Negative impedance driving apparatus having temperature compensation circuit
US4980920A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Oct 13, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/369
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A driving apparatus for negative-impedance driving a speaker as a load, comprises a detection element, a positive feedback circuit, a temperature compensation circuit, a sensor element, a control circuit, and an input f characteristic control circuit. The resistor as the detection element connected in series with the load detects a current flowing through the load. The feedback circuit feeds back a detection output of the detection element to an input side of the driving apparatus. The temperature compensation circuit controls the negative-impedance driving state to compensate for an increase in load impedance upon an increase in temperature of the load. The sensor element detects that a temperature of the load reaches a predetermined value. The control circuit stops temperature compensation of the temperature compensation circuit or decreases a degree of temperature compensation in accordance with an output from the sensor element. The input f characteristic control circuit controls frequency characteristic of an input signal in accordance with an output from the control circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.