Relays that stay ? is there such a thing?

[terramir]

??? My question to the community is the following is there such thing as a relay
that will stay in either in switch 1 or switch position 2 without constant current needing to be applied to either one or two. I mean usually a relay stays in the switch one position and lets current through to one lead and when you then apply current it will switch to the other lead, or the relay will switch something off or on depending on where the lead is attached to. But usually in order to stay in the "B" position a constant current has to be applied to the relay. Are there relays that use the magnetic force for just a second to switch it to the b position and need current only to switch it back to the "A" position?
this would help me in designing my alarm system.

 

[nwaste]

Yeah, i heard a few a times for that relays when you apply U on it, it change the stage and the next time when you apply U on it, it will back to the first stage. It is called a BISTABLE RELAY

 

[terramir]

well I was actually hoping for a relay that has leads for each switch position (i mean trigger leads) but bi-stable relays could work too
I'm gonna search online for some now
thanks any more info would be appriciated
terramir

 

[indulis]

What you are talking about are called "latching relays". They have two coils, energize one and it flips one way, energize the other coil and it flips the other way. Also since they a latching, you don't have to have power applied to the coil all the time. I have only seen these as small, mercury wetted, single and dual "form C" (form C = SPDT) low current relays.... if I recall Magnecraft makes some.