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.
Car Burglar Alarm using two 555 timers
This is a simple Car Burglar Alarm circuit that uses a dual contact relay and two 555 timers, each of them working as a monostable multivibrator.
The alarm will activate the car horn, approximately 5 seconds after either door is opened and has not been properly closed.
1 Input – 4 Outputs Stereo Audio Splitter
This 1 Input – 4 Outputs Stereo Audio Splitter has a single input and 4 independent outputs, each amplified with an operational amplifier.
Each operational amplifier is configured as an emitter follower, to take advantage of its high input impedance and low output impedance, thus avoiding distortion in sound.