Method for controlling a plurality of phase-lock loops from a common frequency control
US5206769A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1992 |
| Grant date | Apr 27, 1993 |
| Priority date | — |
| Expiry date | Apr 6, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/07
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a magnetic tape readback system for a multi-track tape player, a phase lock loop is provided for each of the channel circuits used for reading signals from the respective tracks on a multi-track tape. A common frequency determining capacitor is coupled to all of the phase lock loops such that the frequency of operation of the phase lock loops is stabilized. The capacitor has a capacitance usable in the individual phase lock loops for determining a frequency of operation and it is commonly AC connected to all of the phase lock loops. A capacitance AC couples and DC blocks each of the individual phase lock loops to the frequency determining capacitor such that the individual phase lock loops have their own reference DC levels and yet receive AC input from all of the other phase lock loops.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.