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 »
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 »
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 »
The following is 4 x 25W quad audio amplifier circuit (amplifier with four inputs and four outputs) based TDA7381. This amplifier is designed for car audio system, but you can also use this circuit for other purposes. This circuit has a design very simple and very easy to build. Schematic diagram: If properly layouted and… Read More »
This is a very simple FM receiver which build based on one transistor only. No chip or another active component. The output is connected to earphones, you need an amplifier circuit if you want to listen the radio with a loudspeaker.
Here the another audio amplifier circuit with single power IC from Phillips, TDA1514A. This is a hi-fi power amplifier circuit with 50W power output. A power IC delivers 50W single power output, then you need to build two similar circuit for stereo application. The TDA1514A integrated circuit is a hi-fi power amplifier for use as… Read More »
This is a stereo audio amplifier circuit which will deliver 12W audio power output on each channel. This circuit built based on single IC TDA1521 or TDA1521Q, supported with a few external components. General purpose power supply can be used to operate this amplifier circuit, recommended voltage: 24VDC (asymmetrical). The TDA1521/TDA1521Q is a dual hi-fi… Read More »
This is the circuit diagram of mini FM receiver that build based on single FM IC TDA7012T. Components List: R1 = 8kΩ2 R2 = 10kΩ R3 = 390Ω C1,C3 = 10nF C2,C6,C9,C16 = 100nF C4 = 33pF C5 = 25pF trimmer (Murata type TZB4Z250AB10R00) C7,C10 = 1nF5 C8 = 820pF C11 = 1nF C12 =… Read More »
This circuit is a powerful three stage, 9V FM transmitter (Tx) with a range of up to 1 kilometer in the open. It uses an RF transistor in its output stage and two BC547″s for the first two stages. Distance of trans-mission is critically dependent on the operating Conditions (in a building or out on… Read More »