Free simple 555 timer circuits electronics projects with explanation and diagrams. Huge collection of electronics projects based on the 555 timer circuit or equivalent integrated circuits.
This 555 timer circuit Remote control Jammer device it’s useful when we need to block someone to use the remote control (children that change frequently the channels at tv).
This 555 timer circuit Bipolar transistor tester electronic project is a very a simple and inexpensive device that can be used for testing bipolar transistors types npn and pnp . If the transistor functioning properly the corresponding led indicator will flash at 2Hz.
Separate led indicators are used for npn and pnp devices. Assuming an npn test device is connected,the transistor will be biased off when IC1 output (pin 3) goes low, and will conduct when pin 3 goes high.
