Wide frequency deviation voltage controlled crystal oscillator having plural parallel crystals
US5229735A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1992 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Mar 30, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/545
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A wide frequency deviation voltage controlled crystal oscillator includes a multiple section bandpass filter containing a plurality of crystal or ceramic elements. One embodiment includes a plurality of crystals which are connected into parallel conduction paths. The crystals have resonant frequencies which are separated by small, selected intervals so that the oscillator may be adjusted to a wider range of frequencies than prior art oscillators. Alternatively, the same result may be achieved by using crystals with the same resonant frequency and connecting each crystal to a capacitor having a selected value. In another embodiment a multiple section crystal or ceramic bandpass filter is substituted for the parallel conduction paths. The principles of the invention are applicable to a number of different devices, including the ringing circuits used in color televisions to perpetuate the color bursts which appear in the blanking intervals of the incoming TV signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.