This circuit could be used for replacing your manual volume control
in a stereo amplifier. In this circuit, push-to-on switch SW1 controls
the forward (volume increase) operation of both channels while a similar
switch SW2 controls reverse (volume decrease) operation of both
channels. A readily available IC from Dallas semiconductor, DS1669 is
used here.
Circuit Diagram:
Parts:
- J1 = RCA Audio Input Socket
- J2 = RCA Audio Input Socket
- C1 = 0.1uF-16V Ceramic Disc Capacitor
- C2 = 0.1uF-16V Ceramic Disc Capacitor
- C3 = 0.1uF-16V Ceramic Disc Capacitor
- IC1 = DS1669 (is available from Dallas SCo.
- SW1 = Momentary Push Button Switch
- SW1 = Momentary Push Button Switch
Notes:
- Replaces mechanical variable resistors.
- Electronic interface provided for digital as well as manual control.
- Wide differential input voltage range between 4.5 and 8 volts.
- Wiper position is maintained in the absence of power.
- Low-cost alternative to mechanical controls.
- Applications include volume, tone, contrast, brightness, and dimmer control.
- The circuit is extremely simple and compact requiring very few external components.
- The power supply can vary from 4.5V to 8V.
- The input signal should not fall below -0.2 volts.
