[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Three phase rectifiers



Original poster: "Mike Harrison by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mike-at-whitewing.co.uk>

On Wed, 24 Jan 2001 07:50:09 -0700, you wrote:

>Original poster: "bob golding by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<yubba-at-clara-dot-net>
>
>Hi all,
>    I have worked out the wiring for my 3 phase rectifier design. I am
>going for a design voltage of 12kv at 1 amp. I would like some feedback
>on the best way to go about choosing the diodes. I am going for the 12
>pulse recifier design shown here (scroll down the page)
>http://ham.te.hik.se/homepage/sm5bsz/supply.htm
>
>This should keep the ripple low enough to not need any filter caps. This
>will be safer and cheaper. I like safe and cheap in the same sentence.
>What voltage should I aim for for the piv on the diodes? peak voltage
>will be 16968V. If I go for the old rule for caps of 2.5 peak this works
>out at 42420V. I am planning to use IN4007's this works out at 42 diodes
>per leg x 12= 504. As they are only 8 pence each this is not a great
>expense. Less than £50.00. Is there a problem with long strings of
>diodes. If I get them all at the same time there is a good chance they
>will be from the same batch. Should I go for 3 amp ones instead? I know
>it is a lot of soldering. If it works I can fully exploit my variable
>speed async gap.

I would be inclined to use 1N5408's - 1KV at 3 amps, only 5p each at
100x from Rapid Elec. and rated at 3 amps - gives you a better 'smoke
margin'