摘要:
Die Erfindung betrifft eine Referenzuhr mit einer internen Echtzeituhr mit hochstabilem Taktgenerator, deren interne Systemzeit kontinuierlich mit den vom jahreszeitlich bedingten Sonnenstand abhängigen Sonnenaufgängen und Sonnenuntergängen synchronisiert wird. Zusätzlich wird die beispielhafte Anwendung der erfindungsgemäßen Referenzuhr in einer Vorrichtung zur temporären Leistungsreduzierung von zentralgesteuerten Leuchten beschrieben.
摘要:
The invention relates to a timepiece device (1), in particular for a vehicle, comprising a control unit (2) for time keeping, which is synchronizable by a clock generator. Thereby the timepiece device (1) having at least two crystal oscillators built respectively by at least one crystal unit (3.1, 3.2), whereby a first crystal oscillator with a first crystal unit (3.1) and with a predetermined nominal oscillation frequency is suitable for use as the clock generator of the control unit (2) during a vehicle standby mode, and whereby the oscillation frequency of the first crystal oscillator is at least temporarily measured and adjustable by a second crystal oscillator with a second crystal unit (3.2) whose nominal oscillation frequency is higher than that of the first crystal oscillator. Further the invention relates to a method of operation of the timepiece device (1), whereby the oscillation frequency of the second crystal oscillator is compensated against the temperature by the software inside the control unit (2).
摘要:
A method for temperature compensation of a time basis, driven by a quartz crystal oscillator, comprises a second oscillator having a linear frequency dependency on temperature. The method counts the pulses (65) of the quartz crystal oscillator for at least three different temperatures during time intervals (62, 63..) given by a predetermined number of pulses (61) of the second oscillator. Then the function of variation of the second oscillator period with temperature is calculated based on said three pulse count values. Then said calculated function is used to correct the frequency change of the quartz crystal oscillator due to temperature changes at any operating temperature. Therefore the temperature correction can be provided independently from any offset considerations and is not dependent on the choice of the three different temperatures.
摘要:
A method for correcting time error in an oscillator operated clock according to one aspect of the invention includes at selected times determining at least one of a time error in the clock and a frequency difference between the oscillator and a reference oscillator by detecting a time reference signal. A change in the at least one of the time error and the frequency difference between a first one and a second one of the detecting the time reference signals is determined. A frequency of the oscillator is adjusted so as to substantially cancel a cumulative time error between the second one of the detecting the time reference signal and a selected detecting the time reference signal.
摘要:
An electronic circuit has a supply voltage generation circuit (100) and a crystal oscillation circuit (10) driven the supply voltage generation circuit (100). The supply voltage generation circuit (100) comprises: a first voltage generation circuit (110) for creating a reference voltage (Vref1), and a second voltage generation circuit (130) for creating said supply voltage (Vreg) to have a predetermined relationship with said reference voltage (Vref1). The second voltage generation circuit (130) comprises: a differential amplifier (140) for amplifying the difference between said reference voltage (Vref1) and a comparison voltage (Vref2); a constant-current source (150-2); a circuit having a voltage-control transistor (132) to which the constant current of said constant-current source (150-2) is supplied, and which has one end connected to said constant-current source (150-2); and an output transistor (134) which is connected between another end of said voltage-control transistor (132), and a circuit node being at a predetermined second potential, the resistance of said output transistor (134) being controlled by the output of said differential amplifier. The comparison voltage (Vref2) is output from said one end of said voltage-control transistor (132), using a first potential as reference, while said supply voltage (Vreg) is output from said other end of said voltage-control transistor (132). The constant current is set to a value within a saturated operating region of the voltage-control transistor (132), so that the sum of the magnitude of variation of potential difference between said comparison voltage (Vref2) and said supply voltage (Vreg) which are potentials at respective ends of said voltage-control transistor (132) with a variation of temperature within a guaranteed operating temperature range and one of the magnitude of variation of said reference voltage (Vref1) of said first voltage generation circuit (110) with a variation of temperature within a guaranteed operating temperature range and the magnitude of variation of said comparison voltage (Vref2) of said voltage-control transistor (132) with a variation of temperature within a guaranteed operating temperature range, is the same as the magnitude of variation of an oscillation-stopping voltage Vsto of said crystal oscillation circuit (10) with a variation of temperature within a guaranteed operating temperature range.
摘要:
A method for temperature compensation of a time basis, driven by a quartz crystal oscillator, comprises a second oscillator having a linear frequency dependency on temperature. The method counts the pulses (65) of the quartz crystal oscillator for at least three different temperatures during time intervals (62, 63..) given by a predetermined number of pulses (61) of the second oscillator. Then the function of variation of the second oscillator period with temperature is calculated based on said three pulse count values. Then said calculated function is used to correct the frequency change of the quartz crystal oscillator due to temperature changes at any operating temperature. Therefore the temperature correction can be provided independently from any offset considerations and is not dependent on the choice of the three different temperatures.
摘要:
The temperature compensated timing signal generator comprises a crystal oscillator (12; 112) configured to generate a reference time signal, and a divider circuit (14, 114) arranged to receive the reference time signal as input and to output a coarse time unit signal, the coarse time unit signal having an actual frequency deviating from a desired frequency as a function of temperature of said crystal oscillator. The signal generator also includes a high frequency oscillator (16; 116) configured to generate an interpolation signal having a frequency (f RC ) greater than the frequency (f XT ) of the crystal oscillator. A finite state machine (24; 124) computes a deviation compensating signal as a function of the temperature signal, the signal comprises an integer part representative of an integer number of pulses to be inhibited or injected in the divider circuit (14; 114) and a fractional part representative of how much the output of a new time unit signal pulse should further be delayed in order to compensate for any remaining deviation.