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.

Abstract: An environmental control system has a controller (10) which causes heating apparatus (12A) or ventilation apparatus (12B) to operate through thermostatic dead zone temperature ranges, in response to excessive relative humidity. In the event the heating apparatus (12A) is actuated in response to falling temperatures, ventilation, previously called for by excess humidity, is terminated to prevent inefficiency due to concurrent heating and ventilating. After fresh air of relative lower humidity is introduced by ventilation, the fresh air is heated to further reduce the relative humidity.

Abstract: An electronic thermostat for controlling multiple temperature altering apparatus of an animal enclosure or the like. A voltage divider to produce a plurality of temperature sensor signals which are used to produce primary or override actuation signals. The set temperature signal is selectable between two set point limits which are selectively variable to calibrate different scales. A plurality of detectors respectively compare the plurality of sensor signals with a common set temperature reference signal to produce a plurality of detection signals at a plurality of preselected temperatures associated therewith. The preselected temperatures at which a first heat control detection signal is produced is different from the preselected temperature of which the first cool control detection signal is produced, so that a dead zone between cycles is created.

Abstract: An electronic thermostat for controlling multiple temperature altering apparatus of an animal enclosure or the like employs a linear sensor comprised of an elongate black body, tubular probe containing a semiconductor active element of a current source which produces a sensor current that varies linearly with changes in temperature. A voltage divider to produce a plurality of temperature sensor signals which are used to produce primary of override actuation signals. The set temperature signal is selectable between two set point limits which are selectively variable to calibrate different scales. A plurality of detectors respectively compare the plurality of sensor signals with a common set temperature reference signal to produce a plurality of detection signals at a plurality of preselected temperatures associated therewith.

Abstract: An environmental control system utilizing a single moisture and dust impervious temperature probe of a multistage thermostat to both control a fogging system in a hog house or the like and other temperature altering devices such as an adjustable ventilation system, fans, heaters and the like. In a cooling cycle of operation, when the sensed temperature rises to a first preselected level, one of the stages causes actuation of one of the temperature cooling apparatus. If the temperature continues to rise to another excessively higher preselected temperature, another stage causes actuation of the fogging system. When the sensed temperature then drops by a preselected amount, the fogging system is deactuated. The actuation and deactuation temperatures are selectively variable to minimize excessive fogging. In the heating cycle of operation, heating devices are suitably controlled in accordance with temperatures.

Abstract: An electronic thermostat with a mode selection switch for selective application of actuation signals to different output control terminals for connection with control of either cooling or heating apparatus in accordance with sensed temperature. Circuitry is provided to derive A.C. input power to a D.C. power supply from a selected one of the control terminals to eliminate the need for separate A.C. power leads. The mode selection switch also selectively applies cool and heat trigger signals to a shared actuation signal generator. Time delay circuits for delaying the time between generation of a trigger signal and resultant application of an actuation signal share a common circuit element through means of the mode selection switch.

Abstract: An automatic ventilation system for an enclosure for animals, fowl and the like, whereby plural banks of exhaust fans are controlled by respective thermostats set for operation at respective individual temperatures over an operating range of temperatures, while movable baffles or the like at air inlet apertures are adjusted under the control of a differential-pressure sensing means to regulate the rate of flow of air through the inlet apertures to maintain a desired difference between the barometric pressure within and without the enclosure irrespective of the number of banks of fans in operation at a given time; when the thermostat set at the highest temperature is actuated, the movable baffles are adjusted for maximum flow irrespective of the output of the differential-pressure sensing means, thereby establishing a second, and smaller, differential pressure; upon failure of the primary power source, a second power source is automatically utilized to adjust the inlet baffles to a position of maximum opening,