This project for Digital Display AC Line Tester Circuit is a small electronic tester used to detect the presence of mains AC voltage without direct contact. It is a wireless mains voltage tester. When the sensing probe comes near a live AC wire then the circuit detects the field and shows the count on a […]
555 IC Based Schmitt Trigger Circuit
555 IC Based Schmitt Trigger Circuit is a small project. It work like comparator and comparator is ON/OFF when input cross the voltage. Noise make output jump and Schmitt Trigger stop this. It have 2 limit: high and low. Input goes high then output is ON. Input goes low then output is OFF. Between them […]
Simple Wire Loop Security Alarm Circuit
Simple wire loop alarm is small security circuit. It uses thin wire as sensor loop. If loop is cut or opened the buzzer will sound. It works on 9V battery, needs few parts, is cheap and easy to make. Circuit Working: Parts List: Component Specification Qty Resistors 4.7M 1/4 watt 1 100k 1/4 watt 1 […]
Buzzer Alert at 0°C Indicator Circuit
In winter season, water and surrounding air can go below zero degree. At that time it is useful to have a small alarm which tells us when temperature goes near freezing point. This Buzzer Alert at 0°C Indicator Circuit uses thermistor sensor, one op-amp IC and a piezo buzzer to make sound alarm when temperature […]
Slow Voltage Rise Power Supply Circuit
Sometimes when our circuit power is ON a big current comes suddenly. This sudden current can damage parts like IC, capacitor and transistor. To stop this we make Slow Voltage Rise Power Supply Circuit. This circuit gives voltage slowly but not full at once. So circuit become safe and work is quite reliable. Circuit Working: […]
LDR Based Aircraft Warning Signal Light Circuit
In tall buildings, towers or high structures it is important to show warning light for aircraft safety. Normally a red 230V LED bulb is used as warning lamp. This LDR Based Aircraft Warning Signal Light Circuit automatically switches ON the bulb in night and switch OFF in day. It uses LDR sensor, relay and small […]