TIMER CIRCUIT AND WARNING DEVICE

PROBLEM TO BE SOLVED: To provide a timer circuit for achieving accurate time-measurement even by using an oscillation part whose oscillation frequency fluctuates according to a power supply voltage and a warning device using the timer circuit. SOLUTION: A control part 14 decides the lapse of a unit time each time an oscillation circuit 14a outputs a pulse only by the number of unit counts. Also, the control part 14 acquires voltage correction coefficients based on the output of a voltage detection part 15 which detects the output voltage of a primary battery BT being a power source, and acquires temperature correction coefficients based on the output of a temperature detection part 16, and multiplies the number of reference counts being the number of unit counts in a predetermined standard state by each acquired coefficient to acquire the number of new unit counts. The change of the number of unit counts offsets influence on the unit time due to the fluctuation of an oscillation frequency accompanied by the fluctuation of the output voltage or the fluctuation of a temperature of the primary battery BT. Thus, it is possible to make almost constant the unit time acquired by using the number of new unit counts regardless of the fluctuation of the oscillation frequency. COPYRIGHT: (C)2009,JPO&INPIT