I have a lamp that contains many small LED's and two rechargeable batteries. The lamp is always connected to AC mains but it is off and no light comes out of it. When the light go off or no electricity in the AC mains, the lamp turns on automatically using the battery. What is the circuit that can do that ? and How it knows that there is no electricity in the AC mains ?!
One more thing, Do automatic start up diesel generators use the same technique ?
Thank you very much, I appreciate your help
One more thing, Do automatic start up diesel generators use the same technique ?
Thank you very much, I appreciate your help