Apparatus for measuring the characteristics of a wideband electromechanical recording system having a transformer
US4295216A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1980 |
| Grant date | Oct 13, 1981 |
| Priority date | — |
| Expiry date | May 30, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N17/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A monitoring circuit for monitoring and measuring the mechanical characteristics of a piezoelectric video disc recording cutterhead takes the form of a bridge network. The motional charge or motional current, which are related to the mechanical characteristics of the cutterhead, is measured by providing signals of a first polarity to one leg of the bridge and signals of a polarity opposite to the first to another leg of the bridge. One leg of the bridge includes the cutterhead and a sensing capacitor connected in series while the other leg includes the sensing capacitor and a balancing capacitor connected in series. When the capacitance value of the balancing capacitor is properly chosen, the voltage drop across the sensing capacitor is proportional to certain mechanical characteristics of the cutterhead (e.g., displacement).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.