Low cost clock
US6449217B1 · kind B1 · utility
1Cited by
6References
1Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1999 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Sep 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04G3/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A time display is comprised of a low cost low accuracy RC oscillator. A series of pulses derived from this oscillator, for example, with a period of 1 second, is used for controlling a diode. An accurate time-display function of a car radio is also derived from this oscillator. This is possible as the main micro-controller periodically calibrates the low accuracy oscillator using a high accuracy crystal clock. Specifically, it measures the PC oscillator period in order to correct, in the micro-controller, the time issued from the RC oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.