Doktor Jones
Member
I have a device that's powered by a 5V DC adapter; I would like to set something up so that an LED blinks when power is lost. I already have an LM3909 that will be connected to an AA battery for the blinking circuit, so that's taken care of, I just need a way to turn it on when the 5V power power is lost.
I know I could use a 5V SPDT relay, with the battery wired through the NC contact... but is there anything simpler/more electrically efficient than a relay? I'd like to go solid state if possible.
I know I could use a 5V SPDT relay, with the battery wired through the NC contact... but is there anything simpler/more electrically efficient than a relay? I'd like to go solid state if possible.