Originally Posted by IT Diva
Originally Posted by Solonowarion
Thanks for that Darlene. Good. Read.
And it just sort of occurred to me that I may be able to pick off just 5V of the PWM part of the output, which would then be able to control any 4 wire PWM fan or pump. . . . .
That is if they'll run OK with a 45Hz PWM frequency instead of the 25,000Hz that's standard.
That would be really effin' cool . . . .
Let you know if it works in a couple hours or so . . .
I was able to pick off just the PWM part of the output, and limit it to 5V so that it matches the voltage for a standard PWM signal.
Better yet, it only took a few passive parts and can be simplified a bit more with a 7V zener diode.
Naturally, I'll have to order some since all I have close are 5.1V ones, necessitating a divider network to knock down the 6.9V to 5V.
To test so far, I used a PWM CPU fan to see what kind of results I got since the PWM frequency from the controller is only ~45Hz, and PWM devices are normally run with a 25KHz PWM frequency.
I got nice linear speed control with the fan powered from a 12V molex and controlled by the 45Hz PWM component of the controller's output.
The controller displays the RPM just fine as well.
I'll let it run a while tomorrow morning while I have my coffee and decide whether to try it on a pair of $100 pumps.
I'll post an update with pics in the morning,
DarleneEdited by IT Diva - 8/30/13 at 9:55am