Temperature compensated electronic timepiece

An electronic timepiece comprising:

• an oscillator having an output frequency variable with temperature and forming a time reference signal generator for generating a time reference signal at the oscillation frequency;
• a time-count unit-signal former connected to said generator for dividing said time reference signal to form time-count unit-signal;
• a time counter for counting said time-count unit-signals to form a time-indicating signal;
• a display connected to said counter for providing a visual representation of time in response to said time-indicating signal;
• a temperature compensating device connected between the time reference signal generator and the time count unit-signal former for receiving a signal from the time count unit-signal former;
• the temperature compensating device having a temperature sensitive means, a voltage generator, a coded signal generator, a temperature coded signal discriminator, a frequency control circuit, and a frequency addition circuit;
• in the temperature sensitive means the emitter of a transistor is connected to one electrode of a constant voltage supply source and the collector is connected through a resistor to the other electrode of said constant voltage supply source and delivering a digital signal reversed from an initial state if the base-emitter voltage of the transistor becomes equal to the threshold value of the transistor at a given temperature when the change of a voltage-current characteristic is effected by the temperature change at the base-emitter junction;
• the voltage generator for supplying different voltages to the base-emitter of the temperature sensitive device by changing-over with an electronic switch such as a transmission one wherein a resistor is connected in series between one and the other electrodes of the said constant voltage supply source;
• the coded signal generator comprising a shift register receiving an input clock signal from the time-count unit-signal former, controlling the electronic switch of the voltage generator and delivering a signal as the standard of a temperature coded signal;
• the temperature coded signal discriminator discriminating the temperature coded signal from the output signal of the temperature sensitive means and that of the coded signal generator by an NAND gate and memorizing it until the next temperature coded signal;
• the frequency control circuit forming a thin pulse from the output of the temperature coded signal discriminator and that of the time-count unit-signal former;
• and
• the frequency addition circuit comprising an EXCLUSIVE-OR GATE circuit adding the output signal of the frequency control circuit to the time reference signal generator, whereby it compensates the change of the oscillating frequency in the time reference signal generator caused by the temperature change.