An oscillator circuit includes: a charge and discharge circuit for charging or discharging a capacitor; and a signal generating circuit for generating a signal in which (i) an interval time period indicative of a cycle on which cycle a receiving device performs a periodical intermittent operation and (ii) a watch time period indicative of a time period during which the receiving device performing the periodical intermittent operation is in an ON state are set based on a charge and discharge signal which varies according to charging and discharging of the charge and discharge circuit with respect to the capacitor. Further, the signal generating circuit sets in the signal (i) the interval time period based on a difference between first and second voltages and (ii) the watch time period based on a difference between third and fourth voltages. The third and fourth voltages fall in a range between the first and second voltages. With the interval time period and the watch time period thus set in the signal, the periodical intermittent operation of the receiving device is realized.