Speaker volume control apparatus and method
US4797932A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1987 |
| Grant date | Jan 10, 1989 |
| Priority date | — |
| Expiry date | Nov 23, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/165
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Apparatus and method for establishing and changing the volume level of a tone generator which may be used in connection with auditory feedback in a point of sale terminal or other business machine include a microprocessor having a timer with two settable registers which can be set to establish the duty cycle of a signal, an inverting buffer coupled to the timer output, an integrating circuit to which the signal from the buffer is applied, a transistor driver for a speaker to which the integrated signal is applied, and the speaker, the volume of the tone of which may be changed by altering the relative counts of the two timer registers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.