Browse Prior Art Database

APPARATUS WITH TWO STEP VOLUME CONTROL

IP.com Disclosure Number: IPCOM000006535D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2002-Jan-11
Document File: 1 page(s) / 46K

Publishing Venue

Motorola

Related People

John K. Gleeson: AUTHOR [+2]

Abstract

A simple, cost effective, volume control can be built for most electronic devices. Many consumer electronic products have adjustable controls for setting the vol- ume of a loudspeaker or transducer. These controls are usually expensive mechanical switches or potentiome- ters. However, switches and pots are notoriously unreli- able when used in harsh environments. Reliable electronic controls have been used in other applications, like VCR remotes, but the process of changing the volume setting can take several seconds.

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MOTOROkA INC. Technical Developments Volume 16 August 1992

APPARATUS WITH TWO STEP VOLUME CONTROL

by John K. Gleeson and Christopher G. Hem

  A simple, cost effective, volume control can be built for most electronic devices. Many consumer electronic products have adjustable controls for setting the vol- ume of a loudspeaker or transducer. These controls are usually expensive mechanical switches or potentiome- ters. However, switches and pots are notoriously unreli- able when used in harsh environments. Reliable electronic controls have been used in other applications, like VCR remotes, but the process of changing the volume setting can take several seconds.

A simpler control can be constructed by limiting

the device to two volume settings. For example, a device might be preset to tnaximum volume but would imme- diately toggle to the lower audio level when a switch is closed. This type of control combines an elastomeric pushbutton with a switching circuit to control the audio loudness. Elastomeric switches are preferred due to their low cost and excellent water sealing properties. The switching circuit can be as simple as a latch and a single transistor switch. Figure 1. shows a two step volume control for use in a microprocessor controlled device. The actual volume control is implemented as shown in Figure 2.

I

Uicrocomputer 1

Figure

   I to ----I Audio Amp

digital control

I = low volume 0- high volume

Figure

2.

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