Abstract: A controller (8) of air conditioning apparatus (18) with a cycle timer (12) for periodically actuating the apparatus (18) irrespective of temperature combined with a thermostat (10) for actuating the apparatus (18) in accordance with sensed temperature and logic circuitry (FIG. 3) for recycling the timer (12) to prevent excessive actuation of the apparatus (18) while ensuring minimum actuation in accordance with sensed conditions. Both the duration of the cycle period and the duty cycle of the timer are selectively variable over a wide range through means of timer circuitry employing dual electronic timers (12a and 12b) which are controlled to operate in a complementary manner.

Abstract: A controller (8) of air conditioning apparatus (18) with a cycle timer (12) for periodically actuating the apparatus (18) irrespective of temperature combined with a thermostat (10) for actuating the apparatus (18) in accordance with sensed temperature and logic circuitry (FIG. 3) for recycling the timer (12) to prevent excessive actuation of the apparatus (18) while ensuring minimum actuation in accordance with sensed conditions. Both the duration of the cycle period and the duty cycle of the timer are selectively variable over a wide range through means of timer circuitry employing dual electronic timers (12a and 12b) which are controlled to operate in a complementary manner.