlet when they get hot enough, turn it back on when it gets a little cooler. That's what you want if you're just heating your room.

If you really want to modify your heater, here's how they work. Some have several hot wires, the switch connects voltage across the entire heating element or just part of it. Or it has several elements. Simple switch control.

Temperature control is done with bimetallic strips that open and close the circuit at the temperature threshold. When it's on, it's on full power. Some fancy ones have external thermostats, some use PWM like an electric stove does, or a CLR circuit to change the phase angle.

Don't burn your house down.

>>1903817
Resistors only dissipate heat relative to the amount of power going through them. More ohms = less watts = less heat.

>>1905223
Hello I see you are confused about ohms law and arduino... but keep at it you will be goos one day. Remember resistor codes and capacitor plus and minus. Good luck.

Rahul

>>1906740
>Don't burn your house down.

OP here, I might just buy one that lets me regulate the heat, like this thing is 12 bux and probably won't catch fire because I rigged some shite in as apparently the topic is more complex than I expected!

This >>1904049 is the only reasonable answer in this entire thread.
You need a device called a THERMOSTAT, not all of them are suited to switch mains power though, be mindful of that.