Driving a Voltage Regulator with PWM

[flotulopex]

Thanks BrianT,

Yes, I use the CCP1 pin for HWPM.

So, it would look like this:
<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1803&stc=1&d=118292364 8">
Brian, may I kindly ask to you to explain the time constant calculation and relation to the PWM frequency? This is not clear to me as I do this usually on the "thumb" (= au pifomètre).

In fact, I made this circuit already (had a 47u cap) and could not vary the output voltage very well. But I thought this was because I adjusted the VR in "voltage" instead of "current" mode.

The voltage would change only from around 120 to 240 dutycycle (CPP1RL) and I would read between 3V and 4V.

I also corrected the output voltage on the schema...