Automatic 9V Battery Charger

This is the scheme diagram of automatic 9V battery charger circuit, the parts list provided below the schematic image. The circuit was designed by Jan Hamer, translated by Tony Van Roon dan republished in this circuit diagram site. The circuit details are based on european standards: 120E, 150E, etc. The ‘E’ just stands for Ohms… Read More »

4 Band Equalizer

The following scheme diagram is the four 4 band equalizer circuit. Equalizer device is generally used to improve the fidelity of sound, to emphasize certain instruments, to remove undesired noises, or to create completely new and different timbres. This circuit operated with 12VDC symmetrical / dual polarity power supply. Power supply circuit provided on above… Read More »

4W Audio Amplifier based TDA1013B

The following diagram is the circuit diagram of simple 4W audio amplifier based TDA1013B. The amplifier is based on integrated audio amplifier chip, TDA1013B which is able to gained the audio power output up to 4W at 8 ohm loads. Wide supply voltage range can be used for this circuit from 10VDC to 40VDC. Recommended… Read More »

Pre-Amp + Tone Control with TDA1524A

This is a low noise and distortion pre-amplifier and tone control circuit in one module. Using a special IC TDA1524A, this simple circuit is easy to build and will drive most of power amplifier. Schematic diagram:

Mini FM Transmitter

This is a mini fm transmitter circuit. I think this is the simplest one. Simple, easy and of course… inexpensive… The supply voltage is between 1.1 – 3 Volts with power consumption is 1.8 mA at 1.5 Volts. This circuit should be able to cover  30 – 50 meters of range max. at 1.5 Volts.… Read More »

100 Watt Inverter 12VDC to 220VAC with Mosfet

This is another 100 watt inverter circuit diagram. Built based on IC CD4047 and Mosfet IRF540, this inverter have ability to supply electronic device -which require 220VAC-  up to 100w from 2-3A transformer from 12V lead acid battery. In the circuit diagram we can observe that 12V battery is connecter to the diode LED and… Read More »