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. The SEN-1327 gas sensor module from RhydoLABZ is applied in this circuit. Its output goes higher when the gas… Read More »

Toy Car Remote Control

The circuit, consisting of an infrared transmitter-receiver pair, utilizes IR beam transmission to switch the toy car “on” or “off’, yeah… it will be only switching on and switching off, you may modify this circuit to make the toy car to turn left or right. To operate the toy car, you have to hold the… Read More »

Laser Communication (Transmitter – Receiver)

This is the circuit diagram of laser communication system that transmit the sound or music signals by way of a laser beam. The intensity of the laser beam varies together with the amplitude of the sound signal. The variation within the intensity of the laser beam is converted into a variation in the voltage level… Read More »

Seismic / Vibration Sensor

This is the circuit diagram of seismic / vibration sensor. The circuit simulates a seismic sensor to detect vibrations/sounds. It’s really sensitive and may detect vibrations due to the motion of animals or human beings. So it could be utilized to monitor protected locations to restrict entry of undesirable individuals or animals. The circuit applies… Read More »

Electronic Motor Starter

The above diagram is the schematic diagram of an electronic motor starter circuit. This motor starter protects singlephase motors against voltage fluctuations and overloading. Its salient function is a soft on/off electronic switch for simple operation. The transformer steps down the AC voltage from 230V to 15V. Diodes D1 and D2 rectify the AC voltage… Read More »

Electronic Siren based NE555

Here the circuit diagram of electronic siren based NE555. This circuit produces a sound like factory siren. It applies a 555 timer IC which is utilized as an astable multivibrator of a center frequency of about 300Hz. The frequency is controlled by the pin 5 of the IC. When the power supply is switched ON,… Read More »

150W Power Amplifier

This is the very simple circuit diagram of 150W power amplifier. The circuit is easy enough to built without PCB. The power output range is about 100-150W depends to the power supply and the Darlington’s you use for the amplifier. Heatsink is a must since the final transistor is going to hot when the amplifier… Read More »

1500W Power Amplifier

This is a very high 1500W power amplifier circuit diagram by Rod Elliott. The circuit is built using 10 pairs of power transistor MJ15024 and MJ15025 (or MJ21193/MJ21194), then it will use 20 pieces of power transistor for final amplification.

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