Variable / Adjustable DC Power Supply 1.2V – 25V using LM338K

This is variable DC power supply circuit, or we can call it adjustable DC power supply which give us a 1.2V-25V output voltage. The power supply schematic above is taken from the datasheet of regulator LM338K manufactured National Semiconductor. The circuit uses IC LM338K as the voltage regulator, so we will get the stable and… Read More »

6-12V Variable Regulated Power Supply

This is an adjustable / variable power supply which have adjustabled output voltage from 6-12 DC volt. This power supply can be used for general circuit or gadget which require 6 – 12DC voltage to work. Component Parts List: T1 = primary 115[220]/secondary 8 VAC transformer. Center Tap not needed. Q1 = 2N1613, NTE128, or… Read More »

Bench Power Supply I

This is bench power supply circuit for multi purpose usage… This bench power supply features three solid-state DC power supplies. The first supply gives a +1.5 to +15 volts at 1 ampere. The second supply gives a -1.5 to -15 volts at 1 ampere. The third has a fixed 5V at 3 amperes. All  DC… Read More »

3V-30V/3A Adjustable Regulated Power Supply

The circuit diagram of 3V-30V/3A adjustable regulated power supply. This is an adjustable and regulated power supply with stabilized DC voltage between 3V and 30V provided that the consumption does not exceed 3A direct current. This circuit featured with short circuit protection and overload protection. This power supply unit can be used for general purposes,… 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 »

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.

Stereo Tone Control with Line In + Microphone Mixer

This is an active stereo tone control circuit using very well known op-amp IC of TL072. The circuit include mic pre-amp and mixer control. In this design, we have two inputs: one for line (stereo), one for microphone and has control of the three audio frequency (high/treble, medium and low/bass). It also provide balance control… 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 »