Heavy duty PWM DC motor controller help

Thread Starter

eggplantparrot

Joined Mar 25, 2015
43
So the current setup won't work? If I were to to use pin 3 would the pot remain connected to pin 3 as well? And what about 7 does anything connect to it?
 
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Thread Starter

eggplantparrot

Joined Mar 25, 2015
43
Well that would mean I need to get into Ll the other parts u mentioned, like triacs and whatnot. I understand the basic theory of operation of the parts I'm using now and have all the parts already, but if all this fails miserably, I will definitely try ur suggestion
 

Dodgydave

Joined Jun 22, 2012
11,303
yes you can leave the pot on pin 3, and drive the mosfet from pin 3 also,
i think you connected the fet up wrong so it blew up your 555 chip,

you said you already have the bridge, from the treadmill, i bet there is a Triac as well,
the circuit i posted works for any induction motor AC or DC,120/230V.
 

MaxHeadRoom

Joined Jul 18, 2013
28,687
Not usual to see a Triac on a T.M. board, they are usually either SCR's as part of the bridge ( 2 SCR's & 2 Rectifiers) or Mosfets for PWM type.
DC brushed motor.
Max.
 

Thread Starter

eggplantparrot

Joined Mar 25, 2015
43
lol yea the bridge connectors got stuck on the board when I tried to take it off and I left the iron on it for a bit to long, in the end I just ripped it off
 

Thread Starter

eggplantparrot

Joined Mar 25, 2015
43
sigh, this time the 555 did not blow, but instead the IRF540 did, I made sure everything was connected as you guys posted, left pin is gate, connected to 7, middle to motor, and right to ground, as I connected the power cord, there was a little arc in the wall outlet, then a second or 2 later the IRF540 blew in to 2 pieces with a puff of smoke. ill keep the 555 for something else but I think im going to try dave's method. any suggestion of specific parts?
 

Dodgydave

Joined Jun 22, 2012
11,303
i take it your using a 12 v dc motor when the fet blew up, and not the 120V one??

The best solution is to buy a ready made light dimmer, and use a 35amp bridge reccy.
 
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