File Alarm with LDR Sensor

Fire Alarm with LDR Sensor

This is the fire alarm circuit which use LDR to sense the smoke from the fire, so it can be used to detect any dark smoke. With the onset of summer season, possibilities of fire accidents […]

Heat Detector and Siren Circuit Electronic

Heat Detector + Siren

This is the diagram of heat detector circuit which already integrated with siren circuit in the output. This circuit applies a complementary pair comprising NPN metallic transistor T1 (BC109) and PNP germanium transistor T2 (AC188) to […]

LPG Gas Leakage Sensor Alarm Circuit

LPG Gas Leakage Sensor Alarm

This is the schematic diagram of LPG gas leakage sensor alarm. The circuit operates off a 9V PP3 battery. Zener diode ZD1 is applied to convert 9V into 5V DC to drive the gas sensor module. […]