Re: Power Supply

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

> The reason is that you are using a capacitor-input filter, which
> delivers the
> peak of the sine wave. A 24 V RMS sine wave has a peak 1.414 times
> higher, that is 33.9 V. So, your results are exactly as

expected. If you

> need 24 V DC, you should use a transformer with a 17 V RMS output.
> The relays probably don't take a lot of current, so you could just

add

> a separate transformer for the 24 V DC stuff.
>
> Jon

Jon,
Thanks for the reply. But the reason I am asking this question is
mostly for a better understanding of how this stuff works. I do
have a viable option in place to get the 24vdc I need. But I am
confused. I understand the diff between rms and and peak, and that
you get close to peak out from my setup. But I would have thought
that Bridgeport (Textron) would have set it up to get the correct
24vdc out, i.e., using the proper transformer size. There is
another dc supply piggybacked into this setup for -22vdc. It
powered some of the logic cards from bp that are now eliminated. It
only jumped to about 26vdc with my higher main power. After running
some crude numbers, this seems correct. It gets the same input ac
of 127v (supposed to be 115v) from the same isolation transformer as
the offending 24vdc supply does. The only difference I can between
the two is in the step down transformers they use inside the supply
itself. The problem supply, according to the bp wiring diagram,
uses what looks like a transformer with with two same sized
secondary coils in it. The legs of each coil are labled 0 and 28.
The 0 of both coils goes to the same side of the bridge rectifier,
and the same for the 28 leg of botth goes to the other side of the
rectifier. I am not sure what effect this has on supplied ac to the
rectifier. I have never run accross this type of setup in my
limited experience with electrical applications. Any insight would
be much appreciated. I would love to pointed to a resource where I
could read up on this stuff. Like I said before, I am newbie, so is
this stuff is O.T. or inapropriate to the group, please forgive me.
Thanks.