Back to results
US 6,449,217 B1Granted
Low cost clock
AssigneeSiemens Aktiengesellschaft
InventorsPascal Hayet, Alain Sauve
Life of this patent
Estimating the term…
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.
Claims1
A car radio with a clock comprising:
- a low accuracy oscillator that supplies pulses;
- a microcontroller having a high accuracy clock that is used to periodically calibrate the low accuracy oscillator, even when the car radio is in an off state;
- and
- a means for displaying a corrected time.
1 more element
Dependencies are inferred from the claim text.