Power Circuit from PWM

[buckrogers22]

I need to power a small microprocessor circuit which will have a 5 volt regulator. The power source is a 0-12V PWM operating at 100Hz. I realize that I probably won't be able to drive this circuit at less than 45% duty cycle. I thought that I was onto it by building a simple low pass filter. It smoothed out the PWM, but I guess it isn't good as a current source.

Please help!

 

[barry]

Not sure, but maybe you can get away with a rectifier and cap?

 

[vinodstanur]

I think you can connect a high value capacitor parallel to the output of the PWM. Also, you may require a diode in between the output of PWM and the Capacitor. (otherwise the capacitor may discharge through the PWM circuit when its output become 0)
Some thing similar to the half wave rectifier...

---------- Post added 02-10-11 at 00:00 ---------- Previous post was 01-10-11 at 23:53 ----------

also the efficiency of above system increases on increasing the PWM frequency and decreases on increasing the output load...

 

[buckrogers22]

Thanks for the suggestions. I'll try a diode and capacitor.

 

[buckrogers22]

That worked quite well. I was making it harder than it had to be. Thanks for your help!