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. Main part is IC 555 timer which make high frequency sound. Sound is around 15 kHz to 120 kHz (ultrasonic). This circuit is easy to […]
Timer Based Mosquito Repeller Power Saver Circuit
Mosquito repellers are popular to keep bugs away. They use ultrasonic sound or chemical spray. But if it is always ON then they use much electricity. To fix this a Timer Based Mosquito Repeller Power Saver Circuit is made. It turns repeller ON and OFF at set times by saving power. This also keeps repeller […]
Simple LED Alert for Telephone Off-Hook Detection Circuit
This Simple LED Alert for Telephone Off-Hook Detection Circuit shows when phone is in use by turning ON the LED. It checks voltage change when handset is lifted means off-hook. Circuit is good for old phones with no light alert. It is very useful for shared phones and stops call interruptions. Circuit runs on simple […]
Mobile Incoming Call Detector Circuit
Mobile Incoming Call Detector Circuit is smart project. Detect incoming call and make LED light up. Circuit is good for noisy places where ringtone is hard to hear. Catch RF signal from phone when call comes. Use LC circuit, transistor, 555 timer to turn ON LED. Circuit runs on 6V battery and is useful and […]
Electromagnetic Telephone Ringer Circuit
Electromagnetic Telephone Ringer Circuit helps us know when call comes an when there is no need connect to phone line. This circuit is useful when there is no access or do not want to touch phone line. It works by sensing electromagnetic field from ringing signal and then buzzer turns ON. The circuit can run […]
12V Battery Powered Fluorescent Lamp Driver Circuit
Fluorescent lamp need high voltage AC to start and keep glowing. This 12V Battery Powered Fluorescent Lamp Driver Circuit uses 12V battery to run fluorescent lamp. It change low voltage DC from battery to high voltage AC for the tube. It is good for battery device and emergency light. Circuit has oscillator, MOSFET switch and […]