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 »

6V to 12V DC to DC Voltage Converter

This is the circuit diagram of 6V to 12V DC to DC voltage converter (6V to 12V DC voltage doubler). This is the active circuit for voltage doubling from 6 volt to 12 volt DC with 1A maximum current. The IC is used as switcher device. Schematic diagram: Components and its usage: IC Switcher/regulator LM2577T-ADJ… 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 »

100W RMS Audio Amplifier

Here is the 100W RMS audio amplifier schematic diagram: This circuit is quite simple but will give you high quality audio output. Take a note that above diagram designed for single input and single output (mono system). For stereo system, you need to build two similar circuits.

2 Watt Mini Audio Amplifier

This is the circuit diagram of 2 Watt mini audio amplifier. This circuit is inexpensive, easy and quite simple. This is general audio amplifier which can be used for computer, CD player or other devices which have headphone output. The circuit was deliberately designed using no ICs and in a rather old-fashioned manner in order… 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 »

13.8 Volt 20 A Transformerless Power Supply

Do you need high current power supply without heavy and expensive transformer? Then, this circuit would be great choice for you. This 13.8 Volt 20 A regulated transformerless power supply. 20A transformer is very-very expensive, large in size and very heavy in weight.


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