Re: E-stop relay welds contacts for load dump resistor

I'd have to agree with Dave (I think). This whole charge dump thing seems
excessive and un-necessary.

Why not wire the E-stop relay in a normally open fashion between the power
supply output and the load.

The relay would need to be rated for maximum current your load would
require.

If the E-stop is in the run condition (pulled out usually) the relay is
energized and power is supplied to the load.

If the E-stop is activated (pushed in usually), it breaks the control
voltage to the E-stop relay, the relay drops out and disconnects the power
from the load (motors and drivers). No muss, no arcs, no fuss.

The AC could be disconnected at the same time if you feel it necessary (I
wouldn't - it kills the control logic)

The power supply capacitors would still be charged, but they are safely
inside the control box anyway. Some large value bleeder resistors could be
put across them to discharge them after a few minutes if necessary. I don't
think there is any requirement to make inside the controller voltage safe
anyway.







Sage



[Non-text portions of this message have been removed]