Transistor Based H-Bridge Motor Controller Circuit controls DC motor spin both ways like clockwise, anticlockwise. Also, the circuit helps control speed and direction by easy switch method. Name “H-Bridge” comes from shape like letter H which has 4 switches and in this post circuit is 4-transistor H-Bridge. Furthermore, circuit is good for robotics, automation and […]
Hobby Circuits
DIY LED Lamp Circuit using Salvaged Parts from Blown LED Bulb
This DIY LED Lamp Circuit using Salvaged Parts from Blown LED Bulb is cheap and easy project, as it uses stuff people throw away. Here, we will learn how to change broken CFL light to energy saving LED light, also this circuit work direct with 230V AC power with no need of transformer to save […]
Simple 555 Timer Based Animal Repeller Circuit
Simple 555 Timer Based Animal Repeller Circuit is small device to keep animals away, it make high sound which animals do not like and humans mostly do not hear it; also its main part is IC 555 timer which make high frequency sound. Sound is around 15 kHz to 120 kHz (ultrasonic), therefore, this circuit […]
Timer Based Mosquito Repeller Power Saver Circuit
Mosquito repellers are popular to keep bugs away, as they use ultrasonic sound or chemical spray; but if it is always ON then they use much electricity. To solve this problem, we designed a timer-based mosquito repeller power saver circuit, it switches the repeller ON and OFF at fixed intervals to reduce power consumption and […]
Simple LED Alert for Telephone Off-Hook Detection Circuit
This simple LED circuit detects voltage drops when we lift the handset, actively turning ON an LED to show that our telephone is in use. Also, circuit is good for old phones with no light alert and it is very useful for shared phones and stops call interruptions. Here, circuit runs on simple 3V battery […]
Electromagnetic Telephone Ringer Circuit
Electromagnetic Telephone Ringer Circuit helps us know when call comes and when there is no need connect to phone line. Also, this circuit is useful when there is no access or do not want to touch phone line, as it works by sensing electromagnetic field from ringing signal and then buzzer turns ON; furthermore, the […]