JPS55149090A - Temperature compensating system of crystal watch - Google Patents

Abstract

PURPOSE:To make possible rapid and accurate temperature compensation by counting the half periods of beat signals, and forming the pulse of the period proportional to the square of the count value thereof as a compensating pulse in a twin-quartz temperature compensating system. CONSTITUTION:The oscillation signals of main- and sub-crystal oscillators 51, 53 are applied to a beat circuit 53 and the half periods of the beat signals are counted by the 1st counter 57 which counts the divided clocks from a divider 55. When the count value thereof becomes the count value N or more of a preset counter 56 which counts the set number of the outputs of the oscillator 51, the 2nd counter 58 is reset and the 3rd counter 59 generates one correcting pulse of a small period of the width proportional to the square of the count value N. This pulse is applied to an interrupt circuit 54 to temperature-compensate the output of the oscillator 51. The rapid and accurate temperature compensation corresponding to the beat signals of relatively less change rates is accomplished by this one pulse correction of a small period and high frequency.