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Re: Relay question

Quoting Steve Roys <sroys-at-umabnet.ab.umd.edu>:

> I was ready to buy a motor starting relay that I thought would
> have worked just fine for my Tesla coil control cabinet (proper
> voltage and current ratings), but the person who was selling it
> said that it would not be possible to use it as a simple high 
> current relay, and that I really needed a regular relay.

You want a relay that is labled as a "contactor". Contactors
are designed to make and break heavy currents under a load. For
safety's sake on a large coil I like to have my hands on the
controls of two contactors placed in series with my power circuit
to the coil. Inductive and resistive circuits behave very
differently; high current resistive circuits switch off easily,
but high current inductive circuits (read Tesla coils) don't want
to let go of the switch, especially with the high frequency
component that jumps gaps all too easily; I have seen Tesla coils
shunt the 60 cycle switch with an arc and continue to fire after
being switched into the "off" or open position with an under
rated relay. I have never had this problem with a properly rated
contactor.

Richard Quick


... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12