relays, etc Re: a/c switches

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>


> what exactly does a power relay do?

	Same thing as a contactor....



		8)>>

	Same as any other relay.  Allows one circuit to
	control another, usually while providing electrical
	insulation between.  Also, the relay can be
	designed so that control voltages are differnt than
	contact side voltages: many control circuits run
	on 24vac, or 12vdc, while switching something else,
	usually higher, on the contacts.

	Some relays are designed larger, to handle larger
	currents, and get called 'power relays' or
	'contactors' or 'motor starters'.  (Useful to
	know the names if scrounging a junk heap..)
	Motor Starters usually have a built in current
	overload function as well.
-- 
	best
	dwp

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	Vernor Vinge
There are Many Web Sites which Say Many Things.
	-me