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 »

1.5 Watt FM Transmitter

This is a simple, well designed 1.5 Watt FM Transmitter circuit using power transistor 2N2219A. This circuit should be able to cover 1-2 KM range. It use +5-30V power supply to work. Refer to the above diagram, the input source is an electret condenser microphone (you may try to  use other input sources) and signal… Read More »

Sound Effects Generator (8 different sound) based IC HT2884

This is the circuit diagram of sound effects generator. All sounds in this circuit are generated by HT2884. The HT2884 is a CMOS LSI chip equipped with tone circuit, noise circuit, and other control logic to generate various sounds to be used in sound effects production. This IC features: single power supply (2.4V – 3.3V),… Read More »

LED Flashing Heart

This is the LED flashing circuit, since the shape used in this circuit was hearth shape, then we call it LED flashing heart circuit. The circuit is quite simple, low cost, easy to built. Alternatively, you could be create another shape, not just heart shape. Schematic diagram: Component list: Resistors R1, R2 – 470 ohm,… Read More »