Re: [CAD_CAM_EDM_DRO] Powerdump relay (now with free arcwelding)

Abby,

You might want to look into an SCR.
http://www.jameco.com
http://jameco.com/wcsstore/Jameco/Products/ProdDS/274642.pdf
Jameco # 274642CJ
Rated 600V, 35A, peak 300A.

SCRs latch on until the supply voltage or load goes away. They use
these in power supply shutdown circuits, which they call "crow-barring"
the supply.

Regards,
JJ

On 25-Aug-2005, at 09:17, Abby Katt wrote:

> Hi all,
>
> I have a RELAY configuration on my PSU whereby the power being shut off
> (E-stop / limits / etc) causes the transformer to be disconnected and
> the capacitor to be dumped through a power resistor. The problem I am
> getting is that the relay has been arc-welding itself in the
> ON-Position
> (and lately in the off-position).
> The old RELAY was rated 20A, and the PSU was a 55V/500W linear one,
> with
> the power resistor calculated to dissipate 10A.
>
> I'm about to install a relay rated at 30A N.O and 3A NC (The best I can
> seem to find for this voltage range) and was wondering if I could use
> some of the capacitors I have spare for preventing DC brush-motor
> spikes, to somehow limit the arcing?
>
> Any advice?
> Thanks!
> Abby
>
>
>
>
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