Processor control of an audio transducer
US7505600B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 2005 |
| Grant date | Mar 17, 2009 |
| Priority date | — |
| Expiry date | Nov 6, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B3/10
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A controller, either a microprocessor or finite state machine, is used to generate a pulse train whose frequency and duty cycle can be varied to alter the frequency and amplitude of the output of a driven audio transducer. The ability to control both frequency and amplitude allows programmatic synthesis of many audio effects such as steady tones, warbles, beeps, sirens and chimes with no hardware or circuit changes. The transducer can be a piezoelectric bender or a speaker. The output of the controller controls a switch that builds current in an inductor when the switch is on. When the switch is turned off, the energy stored in the inductor is dumped into the audio transducer, either directly or through intermediate capacitor storage. This allows the generation of voltages across the transducer many times the supply voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.