Insect Repellent

This insect repellent circuit will repel insects such as mosquitoes, flies and cockroaches from your home or yard effectively. circuit uses a specific frequency to disrupt the insect so the insect will go away from this circuit. This insect repellent circuit can be placed inside or outside the home (for speakers). If you want to… Read More »

PCM2706 USB Sound Card

Here is the USB sound card circuit based on PCM2706 which dedicated for USB audio. With USB controller module inside PCM2706, there is no more additional programming to the IC. The computer system will automatically detect this circuit when connected to the USB port. You will get stereo audio channel output from this circuit. Schematic… Read More »

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 »

20W Bridge Amplifier using TDA7240A

This is a simple 20W bridge amplifier based on TDA7240A. This circuit is designed for car audio system, but you may use this circuit for your small home audio application… 🙂 . Schematic Diagram: This circuit operated with 18VDC asymmetrical power supply (positive (+) and ground only). Mount the power IC on a heatsink to… Read More »