PWM has switching of many times per microsecond.
What if one were to use a transistor and switch at say 100ms ?
Currently I plan to put it together with relays with a 20 second timebase using a percentage of time as the driving time for relays limited to 1 second on / off.
But MOSFETs would be better for driving them at a lower current.
So, if I drove them in software with a transistor such as:
digitalWrite(fan1, HIGH);
delay(100);
digitalWrite(fan1, LOW);
delay(900);
(The fan takes longer than 1 second to slow down ;))
This would be much slower than the analogWrite function yet still give reasonable results in driving the fans.
Is that workable, or is the current consideration in using the gate driver a problem?
Transistors are like 800mA, and gate drivers around 1A (I can't find a store in Au selling 6A gate drivers), in fact - this is the only gate driver I can find:
http://www.jaycar.com.au/productView.asp?ID=ZK8878
But it's 1A, I have 800mA transistors already!
I've already got the MOSFETs I plan to use:
http://www.jaycar.com.au/productView.asp?ID=ZT2468