초록 ▼

A two-stage circuit for controlling all operational functions of a reversible air cycle heat pump unit, including room thermostat functions and defrosting functions. All user controllable functions are controlled via a remotely locatable thermostat-like control unit mounted on an inside wall of the

A two-stage circuit for controlling all operational functions of a reversible air cycle heat pump unit, including room thermostat functions and defrosting functions. All user controllable functions are controlled via a remotely locatable thermostat-like control unit mounted on an inside wall of the room separate from the heat pump unit, and connected to the heat pump unit with only five conductors. A number of desirable functions and features are provided. For example, for optimum energy usage the control provides two stages in both heating and cooling modes of operation, with almost constant temperature differential between the two stages regardless of temperature setting, and almost constant hysteresis for each stage. To facilitate compliance with Government-imposed regulations where applicable, heating and cooling limits are independently adjustable without any modification whatsoever for use in those public buildings where heating and cooling must be limited.

대표청구항 ▼

A two stage control circuit for a reversible air conditioning unit of the type having a heating mode and a cooling mode of operation and including operational elements for providing first and second stages of heating and cooling, said control circuit comprising: a mode switch for making predetermine

A two stage control circuit for a reversible air conditioning unit of the type having a heating mode and a cooling mode of operation and including operational elements for providing first and second stages of heating and cooling, said control circuit comprising: a mode switch for making predetermined electrical connections depending upon whether heating mode or cooling mode operation is selected; a first stage controlled switching device connected, when activated, to energize the first stage operational elements; a second stage controlled switching device connected, when activated, to energize the second state operational elements; thermostatic control circuitry for comparing sensed indoor temperature with a temperature setting and for activating said first and second stage controlled switching devices depending upon the difference between sensed indoor temperature and the temperature setting, said thermostatic control circuitry operable when the heating mode is selected to activate said first stage switching device if sensed indoor temperature is below the temperature setting and to additionally activate said second stage switching device if sensed indoor temperature is below the temperature setting by a predetermined differential amount, and operable when the cooling mode is selected to activate said first stage switching device if sensed indoor temperature exceeds the temperature setting and to additionally activate said second stage switching device if sensed indoor temperature exceeds the temperature setting by a predetermined differential amount; a user control unit locatable remotely from a main portion of said control circuit, with power supplied to said remotely locatable user control unit from said control circuit main portion via a pair of supply conductors, one of said pair of supply conductors being subdivided into a heating mode select conductor and a cooling mode select conductor alternately selected for continuity by said mode switch; said remotely locatable user control unit having a temperature setting potentiometer connected in adjustable voltage divider configuration across said pair of supply conductors to provide a voltage representative of the desired degree of heating or cooling; said remotely locatable user control unit further having an indoor temperature sensor connected in a circuit to provide a voltage representative of the actual degree of heating or cooling, said indoor temperature sensor circuit responsive to said heating and cooling mode select conductors to selectively cause the voltage representative of the actual degree of heating or cooling to vary either directly or inversely with sensed temperature; a heat limiting trimmer resistor and a cool limiting trimmer resistor respectively selected in response to said heating and cooling mode select conductors and arranged in combination with said potentiometer to controllably limit user selection of the voltage representative of the desired degree of heating or cooling; and comparator circuitry responsive to the voltage representative of desired degree of heating or cooling and to the voltage representative of the actual degree of heating or cooling to activate said first and second stage controlled switching devices depending upon the amount by which the voltage representative of the actual degree of heating or cooling falls short of the voltage representative of desired degree of heating or cooling.