AC amplifier with automatic DC compensation
US5115205A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1990 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Dec 28, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/217
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An AC power amplifier (50) with a pair of push-pull transistors (Q1, Q2) driving opposite sides (36, 38) of the primary winding of an output transformer (T1) controlled by a pair of variable duty cycle, pulse width modulated width trains (A, B) generated on the output of a pulse width modulator (26) controlled, in turn, through means of a wave shaping feedback system to cause the AC output at the secondary winding (20) to track the output of a precision reference sine wave oscillator (12) and through means of another feedback system for automatic DC compensation including a pair of CMOS analog switches respectively driven by the two pulse width modulated pulse trains (A on 28, B on 30) to produce a pair of feedback signals. A junction (58) couples the pair of feedback signals to form a composite feedback signal and an error amplifier (14) also used in the wave shaping feedback system, responds to the composite feedback signal to balance the duty cycles of the pair of drive signals to reduce the introduction of DC to the output transformer (T1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.