1W Stereo Audio Amplifier using LM386N

This is 1W stereo audio amplifier with LM386N. The output power is 1 watt for each channel, so it should be use two ICs of LM386N National Semiconductor for stereo channel. This circuit belongs to kitsrus.com and the kit is available there or at electronickits.com. This circuit only need 10mA current with best voltage supply… Read More »

Active DC Voltage Doubler

Here is the circuit diagram of active DC voltage doubler which used to increase the DC voltage. This circuit drives relays of 24 and 18VDC from a 12V power supply. Use this circuit can be work with almost any PNP or NPN power transistor, of course the transistor with specific characteristic similar to the transistor… Read More »

Low Noise Portable Mic Preamp

This is the circuit diagram of portable mic preamp. This circuit consumes low current supply (about 2mA), so will have a long battery life for supplying the circuit. Harmonic distortion is about 0.1% @ 1V RMS output for all frequencies. Maximum input voltage (level control cursor set at maximum) = 25mV RMS. Maximum input voltage… Read More »

4W Audio Amplifier using Transistor TIP41

This 4W Audio Amplifier circuit is powered by 2 pieces of transistor TIP41. The circuit is very simple and incorporates darlington output transistors that will provide more than enough output current than is needed to drive a 3-ohm speaker. The 4W audio amplifier circuit is very simple and incorporates darlington output transistors that will provide… Read More »

Mini AM Transmitter

This is the simple and low cost AM transmitter schematic diagram built using transistor BC109C. The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator is built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to 1600KHz. These components can be used… Read More »

Inverter 12V DC to 240V DC

This inverter 12V DC to 240V DC can be used to power electric razors, stroboscopes and flash tubes, and small fluorescent lamps from a 12 volt car battery. In contrast to the usual feedback oscillator type of inverter, the oscillator of this inverter is separate from the output stage, which allows easy adjustment of the… Read More »