Re: [CAD_CAM_EDM_DRO] Another power supply question....Rectifiers

You might experience a few tenths of a volt more voltage drop across the
bridge with the 25A unit, but other than that, it should be okay to use.
One point, though, ...you might be able to draw such high currents through
the secondary as to burn it out. Check your design so the circuit never
draws more than 115% rated for more than a few minutes. BTW, did you check
the wire sizes of the secondary to see if they will support a 10 Amp DC
load? Also, what size is the lamination, and how much stack? I don't think
you'd want to have less than 2 sq in of center-leg core in the transformer
for the output power you want. (If you've 1" E-I laminations [3" wide x
2.5" high], then you'd want at least a 2" stack of lams. Also, are the
windings wound with a common ct? (see below)

RayHex

is this what your secondary looks like? 32v outside taps, 28v inside,
common ct?

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> From: RC <asdf@...>
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Another power supply question....Rectifiers
> Date: Tuesday, April 23, 2002 7:48 PM
>
> Ok, first of all, thanks goes out to all how had suggestion and comments

on my cap and transformer questions! Oh by the way, the transformer is a
Power One brand, and has 5 secondary, hope this helps.

>
> The next question, is Bridge Rectifiers..... Now as you know I am

building my first power supply, and needing lots of information, should of
finished that Electronic Tech School many years ago! The question is
picking the best fit bridge rectifier, for the 30 DC plus volt @ 10 amp
power supply. I know to use a larger volt/amp rating then what the power
supply will produce, but for some reason the rectifiers go from 1~6 amps
and then jump to 25 amps at a reasonable cost! The 12 amp rectifiers are
three times as much in cost as the 25 amp ones! So is it ok to use the
higher amperage ones vs. the costly 12 amp units?

>
> RC