Simple Bench Amplifier

Above schematic diagram is a small 325mW amplifier circuit based on LM386 with a voltage gain of 200 that can be used as a simple bench amplifier, signal tracer or used to amplify the output from personal radios, MP3 players, MP4 Players or iPods.

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 »

100W RF Amplifier with BLY94

This is a 100W RF amplifier built based on RF power transistor BLY94. Active components: BLY94 Coaxial cable length : K x Lambda / 4, where K = 0.66 for 50 ohm cable and K = 0.8 for 75 ohm cable. L1 = L6 = 2 turns / 1.5mm / 14mm L2 = L7 =… Read More »

UHF TV Antenna Booster

This is the circuit diagram of UHF band TV antenna booster with 15dB gain power. This low cost antenna booster is simple and easy to build.It use single transistor BF180 to boost te UHF signal. Since this is an active circuit of UHF TV antenna booster, it will require a 12v power supply to operate.… Read More »

LED Color Fade Effect

This is the circuit of LED color fade effect. Just like the name of the circuit, the light intensity of LEDs in this circuit will fade from high  intensity to low intensity and then off. Here the final result preview:

2 x 22W Stereo Car Audio Amplifier with TDA1553CQ

This is the circuit diagram of 2 x 22W stereo car audio amplifier. The circuit is powered by a single IC TDA1553 with some external components, this IC will handle your stereo car audio system. The TDA1553CQ is a monolithic integrated class-B output amplifier in a 13-lead plastic DIL-bent-SIL power package. It contains 2×22 W… Read More »

80W Power Audio Amplifier with LM12

This is the circuit diagram of 80W power audio amplifier based on power IC LM12. The circuit kit is sold at electronic part/component store, the design is proven to be valid and work. This amplifier use dual polarity power supply to operate. Here the Amplifier Circuit Diagram: Here the PCB layout:

Safer Security System Alarm

Here the circuit diagram of safer security system alarm. There are many security systems use a closed loop of wires and switches arranged so that whenever a door or window is opened, the loop will be broken and the alarm will sound. An obvious problem is that someone can tamper with the system, short out… Read More »

15W FM RF Amplifier with 2SC2539

This is a 15W FM RF amplifier circuit which build based on RF Power Transistor 2SC2539. 2SC2539 is a silicon NPN epitaxial planar type transistor designed for RF power amplifiers in VHF band mobile radio applications. FM RF Amplifier Circuit Diagram: Coil Specifications: L1: 2T Coil diameter:4mm L2: in series 6pcs Toroidal ring L3: 4T… Read More »