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 »

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 »

15W FM Transmitter using BLY88C

This is long range FM transmitter with transmision power output is up to 15W. This 15W FM transmitter use power transistor BLY88C as the main transmitter amplifier. Building a good FM transmitter(88-110Mhz) begins with getting a good schematic. You don’t have to understand the precise working of the transmitter to build it. But some basic… Read More »

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 »

Mini AM Transmitter

This is the simple and low cost AM transmitter schematic diagram built using transistor BC109C. The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator is built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to 1600KHz. These components can be used… Read More »

NiCd – NiMH Battery Charger

Here is the simple and low cost NiCd and NiMH battery charger circuit which can be used for various battery type and size. This battery charger use a regulator IC of LM317. Schematic diagram: The charge will start if a battery is connected between pins JP1-JP4 or JP2-JP4 or JP3-JP4. For example, if a battery… Read More »