Question about relays

I was wondering if there are any relay types that need electricity only for changing their state (on / off) ? It would be easy to use arduino… but i dont want to waste it for that.

I´d like to connect that kind of relay to old cellphone’s vibra (pager motor) contacts… and when i call that phone, then the connected relay turns something on … and when i call again, then that device will be turned off…

Yes I think they are called kip relays.

Latching relay… commonly found in old automobiles in the circuits like the hi-beams switch.

Ah, there was the word! heh, the other was Danish…

Yes, they are indeed called latching relays. They come in two forms, single coil and dual coil. Single coil changes state by the polarity applied to the coil and dual coil changes state by activating only one of the two coils at a time. In both cases you can remove coil voltage after activation to obtain zero coil current consumption. I have bought small DIP sized 5volt coil types on E-bay for less then $1 each. The ones I bought were single coil types and only draw about 13ma coil current.


But don’t most phones vibrate once for each ring?
You might have problems with that.

couple of years ago i had a phone SIEMENS M55, where i was able to make ringtones with custom vibration pattern… unfortunately i dont remember the name of that ringtone type. I edited those with txt editor.

Also I found out that i can use the speaker contacts instead of vibra motor contacts