Audio Mixer + VU Meter

This is an audio mixer circuit which designed along with VU meter circuit. The circuit is for one channel input, if you need, for example 5 channel mixer, then you need to build 5 similar circuits. The this audio mixer uses three potensiometers to adjust volume level, low frequency (bass) level and high frequency (treble)… Read More »

Wireless Car Alarm

This circuit is a wireless car alarm system that is built using two circuit modules, namely modules of transmitter and receiver modules. This circuit works on FM radio waves. Car alarms can be used on vehicles that have a 6-12VDC power supply. You can use the voltage stabilizer if your car power supply is too… Read More »

220V Light Dimmer

This simple 220V light dimmer circuit can be used to adjust the brightness of mains lights. It also can be used to adjust the speed of AC motors. It uses a triac, diac and has a radio-frequency interference (RFI) noise suppression circuit built into it as well. Schematic diagram: Components List: R1 = 10K R2… Read More »

Sound Activated Switch

This is a sound activated switch circuit. It’s will turn on and turn off based on a loud sound such as clapping your hands. You can adjust the sensitivity (how loud of a sound will activate the circuit) from a pin drop to a Mack Truck Horn. Very practical for a variety of projects. Add… Read More »

6-10W Audio Amplifier with IC TDA2002

This is a class AB 6-10W audio power amplifier circuit which built using a TDA2002 or TDA2003 power amplifier IC module. These are replacements for the original LM383 which is no longer available. It is easy to build and has a minimum of external components. The module has both short circuit protection and thermal protection.… Read More »

25W Hi-Fi Audio Amplifier based LM1875

Here the circuit diagram of 25 watt Hi-Fi (high fidelity) audio amplifier that build based on single power amplifier IC LM1875 that should be run using heatsink attached on its. Components List: R1 _____________ 1K R2 _____________ 1M R3 _____________ 22K R4 _____________ 10K R5 _____________ 180K R6 _____________ 1R IC1 ____________ LM1875 C1 _____________… Read More »

2x10W Audio Amplifier with TDA2009A

This 2x10W audio amplifier circuit power output will be 10 watt on each channel with 4 ohm speaker resistance. The supply voltage required for this circuit is 8 – 24V DC at 1 to 2 Amps. Maximum output power will only be obtained with a power supply of at least 20V and greater than 1.5… Read More »