Audio power amplifier
US9190960B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 2014 |
| Grant date | Nov 17, 2015 |
| Priority date | — |
| Expiry date | May 23, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/541
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Improvements to U.S. Pat. No. 5,428,642 including use of a single clock providing a first frequency to drive a power supply and a second frequency, twice the first frequency, to dual channel pulse width modulators and audio amplifiers. The power supply is improved to provide enough output voltage that the amplifier stays below 90% modulation and the first frequency driver eliminates the dead band, thereby improving efficiency. Current limiting, even against shorts in the load, is provided by inductor inputs to the clipper circuits, where the inductors are in the magnetic fields of the output chokes. The audio amplifiers are isolated by optical couplers for the audio signal and by an optical coupler and isolation transformers for the clock. One clock amplifier supplies both amplifier channels. The pulse width modulator uses the optically isolated clock and receives clipped audio directly. Two channels fit in the space of one old channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.