Funny reading from my PS

[Shoog]

I have just completed and tested my dual powersupply for my latest GC.
At the moment all that i have tested is the transformer wiring and the rectifiers.
The transformers are supply 19.1V into the rectifiers, and the rectifiers are showing +/-17.5V DC at the output.
I am using BYV44 diodes. Now I know about the 1.414 multiplier to get the DC voltage, so why only 17.5V on my multimeter.

I am guessing that it has something to do with the ripple and the lack of any form of smoothing caps, which is dragging the average DC voltage down. I presume that the line votage will rise when I apply the filtering caps.

Anyone care to comment ??

Shoog

 

[moamps]

I am guessing that it has something to do with the ripple and the lack of any form of smoothing caps, which is dragging the average DC voltage down. I presume that the line votage will rise when I apply the filtering caps.

Yes.😉

 

[Shoog]

Thanks.
that put my mind at rest.

Shoog

 

[Bozzz]

Hey Shoog,

Invest in a fluke true rms multimeter, this will probably give you the 25/26 volt you are looking for.

 

[Christer]

Hey Shoog,

Invest in a fluke true rms multimeter, this will probably give you the 25/26 volt you are looking for.

I think RMS values for non-sine signals are of questionable
use in most cases. If he should invest in anything it should be
a scope, then he can see what the signal looks like and read
off the peak values etc, ripple voltage etc, which are of much
more interest. A cheap multimeter and a cheap scope is of
much more use than an expensive true RMS multimeter only.

 

[moamps]

Invest in a fluke true rms multimeter, this will probably give you the 25/26 volt you are looking for.

Hi,

RMS values of AC signal and full rectified with ideal diodes are equal. Shoog's meter is fine.

A cheap multimeter and a cheap scope is of
much more use than an expensive true RMS multimeter only.

Yes. I agree.

Regards