An electronic timepiece such as a wrist watch of the type employing all solid state components including an electronic or a liquid crystal output display for indicating time, utilizes a high efficiency up-converter to enable a small physical and low voltage battery to provide energy for the entire electronic watch assembly by applying said battery voltage to an inductor which conducts current under control of a switching circuit. The control of current through the inductor at specified intervals causes a high voltage pulse train to be developed which is then rectified to provide a higher DC voltage for providing operating potential for the entire electronic assembly of the timepiece. The stability of the voltage output can be enhanced by means of a feedback regulator.

A circuit in an electronic timepiece including a battery, a crystal oscillator, a frequency divider, a display driver and a display for reducing the magnitude of the voltage to one or more of the oscillator or driver circuits after the timepiece is turned on. The circuit initially allows the magnitude of the voltage applied to be the same as that of the battery. After some predetermined time has elapsed, the circuit reduces the applied voltage thereby reducing the power consumption and extending battery life.

An electronic timekeeping device includes bipolar integrated circuit implemented logic in combination with a liquid crystal display. The bipolar circuitry is configured to effectively implement logic functions with a supply voltage of 1 volt. Drive circuitry is coupled to the liquid crystal display to effectively impress an a.c. voltage across the liquid crystal cell. Logic of the drive circuitry is effective to provide out of phase voltages across the liquid crystal cell when display is required. When display is not required the voltages across the liquid crystal display cell are in phase such that effectively no potential difference is generated across the liquid crystal material.

A step motor in a horological device is connected in a control circuit such that the motor is fed by a battery under the control of a reference oscillator, a frequency divider, a power stage and a shaper. The power stage comprises MOS power transistors exclusively of N-MOS type connected in pairs such that one transistor has its emitter connected to one terminal of the battery and its collector connected to one terminal of the motor coil and to the emitter of the second transistor, whereas the second transistor has a collector connected to the other terminal of the battery. The shaper delivers voltage to the power transistors via a voltage booster in the form of a capacitor so that the control pulses are of a voltage much higher than the voltage of the battery itself. When the motor is of bi-polar type a second pair of power transistors is connected to the other terminal of the coil in similar fashion.

An electronic timekeeping device includes bipolar integrated circuit implemented logic in combination with a liquid crystal display. The bipolar circuitry is configured to effectively implement logic functions with a supply voltage of only one volt. Drive circuitry is coupled to the liquid crystal display to effectively impress an a.c. voltage across the liquid crystal cell when display is required. The logic circuitry includes a transistor configured current source regulated to effectively maintain a current independent of source and load variations, enabling integrated circuit implementation without utilizing large value external resistors. The display circuitry includes logic for enabling display of the calendar date and time, reset capabilities independent of date increments are provided.