This 12V auto turn-off battery charger automatically disconnects from mains to stop charging when the batteries are fully charged. It serves to charge the battery of our car, using the 120/240 VAC
Power failure alarm using transformer and relay
This power failure alarm circuit is very simple and is very useful when used with electric ovens, a refrigeration systems or to prevent a thief from cutting off the electrical power because it immediately warns of the problem. It also serves you when the fuses have blown.
This Electric Current Flow Indicator gives a visual indication that there is a current flow. Possible applications for this small circuit may be: a battery charger, a voltage power source, etc.
In order to achieve our objective we place 3 rectifier diodes in series, which in turn are in series with the load / battery.