Abstract A modulating type of thermostat controls an automatic changeover heating-cooling temperature-regulating system that sequentially adds units of cooling or units of heating as called for by the thermostat. The modulating thermostat utilizes a thermistor type of temperature sensor to control a bridge circuit and amplifier. The thermostat includes a heat anticipator in the form of a semiconductor current-carrying means such as a Zener diode that is in heat exchange relationship with the temperature sensor. The semiconductor current-carrying means acts as a constant voltage drop regardless of the amount of current flowing therethrough so that the heating effect of the semiconductor means is a linear function of the amount of current flowing therethrough. This semiconductor element provides the anticipation for both heating and cooling, the element being biased with an intermediate current at the control system dead band between heating and cooling, the current therethrough being reduced as cooling is required and increased as heating is required.
In an automatic changeover heating-cooling temperaturecontrolling system for controlling area cooling means and area heating means: sensing circuit means comprising temperature-responsive means exposed to the area to be controlled and providing an output indicative of the sensed temperature; circuit means adapted to connect said temperature-sensing means in controlling relation to the cooling means and to the heating means; linear heat output current-carrying means connected to said circuit means, said linear heat output current-carrying means being in thermal heat exchange relation with said sensing means and functioning as a heat and cool anticipator; and control means in said circuit means providing a predetermined level of current flow through said linear heat output current-carrying means during balanced conditions when neither heating nor cooling is required, and providing a decreased current therethrough when said area cooling means is operative and an increased current therethrough when said area heating means is operative.
Claim 2
Dependent Claim
148 words
In an automatic changeover heating-cooling temperaturecontrolling system for controlling area cooling means and area heating means: sensing circuit means comprising temperature-responsive means exposed to the area to be controlled and providing an output indicative of the sensed temperature; circuit means adapted to connect said temperature-sensing means in controlling relation to the cooling means and to the heating means; linear heat output current-carrying means connected to said circuit means, said linear heat output current-carrying means being in thermal heat exchange relation with said sensing means and functioning as a heat and cool anticipator; and control means in said circuit means providing a predetermined level of current flow through said linear heat output current-carrying means during balanced conditions when neither heating nor cooling is required, and providing a decreased current therethrough when said area cooling means is operative and an increased current therethrough when said area heating means is operative.
Claim 3
Dependent Claim
19 words
The system in accordance with claim 1 wherein said sensing means is a resistive network including a temperature-responsive resistor.
Claim 4
Dependent Claim
19 words
The system in accordance with claim 1 wherein said linear heat output current-carrying means is a semiconductor current-carrying means.
Claim 5
Dependent Claim
18 words
The system in accordance with claim 3 wherein said semiconductor current-carrying means comprises at least one semiconductor diode.
Claim 6
Dependent Claim
15 words
The system in accordance with claim 4 wherein said semiconductor diode is a Zener diode.
Claim 7
Dependent Claim
85 words
The system in accordance with claim 1 wherein said area cooling means is a multistage sequentially operated means and said area heating means is a multistage sequentially operated means controlled by said circuit means so that with the energization of each successive cooling stage the control means is effective to reduce the current to said linear heat output current-carrying means and with the energization of each successive heating stage the control means is effective to increase the current to said linear heat output current-carrying means.