[Soekris] How to drive external relays?

[Poul-Henning Kamp]

In message <20060908171411.GQ24013 at mathom.us>, Michael Stone writes:
>On Fri, Sep 08, 2006 at 03:24:32PM +0000, Poul-Henning Kamp wrote:
>>A bistable relay works like many push buttons do, first time you
>>push it switches to on, second time it switches to off, etc.
>>
>>The advantage to these is that they retain the contact position
>>even if the controlling equipment looses power and they use
>>less power themselves because the coil is only energized when
>>you want to change the position.
>
>How do you get it to a known state?

You monitor the secondary contact if you have no other way of knowing.

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Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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