An analog electronic timepiece powered by a battery, which prevents malfunctions of the divider circuits within the timepiece during periods of high load is provided. An oscillator circuit produces a high frequency time standard signal. A divider circuit divides the high frequency time standard signal to a low frequency time standard signal. An analog display means provides a visual indication of the time. A drive circuit including a drive coil and a motor is coupled to the divider circuit and analog display means and produces drive pulses in responses to the low frequency drive signals to drive the analog display means. The DC resistance of the drive coil is at least twice as great as the internal resistance of the battery. A first time constant of the battery associated with the reduction of battery output voltage during driving pulses and a second time constant associated with restoring battery output voltage after the driving pulse are both greater than 200 msec when the internal resistance of the battery is greater than 100.OMEGA.. A regulating circuit coupled to the battery, oscillator circuit and divider circuit receives the battery output voltage and outputs a regulated voltage to the oscillator circuit and divider circuit.

Disclosed is an integrated circuit which comprises: a constant voltage circuit including a reference voltage generator, a feedback amplifier, a differential amplifier having an input for receiving an output signal of the reference voltage generator as a reference signal and another input for receiving an output of the feedback amplifier as a negative feedback signal, and a monochannel output driver driven in accordance with an output of the differential amplifier; a circuit load connected to an output of the constant voltage circuit; and an MOS transistor connected in parallel to the circuit load and arranged so as to be driven when a heavy load is periodically driven. The MOS transistor is turned on in a heavy load operation to thereby rapidly discharge a charge in the capacitance of the constant voltage circuit and a charge in the capacitance in the circuit load are rapidly discharged so that an output of the feedback amplifier is made to cope with the fluctuation in voltage, whereby the mono-channel output driver in the output stage is properly controlled to suppress the fluctuation in output even when a power source fluctuates.

A timepiece includes in addition to the conventional timekeeping circuits, high load, that is, high current circuits such as an alarm driving circuit and a lamp driving circuit. Low load, small current systems such as the oscillator, divider, display drivers and display for timekeeping are operated directly from the battery voltage source when the high load circuits are off. When the high load circuits are on, the low load circuits are disconnected from the battery and operate from an electric charge stored in a capacitor connected in parallel with the low load circuits. The high load circuits are driven intermittently at a high frequency to reduce power consumption and to permit recharging of the storage capacitor during off-periods. The drive frequency is sufficiently high such that an illumination lamp shows no flicker and brightness is controlled by duty cycle.

An electronic circuit, having a load circuit driven by a battery, includes a voltage drop circuit to provide a constant dropped voltage even when the battery weakens and the load is activated. During load circuit activation, the dropped voltage is provided by two capacitors in the voltage drop circuit which are charged only during the non-drive period of the load circuit.

A heavy-load driving device for a electronic watch is provided that assures reliable timekeeping operation and enables proper drive in accordance with the power supply voltage level. When drive command circuit generates an alarm-coincidence signal Sa, this signal Sa causes a preparatory judging circuit 10 to operate, so as to make a judgment, in accordance with the reduced power supply voltage level under a given load condition, as to whether or not to allow drive of a beeper device 31, a drive-enabling signal Svm being output if the judgment is to allow drive. By doing this, a heavy-load voltage detection circuit 21 starts to output a drive-time judgment signal Pvh which indicates the power supply voltage level judgment results. By means of the Svm signal, the a drive-signal control circuit 23 begins to operate, and at a drive condition selection circuit 25, in accordance with the signal Pvh, successive selection is made of a drive signal to be supplied to the beeper device 31 from the plurality of drive signals B75, B50, and B25 which are generated by the a drive-signal generating circuit 16, the selected drive signal driving the beeper device 31.