Abstract: An interface circuit is designed to connect a first logic circuit such as a microcontroller with a second similar microcontroller using three wires and allowing for simultaneous transfer of data from each of the microcontrollers to the other. A transmitter element in each interface circuit has a bias resistor which cooperates with a pull-up resistor in the other interface circuit to provide an indication for one of the logic circuits when the other of the logic circuits and its associated interface circuit loses power or when one of the three connecting wires is disconnected.

Abstract: A controller for a climate control system has a humidity (wet-bulb or dew point) temperature sensor as well as a dry-bulb temperature sensor within the enclosure. The humidity temperature value is used in connection with the dry-bulb temperature to generate a single error signal which is a function of both the dry-bulb and the humidity temperature values. This permits control of both enclosure temperature and enclosure humidity without abnormal cycling of the climate control system. Instead of using a sensor which directly measures the humidity temperature, the humidity temperature can be synthesized from the relative humidity and dry-bulb temperature within the enclosure.

Abstract: A thermostat for providing control signals to a variable capacity HVAC system. The thermostat being a setback thermostat with a ramping set point for the recovery period. The thermostat monitoring the load signal required during recovery and increasing or decreasing the ramp slope accordingly.

Abstract: A thermostat which provides a pulse width modulated signal to a gas engine heat pump controller. The thermostat varies the width of the pulse width modulated signal to indicate the load required to heat or cool the room. The thermostat provides an initial idle time for the gas engine heat pump. The thermostat further steps the gas engine heat pump down from high speed operation and idles the engine prior to shutting the engine off.

Abstract: A printed wiring board connector which mechanically supports the board. A connector base has legs which extend away from ends of the base and terminate in stakes which penetrate the board for attachment and electrical connection. Walls extend from the base, arch over the base, and terminate above the base. A conductive protrusion extending from a mounted electrical device is secured between the free ends of the walls and the base providing both support of the printed wiring board and electrical connection.

Abstract: A switch operator has a low friction ratchet wheel driven by a low power time programmed clock to operate the switch in one position or another depending upon the position of the ratchet wheel to operate the ratchet wheel independent of the time programmed clock. A pawl resiliently held and biased away from the ratchet wheel engages the ratchet wheel when moving in a forward direction to move it a predetermined amount. A cam member mounted adjacent the ratch wheel is engaged by the pawl to bias the pawl against a projection on the ratchet wheel when the pawl is moved forward and to bias the pawl away from the ratchet wheel upon its return movement.

Abstract: A vibration isolating motor mount has a U-shaped mount having the end of the legs of the "U" arranged at right angles thereto to form mounting ears. One leg end ear is arranged to be connected to a motor support plate which is perpendicular to the plane of the legs of the U-shaped mount. The plate is, in turn, attached to a first end of the motor with the plane of the plate being perpendicular to the axis of rotation of the motor. The end ear of the other leg is arranged to be connected to a motor support frame having the plane of the frame also perpendicular to the axis of rotation of the motor. The other end ear may include a vibration absorbing bushing isolating the respective mounting ear while surrounding a mounting pin attached to the support frame. The plane of the legs of the U-shaped mount is arranged to be co-planar with the axis of rotation of the motor. A plurality of the motor mount may be equally spaced on the periphery of the motor support place to provide added support for the motor.