rectifier with schottky diodes

[MarcoMike]

hey guys, I am building a high current 12V power supply, current as high as around 10A...
the plan is to full wave rectify the +-9 V I get from a CT transformer (large enough)

I am thinking about diodes now, the 1N400x  I use generally are not rated for that much current, and using 10 of them on each side seems weird... what I found in my drawer is a couple of 30A  schottky diodes coming from some switching PSU. they are rated for hi frequency AC, but would they still work ok at low frequency as 50Hz?
then I read the problem with schottkys is they have some reverse current, would it be a problem in my build??

thanks!

[R.G.]

I am thinking about diodes now, the 1N400x  I use generally are not rated for that much current, and using 10 of them on each side seems weird...

Using 10 1N4000 diodes is not only weird, it's almost unworkable. It is quite difficult to get diodes to share current equally when you hook them in parallel. Usually there is a range of forward voltages that makes one diode conduct most of the current. In this case, what would likely happen is that one diode would conduct enough to burn out, then the next one would burn out, then... up to the last one.

You need diodes rated at 10A or more.

what I found in my drawer is a couple of 30A  schottky diodes coming from some switching PSU. they are rated for hi frequency AC, but would they still work ok at low frequency as 50Hz?

Yes, they will work all the way down to DC.

then I read the problem with schottkys is they have some reverse current, would it be a problem in my build??

No. The reverse current will not be a factor in this build.

It would be even better to use one of the integrated bridge rectifiers which are rated at over 10A. These are often available here in the USA for US$3.00 or less. But you can use any diodes rated for over 10A.

Heat sinking will become an issue. A diode with a forward voltage of 0.5V (like a Shottky at 10A) and a current of 10A will dissipate 5W (1A x0.5V) and will get quite hot. Count on having to use some kind of heat sink.

[MarcoMike]

great! so I am gonna try with what I have and let you know in case of major fire and smoke issues!