24 Mar
2006
24 Mar
'06
3:29 a.m.
At 04:59 PM 3/23/06 -0800, you wrote:
There's still some arcing when the contacts open on inductive loads but
the mercury actually forms the contacts and since it's a liquid and it
flows it always presents clean contacts at each opening and closing. The
self-cleaning action makes them great for applications that would normally
burn out or weld the contacts on normal relays. That's also why they're
used for telephone use, they don't develope high resistance in the contacts
so they last a LONG time and are very reliable.
Joe
>From: "Roy J. Tellason" <rtellason at
blazenet.net>
>
>I have a mercury-wetted relay I salvaged out of something or other. Says
so
>right on it. :-) It also indicates that it
should be used in one
specific
physical
orientation, too.
So the advantage of those is speed?
Hi
No, it is that they don't bounce and that they don't need
a minimum current to clean the contacts. They are not
any faster than others.
Some are designed for high current operation. These look
like tubes with a coil around them. No bounce means less arcing. Dwight