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 […]
DIY Water Level Monitoring Circuit
DIY Water Level Monitoring Circuit is good for tank or reservoir. It use IC 555 timer in astable mode and make repeated signal. When water reaches a set level then buzzer turns ON. The circuit helps to stop water overflow and is useful in home, factory and farm. Circuit Working: Parts List: Component Quantity Resistors […]
Tone Generator Doorbell Circuit using Dual IC 555 Timers
This tutorial is about Tone Generator Doorbell Circuit using Dual IC 555 timers. This circuit is simple and works well when button is pressed. One IC works in astable mode and other in monostable mode. It is very important for making sound to run a 8Ω speaker. The circuit needs 9V DC power and makes […]