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 »

Electronic Siren

This is Electronic Siren circuit diagram which use standard discrete components. The sound produced imitates the rise and fall of an American police siren. When first switched on the 10u capacitors is discharged and both transistors are off. When the push button switch is pressed to 10u capacitor will charge via the 22k resistor. This… Read More »

Portable Audio Amplifier

This is simple portable audio amplifier circuit. This circuit built based on IC TEA2025 which is a monolithic integrated audio amplifier in a 16-pin plastic dual in line package manufactured by UTC. Circuit has Internal Thermal Protector. It is designed for portable cassette players, mp3 players and radios. You can also use it as your… Read More »

Basic Inverter

The following diagram is the basic design diagram of inverter circuit. The circuit will convert 12V DC to 120V AC. This basic inverter circuit can handle up to 1000Watts supply depends the T1, T2 and transformer used. Please see the note. Basic Inverter Components list: Part Total Qty. Description Substitutions C1, C2 2 68 uf,… Read More »

Basic UPS Circuit 5V and 12V DC

The above diagram is a basic Uninterupted Power Supply (UPS) circuit. This basic UPS circuit is a very simple and inexpensive. This circuit can be adapted/modified for other regulated and unregulated voltages by using different regulators and batteries. For a 15 Volt regulated supply, you may apply two 12V batteries connected in series (it will… Read More »

25W HiFi Audio Amplifier with MOSFET

This is high fidelity, high quality 25W HiFi audio amplifier circuit delivers great audio performance. You don’t need pre amplifier circuit for this design since it can be directly connected to the input devices such as computers, phones, radios, TVs, etc. Component list: R1,R4 = 47K 1/4W Resistors R2 = 4K7 1/4W Resistors R3 =… Read More »

20 Watt Audio Amplifier with LM1875

This is 20 watt audio amplifier circuit design which use IC LM1875 as main component. This circuit is simple and very easy to built. For stereo channel, you need to build the two same circuits which will amplify the both of audio channels (right and left channel). Dual polarity / symmetrical power supply required for… Read More »