See Many simple electronic circuit that is very important on this sites. My friends used to say the large projects, from small several circuits to combinations.
It can charge any size of the Gel cell batteries and extend the life of the Gel Cell battery. While the circuit is running, the LED indicates charging.
In a normal circuit, the general LM350 regulator has a start voltage of 1.25V. But this circuit is special that start of 0-volts. We use only one IC and a few other components. So cheap and easy for you.
This is a 4 transistor audio amplifier circuit. Which is a 4-transistors complementary push-pull amplifier, that shows the basics of audio amplifier design.
