Redundant clock system utilizing nonsynchronous oscillators
US4254492A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 2, 1979 |
| Grant date | Mar 3, 1981 |
| Priority date | — |
| Expiry date | Apr 2, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A clock system is disclosed having two identical clocks not synchronized with each other. Each of the clocks includes a circuit for selecting the output of one of the clocks as the present system output. Further, each clock includes logic for detecting errors in the operation of itself, and of the other. When an error is detected in the operation of the clock selected to be the present system output, a switchover sequence control switches the output signal of the nonselected clock to become the new system output. The switchover sequence control includes a feature which ensures that the interval between pulses in the system output is greater than a predetermined period in order to minimize detrimental effects on circuitry utilizing the clock system output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.