Dual Output Stabilized Power Supply

This is a dual regulated and stabilized power supply, usually used to supply amplifier circuit, it also known as split powersupply. There are 3 output that are (+) voltage, (0) Ground (normal), and (-) voltage. The current output max about 0.3-0.5 A. For higher current output, power transistor is needed. Please take a note that… 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 »

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.

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 »

Active Speaker Protector

This is a simple active speaker protector circuit which has a very important use, expecially to protect the loudspeakers of a audio system. It prevent the speaker from noise sound when we turn on the power amplifier. The circuit drives the speakers after 3 to 10 seconds so that the source of the same stabilizes… Read More »

5 Band Graphic Equaliser Project

Equaliser circuits typically divide the audio spectrum into separate frequency bands and have independent gain control for each band. The output of each band is mixed at IC4(A) and then fed to an audio power amplifier. Proper quality factor (Q) needs to be selected to avoid overlap in adjacent bands as this introduce colouration into… Read More »

Electronic Quiz Button Table

This is the circuit diagram of electronic quiz button table. This circuit is simple, easy to built and of course it is not expensive. This quiz circuit used for four game participants. It determines the contestant who first presses the switch (S1 through S4) to answer a question and locks out the remaining three entries… Read More »