Active DC Voltage Doubler

Here is the circuit diagram of active DC voltage doubler which used to increase the DC voltage. This circuit drives relays of 24 and 18VDC from a 12V power supply. Use this circuit can be work with almost any PNP or NPN power transistor, of course the transistor with specific characteristic similar to the transistor… Read More »

100W Audio Amplifier with Transistor BDW83D/BDW84D

Here is the circuit diagram of 100W audio amplifier which using power transistor BDW83D and BDW84D for the final amplification. It uses dual polarity power supply to work. Copyright belong to Smart Kit. The circuit should be seen like this: This is an exceptionally well designed amplifier, with a lot of power reserve, high fidelity,… Read More »

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 »

35W Tube Power Amplifier with EL34

This is the circuit diagram of 35W Tube Power Amplifier with EL34. This tube amplifier designed in 1953 and worked from 1954 until 1989. If you’re interested with classic circuit and classic components, then you should try this circuit. The circuit is interesting but i think it is hard to find the tubes. Schematic Diagram:

0-30V Stabilized Variable Power Supply with Current Control

This is high quality 0-30v stabilized variable power supply circuit diagram. You will able to adjust the output voltage from 0 volt up to 30 volt DC. You also able to adjust the current output value from 0.002 A to 3 A. This variable power supply incorporates an electronic output current limiter that effectively controls… Read More »

Small Sound Amplifier for Ears (Hearing Aid)

This is the simple project of small sound amplifier for ears or often called hearing aid device or hearing loss amplifier. This circuit was already tested on some patients and give significant improvement in the hearing ability to the patients. It consumes a very small amount of power within the range of 10 milliwatts. Furthermore,… 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 »

Galaxy Audio Booster using RC4558

The following is an electronic circuit called galaxy audio booster which serves to improve the performance of your audio system. This circuit uses an IC RC4558 in which there are two op-amp modules that can be used for stereo audio applications. The circuit is similar to stereo tone booster that uses the principle of High… Read More »