Simple Fire Alarm with Thermistor and NE555

The following circuit is a simple fire alarm circuit based NE555 timer and use thermistor as a temperature detector. This sensor will activate the transistor when the temperature is in high value. The thermistor will have a low resistance at high temperature, while at low temperature, the transistor resistance is high. This characteristic of thermitor… Read More »

Simplest RF Transmitter

This is probably become the simplest radio frequency RF transmitter that you will find anywhere. It has a total of five parts and can be constructed into a very small space. It is great for science fair projects or other science related projects where short range transmission is useful. It operates on 1.5 to 3… Read More »