12 dc fan speed controller schematic using MJ11032 or mj11016 darlington needed .

[mark krawczuk]

hi, i am after a basic type schematic to controll the speed of a 12 volt
dc automotive cabin fan .

seems to be a bit of a problem in these saab`s.

any schematic using a mj11032 or mj11016 darlington would be good. if
not any electronic speed controll schematic will be fine.
the original darlington is rated at about 25 amp , seems a bit excessive....
these darlingtons i have are rated at 30 and 50 amp.

thanks, mark k

 

[Jamie]

hi, i am after a basic type schematic to controll the speed of a 12 volt
dc automotive cabin fan .

seems to be a bit of a problem in these saab`s.

any schematic using a mj11032 or mj11016 darlington would be good. if
not any electronic speed controll schematic will be fine.
the original darlington is rated at about 25 amp , seems a bit excessive....
these darlingtons i have are rated at 30 and 50 amp.

thanks, mark k

A simple Pulse Width Modulator (PWM) will drive those babies
fine!..
YOu can make a simple one via a 555 timer..

http://www.cpemma.co.uk/555pwm.html

That circuit is good for 5..95% power.
if you want 0..100% duty cycle, then you'll need
to use something different like a dual op-amp.
one channel as the triangle Oscillator and the
channel for the comparator and speed control.
I think if you have an on/off switch in the circuit,
the 555 timer will work perfectly.