Stereo Digital Volume Control

Here is the circuit diagram of stereo digital volume control. This circuit could possibly be applied for upgrading your manual volume management within a stereo amplifier circuit. In this particular circuit, push-to-on switch S1 controls the forward (volume enhance) operation of the two channels while a identical switch S2 controls reverse (volume reduce) operation of… Read More »

Shortwave (SW) Transmitter with IC BEL1895

Here the SW transmitter circuit based on IC BEL1895. This particular transmitter circuit works in shortwave HF band (6 MHz to 15 MHz), and can be applied for shortrange communication and for educational purposes. The circuit is composed of a mic amplifier circuit, a variable frequency oscillator, and modulation amplifier stages. Transistor T1 (BF195) is… Read More »

USB Powered, Stereo Computer Speaker

This is the circuit diagram of USB powered stereo computer speaker, or it widely known as multimedia speakers for PCs. The circuit has single-chipbased design, low-voltage electrical power supply, compatibility with USB power from computer, simple heat-sinking, inexpensive, large flexibility and wide temperature tolerance. At the heart of the circuit is IC TDA2822M. This IC… Read More »

Low-Cost and Simple Intercom

This is a low-cost and simple intercom circuit design. Some intercom circuits is build by applying integrated circuits. The circuit described right here utilizes 3 certainly transistors which easy to find on the electronic store. Even a newbie can assemble it on a piece of veroboard without difficulty. The circuit consists of a 3-stage resistor-capacitor… Read More »

Basic Dual Polarity Power Supply

This is a very basic dual polarity power supply circuit diagram, it also called symmetrical power supply or split power supply. Basically, it just need the following components: A Center Tapped Transformer Diode rectifier 4 units (or diode bridge 1 unit) Electrolityc capacitor 4 units

Simple Mic Pre-Amp based LM358

Here the simple mic pre-amp circuit design based on single IC LM358. The circuit is very simple, inexpensive and easy to built. This mic pre-amplifier circuit operated with 9V DC voltage, you may use 9V battery for this circuit. Component Parts List: R1, R3, R4 = 10K R2 = 1K R5 = 100K-1M Potensiometer C1… Read More »