Stereo Tube Amplifier 4 Watts

This is the circuit diagram of stereo tube amplifier using 6SQ7-GT and 6V6-GT. The tube amplifier circuit is uses the total of 5 power vacuum tube. The diagram is based on the output section design of typical late 1940’s old AM Trutone radio with 6 tubes. The output will be 4 Watts per channel (2x4W… Read More »

5V Regulated Power Supply with OverVoltage Protection

This is the circuit diagram of 5V Regulated Power Supply circuit, featured with over voltage protection. The circuit is based regulator chip 7805; Thyristor SCR 2N1595 and Dioda Zener 1N3997 for overvoltage protection circuit. The 5V regulated power supply is apply 74LS series integrated circuits which has to be really precise and tolerant of voltage… Read More »

Ultrasonic Motion Detector

This is a ultrasonic motion detector (or movement detector) circuit. The circuit claimed has a high movement sensitivity. Even air moving (hot air rising, wind blowing) will trigger it when the trimpot is set near the most sensitive position. The transmitter sends out a steady ultrasonic tone at 40kHz. At this frequency the wavelength is… Read More »

1.3W RF Amplifier

This diagram is a schematic diagram of RF amplifier circuit. The circuit will amplify the RF signal about 10 times, 100mW input power to 1.3W output power. It use a general NPN RF transistor 2SC1970. You may apply other transistors, for example 2N442. Circuit Diagram: Circuit Works: RF system and specially in RF amplifiers, this… Read More »

5V Regulated Solar Cell Power Supply

Powered with solar panel, the circuit will give you 5V pure regulated DC voltage. This solar cell power supply circuit is made up of an oscillator transistor as well as a regulator transistor. The solar panel charges the battery when sunlight is bright enough to generate a voltage above 1.9v. A diode is necessary between… Read More »

3-Rail (+12V) / (+5V) / (-5V) Regulated Power Supply

This circuit generates 3 source regulated voltages applying a minimum of electronic parts. The output DC voltage are +12V ; +5V and -5V. Diodes D2 and D3 conduct full-wave rectification, at the same time charging capacitor C2 on each halves of the alternating current cycle. At the same time, diode D1 with capacitor C1, and… Read More »