Digital Volume Control Circuit
All audio amplifiers have some mechanism to increase and decrease volume. Most such mechanisms involve mechanical parts like a potentiometer. Here this project is to create an audio controller which works digitally. This is a very simple project which uses two switches and an IC to electronically control the audio output from an amplifier.
This is the circuit diagram of a digital volume controller for any sort of audio amplifiers or almost any circuit where a mechanical potentiometer is there(conditions apply). Simple and low cost, the heart of the circuit is DS 1669 digital potentiometer IC from Dallas Semiconductors. The circuit has no external components other than two pushbutton switches and a capacitor.
S 1 increases the volume & S2 decreases.
The input audio signal must be not less than -0.2 Volts.
If some clipping problem occurs, use a dual power supply of +5 & -5V.( Not shown in the figure).In this situation connect +5V to pin 8 & -5V to pin5 of IC DS1669.
Volume controller Circuit Diagram
Pin assignment & description of DS1669
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