PWM control for a 3-pin fan

circuit [1] isn't that much more complicated. It just uses other parts and needs a smaler transistor to switch the mosfet also probably some filtering in there.

>>1140057
well you could do it with 1 part, put a resistor in v+

>>1140072
This. Make it a rheostat if you want speed control.

>>1140072
>using resistors to control the voltage
literally nigger tier

>>1140761
I felt ashamed to even post it, I'm not even sure how it works,I thought pc fans were brushless but I have fucking akasa case fans that have a speed switch that swaps in a resistor. Couldn't fucking believe it.

>>1140057
circuit in [1] is a simple switchmode converter
also, they fucked up the footprint of the smaller transistor and had to rotate it, kek

>>1140418
>rheostat

Its not fucking 1880 anymore, we use semiconductors now.

>>1140057
555 timer. Astable configuration with a potentiometer for pwm control. Cheapest possible way of doing it that I can think of.

Of course, you're limited to control fan speed with an analog potentiometer. Otherwise get some shitty μcontroller or PIC so that you can control the pwm digitally.

>>1142566
Not OP but in similiar situation. Can you link to an article or something explaining how to do this? I know next to nothing about electronics, only what the units represent and vaguely how/why the electrons move

>>1143037
Not that guy but i wouldn't recommend that. A nig-rigged chopper circuit will do the job just fine

>>1143105
My google skills must be horrible because I can only find schematics that have choppers in them, not how to make one or even what they look like. I would like manual speed control, I tried using a potentiometer but the fan in question doesn't work almost at all with voltages below what is specified on it (12v)

>>1143297
see:
>>1142340
They talk about it needing inverted.
Here's a circuit similar to a motor driver I used(might be overkill) I'm unfamilliar with mosfets, so a mosfet may be a better solution.

output through 2.2k to 3906 PNP transistor base
3906 emitter to V+
3906 collecter through a 150+100 (2 used to keep power<1/4watt each) to TIP31 NPN base
TIP31 emitter to ground
fan from V+ to TIP31 collecter
also Diode reverse biased across the TIP31 E&C to kill high voltage motor spikes

File: Chopper-Circuit.jpg (17KB, 480x357px) Image search: [Google]

17KB, 480x357px

>>1143297
They look like this
The only thing you really need are a pulse generator, mosfet and a diode