It is better (and more polite) if you start your own thread with your question. For context, you can reference other thread with links.

what kind of a circuit will help in this?

Unless you use a non-volatile device such as a flash RAM chip, an electronic circuit cannot remember its last operating state when completely unpowered. To do that, as in this thread, the solution is a mechanical assembly that controls one or more switches. See post #11.

ak

 

It is better (and more polite) if you start your own thread with your question. For context, you can reference other thread with links.



Unless you use a non-volatile device such as a flash RAM chip, an electronic circuit cannot remember its last operating state when completely unpowered. To do that, as in this thread, the solution is a mechanical assembly that controls one or more switches. See post #11.

ak

hi E,
I have a similar requirement.
The latching relay will switch over its contacts and remain in that state after the ON/OFF pulse has been sent, even if the power is removed.
And it will change its sate again only when power is turned on again according to the pulse it gets after the power is on.

what kind of a circuit will help in this?

thanks in advance.

Search Latching Relay and you'll find a mechanical device that holds its state based on the last input. As AnalogKid said, an electronic version will need to be a non-volatile memory along with programming that reads that state. Sounds like you're looking for a mechanical solution. HERE is one such sort. You don't say whether you need SPST or SPDT or DPDT type, nor do you say if you're looking for an AC type or DC type. Voltage of the operating coil is another detail along with the amperage rating of the switching contacts.

 

Here's another:
https://www.amazon.com/HiLetgo-Single-Bistable-Self-Locking-Module/dp/B01HHM5M4M/ref=sr_1_1_sspa