Abstract: A thermostat has terminals to receive at least two temperature sensor signals, and changes the one of these terminals which provides the feedback signal for temperature control responsive to a detected condition. This condition may be a manual input, expiry of a time interval, reaching a time of day, or the relative magnitudes of the temperatures encoded in the sensor signals.

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 thermostat having a temporary "now" and "next" functions. The temporary "next" function allows the user to program a temporary deviation from a preprogrammed schedule used to control the temperature within a space. The combination temporary "now" and "next" function allows a user to temporarily set a current setpoint which will be held until a temporary next setpoint becomes the control setpoint, after which the thermostat returns to the preprogrammed setpoints.

Abstract: A thermostat which includes a transceiver for receiving and sending communications externally of the thermostat. A thermostat receiving external communications from another thermostat includes an external temperature responsive portion to modify the setpoint of the receiving thermostat based on the information received by the receiving thermostat.

Abstract: A setback thermostat controlling a device which holds and changes the temperature in a space includes the capability of sensing and recording the difference between the time at which recovery to a new setpoint temperature occurs and the selected time at which this temperature is specified to be reached, and if the difference is nonzero, calculates a new time at which to begin recovery the next time a change to the new temperature is specified. The calculation of the time at which recovery begins takes account of the fact that greater time is required to achieve a one degree temperature change near the new setpoint temperature than far from it because of the additional thermal load on the space as temperature nears the new set point. A non-linear function is used to calculate the time at which recovery to the new temperature is begun. The invention is included in a method for operation of the device which changes the space's temperature.

Abstract: A thermostat is disclosed which includes a Proportional-Integral-Derivative (PID) controller and a means for disabling the PID controller for selected periods. The PID controller is disabled during a temperature recovery period, which can be triggered by the occurrence of one or more of many preselected events. The PID controller is re-enabled when the thermostat setpoint less a void offset temperature is reached. To reduce error in future temperature recovery periods, the void offset temperature is adjusted after a temperature recovery by adding the amount of error to the void offset temperature to create a new void offset temperature for use in a next temperature recovery period.

Abstract: A method for randomly delaying a restart of electrical equipment following an availability of power for energizing the equipment includes the steps of measuring an environmental temperature, e.g., the room where the electrical equipment is located, converting a predetermined fractional portion of the value of the sensed temperature to a number and using the number following an availability of power for energizing the equipment after a time period having a duration restarting the equipment. An apparatus employing this method includes a restart control, a temperature sensor and an equipment start programmer responsive to the temperature sensor and connected to the restart control for producing a restart control energizing signal dependent on a predetermined fractional portion of the value of the sensed temperature.

Abstract: A temperature control system for a multiplant environmental unit such as a heat pump with auxiliary heat is disclosed. The control system utilizes a thermostat having a microprocessor and memory that allows for energy savings through setback functions. The setback functions return the temperature control from a setback temperature to a normal comfort temperature along a ramped rate that is modified from day to day. The purpose of this variable ramp is to minimize the operation of the auxliary heat and maximize shell savings (by starting as late as possible). This is basically accomplished by locking the heat pump on in certain cases.