Batteries. Needed for just about every electronic project, electronics revolve around them. But think about it, What happens once they lose their power?We throw them aside. These batteries are building up in our landfills, so I set myself to find out how to reuse them.

here we have developed this battery monitor circuit to test the battery charging status. In this circuit we can easily test batteries by connecting it with the circuit. Here some LEDs are used for showing battery status.

Whether it's an electronic noob or an expert engineer, all require this indispensable piece of equipment called the power supply unit. This is because no electronics can run without power, to be precise a low voltage DC power, and a power supply unit is a device which is specifically meant for fulfilling this purpose.

This is done by connecting the OUTPUT of each timer to the TRIGGER of the other through a diode and placing a resistor in the trigger circuit. The resistor limits the current from the opposite timers output when the trigger is closed on the stopped timer.

555 time IC is very powerful and versatile IC, it can be used in many forms. In this tutorial we are going to see how a 555 IC can be used as Audio Amplifier. A low power audio signal can be amplified using 555 Timer IC.

The concepts of these mosquito repellers are simple and we can build a simple mosquito repellent circuit at home easily by using 555 timer IC and few other commonly available components. Let’s see the concept of mosquito repellent circuit in detail.

When the 555 IC is used to produce an MONOSTABLE circuit - it will only pulse once. Monostable circuits can be used to turn lights/LEDs on or off just once. They are also used in many more school based circuits.

Reaction timer is a game to test how fast you reacts. This game which we have developed using 555 IC is for two players where first player starts the game by pressing start button. As soon as the START button is pressed, 7 segment display starts displaying 0 to 9 numbers in a high speed.

Bust out that 555 timer and use it to build your own AM radio transmitter. The circuit that is using only needs the timer chip, an NPN transistor, three caps, three resistors, and a potentiometer. It generates an amplitude modulation signal around the 600 kHz range which you will be able to pick up with any normal AM radio.

555 Timer IC is one of the commonly used IC among students and hobbyists. There are a lot of applications of this IC, mostly used as vibrators like, ASTABLE MULTIVIBRATOR, MONOSTABLE MULTIVIBRATOR and BISTABLE MULTIVIBRATOR. You can find here some interesting circuits based on 555 Timer IC by using these different operating modes.