Re: [CAD_CAM_EDM_DRO] Re: BP Power supply

Hi Nathan,

> Are chokes the three things that look like transformers? I think

That's the ones. They were originally used as a very crude method of
reducing the motor idle current. Be careful when removing the
transformer and chokes, they are very heavy.

The capacitors are probably 5400uF or 5.4mF. I used two in parallel
(connect + terminals together and - terminals together) but it is
probably better to use 3. I am not sure what the 4th rectifier was for -
it may have been part of the DC supply for the chokes. With your new
power supply you will only need one rectifier so you have 3 spares. The
rectifier will get hot so it needs to be bolted onto a metal plate with
a small amount of heatsink compound (white thermal grease). I bolted
mine to the big metal plate on the back of the case that everything else
is bolted to.

I put a relay in one of the AC feeds into the rectifier, controlled from
the emergency stop circuit. If you are going to use a relay to switch
the drives on and off, make sure you fit it on the AC side. With no load
the power supply voltage will wander up to about 85V. If you have your
relay after the capacitors then this will get dumped into the Geckos.
They should be able to take it OK but why take chances?

Les


rocketscientistnate wrote:

> Are chokes the three things that look like transformers? I think
> now that I know which transformer to use, I'm ready to go. Let me
> regurgitate some to make sure I'v got it right. Remove the 3 phase
> transformer, remove the chokes, rewire the remaining transformer for
> 55V, wire the rectifiers ~(AC) terminals to this transformer, and
> the + & - to the capacitors and then on to the gecko drives. My
> capacitors are 200V 5.4 Farad. Do I use only one per axis? There
> are four rectifiers, labeled X Y Z and the fourth label was
> unreadable. What's it for?
> Thanks
> Nathan
>
>