Abstract: Provided is an electronic watch capable of, even if an indicating hand having a large moment of inertia is used, accurately determining success and failure of rotation. The electronic watch detects rotation by using a first detection mode determination circuit (12) and a second detection mode determination circuit (13). In the electronic watch, a timing counter (14) for measuring a time after an output of a normal drive pulse is followed by a detection pulse selection circuit (151) provided as changing means for changing a width or a frequency of a detection pulse in accordance with an output time of the detection pulse. The detection pulse detects the rotation and simultaneously serves as an electromagnetic brake for a rotor (10). The electromagnetic brake for the rotor (10) is controlled by changing the width or the frequency of the detection pulse in a predetermined period, thereby achieving an accurate rotation detection.

Abstract: A step motor control device detects a rotational driving state of a step motor. In a first detection period immediately after termination of the rotational driving state of the step motor, selected switch elements are controlled so that a first detection signal is obtained. If the step motor is not in a rotational driving state, the first detection signal is suppressed to a low voltage that is equal to or lower than a threshold value. In a second detection period immediately after lapse of the first detection period, selected switch elements are controlled so that a second detection signal of high and stable voltage is obtained in accordance with the rotational driving state of the step motor.

Abstract: A control device detects a rotational driving state of a step motor having a coil. First and second switch elements are connected to each other in series, and a node of the first and second switch elements are connected to one side of the coil during use of the control device. Third and fourth switch elements are connected to each other in series, and a node of the third and fourth switch elements are connected to the other side of the coil during use of the control device. A first series circuit has a fifth switch element connected in parallel with the first switch element. A second series circuit has a sixth switch element connected in parallel with the third switch element. A control section controls an on/off operation of the third switch element at a given frequency after a given period has elapsed in a state where the fourth and fifth switch elements are turned on.

Abstract: Within a semiconductor device having two sets of CMOS inverters, the two sets of CMOS inverters are electrically connected in series to a power source for supplying electric power to the semiconductor device. The two sets of CMOS inverters are formed in an oscillating circuit for producing a time base signal and a frequency dividing circuit, respectively. Device operating current and power consumption are accordingly reduced.

Abstract: A d-c converter for inclusion in a miniature electronic device, such as an electronic wristwatch having a d-c supply source, the converter functioning to increase or decrease the voltage of this source. The converter includes a transformer whose primary is connected to the source through a periodically-actuated chopper to produce an alternating voltage, the secondary of the transformer being connected to a rectifier circuit having at least one controllable switch element whose on-off state is governed in synchronism with the chopper whereby the switch element acts to rectify the secondary voltage.

Abstract: An electronic timepiece comprising a quartz crystal oscillator for producing a time standard signal, a frequency divider, and a display driver. The electronic circuit comprises a digital logic circuit employing a complementary MOS integrated circuit (CMOS.multidot.IC). A diffusion resistor is formed in the N-type substrate of the CMOS transistor of the CMOS.multidot.IC by diffusing an impurity at the same time with the diffusion of the P-well for the N-channel MOS transistor of the CMOS transistor. Supply voltage of a battery is supplied to a part of the CMOS.multidot.IC through the diffusion resistor, whereby variation of the threshold voltage of the CMOST may be compensated.

Abstract: A power consumption reduction device in an LSI device is disclosed which includes a liquid crystal display drive circuit. The liquid crystal enabling voltage generator including bleeder resistors and adapted for generating three voltage levels is provided with means for shutting down current paths via the bleeder resistors.

Abstract: A crystal oscillation-type electronic timepiece having an oscillator with a crystal oscillator as a time base, means for dividing the frequency of the oscillator, display driving means and time display means. The oscillator has a complementary metal oxide semiconductor logic circuit including an inverter with a gated N-channel transistor and a gated P-channel transistor. The inverter is designed such that a ratio of the width and length in a channel of the gated N-channel transistor is made less than one and that a ratio of the width and length in a channel of the gated P-channel transistor is made less than two. The capacity of an input capacitor connected to an input of the crystal oscillating element is larger than that of an output capacitor connected to an input of the crystal oscillating element. The consumed power at the oscillating part is thereby decreased.

Abstract: An electronic timepiece circuit is provided with an oscillator for producing a reference signal and a frequency dividing circuit which frequency-divides the reference signal from the oscillator to produce a signal with given time intervals. Clock data stored in the memory is read out therefrom by a timing signal corresponding to the output signal from a given stage of the frequency dividing circuit and is loaded into a shift register where it is stored temporarily. The clock data stored in the memory is read out therefrom at given time intervals by a control signal obtained in accordance with the output signal from a given stage of the frequency dividing circuit, and the read out clock data, together with the clock data read out to the shift register, is subjected to a given operation, with the result that the clock data is updated. The updated clock signal is loaded into the memory by a control circuit.

Abstract: An integrated control device for controlling a device such as a LED display or a miniature stepping motor for an electronic watch comprises at least one insulated-gate field effect transistor for controlling the supply of current to the element. The gate of the F.E.T. is connected to a control circuit including a voltage multiplier comprising a series-connected chain of rectifiers and a plurality of capacitors connected between the respective junctions between rectifiers and alternate inputs. High frequency signals of opposite phase are supplied to the inputs under control of an input control signal. Circuit means are provided for starting the action of the voltage multiplier at the beginning of an input control signal and for short-circuiting the output of the control circuit at the end of an input control signal.

Abstract: Adjustments in a miniature electronic device are rapidly accomplished through electronic switching using non-volatile semiconductor memory elements which memorize the amount of an adjustment. Adjustments are accomplished by the application of positive or negative voltages.

Abstract: IC input circuitry particularly suited for use in an electronic wristwatch or other small-sized electronic instrument is provided. Each input stage is adapted to receive at least one input. An input terminal is provided for each input stage in order to receive a two-state input signal. An impedance element is disposed intermediate each input terminal and a reference voltage, in order to distinguish between respective states of the input signal. The invention is particularly characterized by gating circuitry for producing a gating signal having a predetermined time interval, and a memory, coupled to each input terminal and impedance element coupled thereto, for selectively storing the state of the input signal applied to the input terminal and discriminated by the impedance element, during the predetermined time interval of the gating signal.

Abstract: A semiconductor integrated driving circuit including a junction FET and a C-MOS FET fabricated on a common semiconductor substrate. The junction FET is switched between conductive and non-conductive states for controlling and supplying a high driving current to a high current load element.

Abstract: A step motor driving and control mechanism for use in an electronic timepiece for reducing the current consumption thereof is provided. Load detection circuitry detects the load condition of the step motor by detecting the signals induced in the drive coil of the step motor after each stepping of the rotor. The load detection circuitry selectively produces a load condition signal in response to detecting current peaks representative of a predetermined load condition of the step motor. The load detection circuitry is characterized by the use of MOS transistors therein for accurately detecting the occurrence of the current peaks. Driving and control circuitry is provided for receiving a low frequency timekeeping signal produced by a divider circuit and a load detection signal, when same is selectively produced by the load detection circuitry.