Multiple heatsink cooling system for a line voltage thermostat

Patent metadata

Field	Value
Publication number	US-2016010880-A1
Application number	US-201414329357-A
Country	US
Kind code	A1
Filing date	Jul 11, 2014
Priority date	Jul 11, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

A line voltage thermostat having a multiple heatsink switch. A total switch may have a semiconductor switch mounted on each heatsink of the multiple heatsink switch. The semiconductor switches of the respective heatsinks may be connected in parallel to represent the total switch. Each of the two or more heatsinks, having a semiconductor switch for switching, and in total conveying the same power as one equivalent switch with one total heatsink, may have higher maximum operating temperatures and higher thermal resistances than twice the thermal resistance of the one total heatsink. The two or more heatsinks may be situated within a housing of the line voltage thermostat, and be easier to distribute in the housing to achieve an efficient layout of a display and control buttons for the thermostat.

First claim

1 . A thermostat for controlling an electric heater comprising:
an ambient temperature sensor; a temperature setpoint device; a comparator mechanism connected to the ambient temperature sensor and the temperature setpoint device; a power switch having a control terminal connected to the comparator mechanism; and wherein the power switch comprises:
two or more separate heatsinks;
a solid state switch situated on each heatsink; and
wherein each solid state switch has a control input connected to the control terminal of the power switch.

2 . The thermostat of claim 1 , further comprising:
a housing; and wherein the temperature setpoint device, the comparator mechanism and the power switch are situated in the housing.

3 . The thermostat of claim 1 , wherein the ambient temperature sensor is for indicating a temperature of a space containing an electric heater connected to the power switch, and for providing an output signal to the control terminal of the power switch or no output signal to the control terminal of the power switch.

4 . The thermostat of claim 1 , wherein:
the comparator mechanism compares a first temperature indication from the ambient temperature sensor and a second temperature indication from the temperature setpoint device and provides a first output signal, a second output signal or no output signal to the control terminal of the power switch; the first output signal indicates that the second temperature indication is X degrees greater than the first temperature indication; the second output signal indicates that the first temperature indication is Y degrees greater than the second temperature indication; X is a predetermined number; and Y is a predetermined number.

5 . The thermostat of claim 4 , wherein:
the first output signal turns on the power switch; and the second output signal turns off the power switch.

6 . The thermostat of claim 5 , wherein:
when the power switch is turned off, the electric heater is disconnected from electric power; and when the power switch is turned on, the electric heater is connected to electric power.

7 . The thermostat of claim 1 , wherein the solid state switch is selected from a group consisting of an SCR and a triac.

8 . The thermostat of claim 2 , wherein:
each heatsink and a corresponding solid state switch are placed in the housing at a distance from any other heatsink; and the distance is set at a maximum within the housing.

9 . A method, for controlling an electric load, comprising:
providing a thermostat comprising a power switch connectable to an electric load; determining how much power is to be delivered by an electric load; designating an amount of time the electric load is to be powered; and designing a power switch capable of turning on and off the power of an electric load, incorporating two or more solid state switches connected in parallel and attached to separate heatsinks; and wherein each of the two or more solid state switches is capable of turning on and off the power of the electric load.

10 . The method of claim 9 , further comprising:
measuring a temperature of a space having a temperature to be controlled; selecting a desired temperature to be provided to the space; and connecting the electric load to power with the power switch if the temperature of the space is less than the desired temperature; and wherein the electric load provides heat in the space to raise the temperature in the space when the electric load is connected to the power.

11 . The method of claim 10 , wherein the measuring the temperature in the space, selecting the desired temperature, and providing a signal to the power switch to connect the electric load to power are performed by a temperature sensor, a temperature setpoint device, and a comparator mechanism, respectively.

12 . The method of claim 11 , wherein the temperature setpoint device, the comparator mechanism and the power switch are contained within a housing.

13 . The method of claim 12 , wherein the housing incorporates a thermostat that comprises the temperature sensor, the temperature setpoint device, and the comparator mechanism.

14 . A heatsink cooling system for a line voltage thermostat comprising:
a switching component; and a thermostatic control; and wherein: the switching component comprises:
two or more heatsinks; and
a semiconductor switch situated on each of the two or more heatsinks; and
wherein each semiconductor switch has an input connectable to a line voltage and an output connectable to an electric load, and has a control terminal; and
the thermostatic control has an output connected to the control terminal of each semiconductor switch.

15 . The system of claim 14 , wherein the thermostatic control comprises:
a housing; a temperature sensor; a temperature setpoint mechanism; and an electronics module connected to the temperature sensor, the temperature setpoint mechanism, and the output of the thermostatic control.

16 . The system of claim 15 , wherein:
the temperature setpoint mechanism is accessible on the housing or is remote from the housing; the electronic module is situated in the housing; and the switching component is situated in the housing.

17 . The system of claim 16 , wherein the two or more heatsinks are situated in the housing at a maximum distance from one another within the housing.

18 . The system of claim 16 , wherein increasing a number of heatsinks with the switching component having a semiconductor switch situated on each heatsink of a number of heatsinks greater than one, increases a maximum operating tab temperature for each semiconductor switch and results in each of the more than one heatsinks having a thermal resistance greater than a heatsink of a switching component if the switching component has a total of one semiconductor switch situated on just one heatsink for the same amount electric load carried by the switching component having two or more semiconductor switches with each semiconductor switch having at least one heatsink.

19 . The system of claim 15 , wherein the electric load comprises an electric heater in a space having a temperature that can be measured by the temperature sensor.

20 . The system of claim 14 , wherein the semiconductor switch is selected from a group consisting of a SCR and a triac.

21 . The system of claim 18 , wherein the mass of the two or more heatsinks of the switching component having two or more semiconductor switches is less than the mass of a heatsink of the switching component having just one semiconductor switch on one heatsink for the same electrical load.

Assignees

• Honeywell Int Inc

Inventors

• Bravard Lionel
• Landry Daniel
• Tousignant Daniel
• Tremblay Evelyne
• Mcnabb-Baltar Joel

Classifications

• F24D19/1096 Primary

  for electric heating systems · CPC title

• H05K7/2039 Primary

  characterised by the heat transfer by conduction from the heat generating element to a dissipating body (arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00) · CPC title

• H05B1/02

  Automatic switching arrangements specially adapted to apparatus {; Control of heating devices} (thermally-actuated switches H01H37/00) · CPC title

• H05B1/0275

  Heating of spaces, e.g. rooms, wardrobes · CPC title

• G05D23/1902

  characterised by the use of a variable reference value · CPC title