I am looking for a relay that when power is initially applied to the coil the contacts don't change state until power is removed. Then after a set time the contacts should go back to normal state. Any ideas?
darn, beat me typingIf I wanted to do it with readymade relays, I'd use one normal relay and one "true off delay" relay.
The NC contact of the normal relay is in SERIES with the NO contact of the off-delay relay.
- Apply voltage to both at the same time.
- The NC opens , the NO closes
- turn off the power supply
- the NC of the normal relay closes and the NO of the delay relay remains closed for the adjusted time.
The actuation time of the off-delay relay has to be slower than that of the normal relay, if not you can put an On-delay relay in series with the Off-delay relay.
If seen Off-delay relays for up to 300 seconds..
Of course this solution is expensive. If you build your own circuit it'll get much cheaper.
LOL, I hadn't read your post while I was writing...if you want a time delay after power is removed, then you should be looking for electropneumatic off-delay timer relays. They will switch immediately when power is applied (which if I understand correctly is what you don't want), but you could get around this easily by adding another relay in series (contacts in series, coils in parallel).
likewise. I think we hit submit at the same timeLOL, I hadn't read your post while I was writing...