In article ,
Ian Bell wrote:
Eeyore wrote:
Ian Bell wrote:
On several preamp PSUs I have built in that last couple of years I have
noticed the same thing. A very low frequency low level variation in the
output voltage. My latest PSU uses a series of five 100uF caps with 1K
resistors in between and it still exhibits this problem. The 'noise'
seems to be below 1Hz in frequency, fairly random and peaks typically
between +- 10mV with occasional excursions to +20 to 30mV.
Well what do you expect without regulation ?
Unhelpful replies like yours I guess.
His reply may have been unhelpful, but it was certainly to the point. I don't
get it, if you don't want to use regulation how can you expect to avoid low
frequency voltage fluctuations? You should probably count yourself as lucky
that you are seeing only "occasional excursions to +20 to 30mV", I would expect
several volts, or more, without regulation.
--
Regards,
John Byrns
Surf my web pages at,
http://fmamradios.com/