MULTIPLE HEATSINK COOLING SYSTEM FOR A LINE VOLTAGE THERMOSTAT

• US 20170307231A1
• Filed: 06/15/2017
• Published: 10/26/2017
• Est. Priority Date: 07/11/2014
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Bravard, Lionel, Landry, Daniel, Tousignant, Daniel, Tremblay, Evelyne, McNabb-Baltar, Joel
• Granted Patent: US 10,088,174 B2
• Time in Patent Office: Days
• CPC Class Codes: F28F 13/00 Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: G05D 23/20 with sensing elements having variation of electric or magnetic properties with change of temperature G05D23/13 takes precedence
• CPC Class Codes: H05B 1/02 Automatic switching arrangements specially adapted to apparatus ; Control of heating devices thermally-actuated switches H01H37/00
• CPC Class Codes: H05B 1/0202 Switches
• CPC Class Codes: H05B 1/0275 Heating of spaces, e.g. rooms, wardrobes
• CPC Class Codes: H05K 7/2039 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

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.

Claims

1. A thermostat for controlling an electric heater comprising:

a housing;

a display positioned in the housing;

a temperature setpoint device disposed within the housing;

an ambient temperature sensor;

a comparator mechanism disposed within the housing, the comparator mechanism connected to the ambient temperature sensor and the temperature setpoint device;

a power switch positioned within the housing, the 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 in parallel to the control terminal of the power switch.

2. 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.

3. 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.

4. The thermostat of claim 3, wherein:

the first output signal turns on the power switch; and

the second output signal turns off the power switch.

5. The thermostat of claim 4, 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.

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

7. The thermostat of claim 1, 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.

8. A thermostat for controlling an electric heater comprising:

a housing;

a display positioned in the housing;

a temperature setpoint device disposed within the housing;

an ambient temperature sensor;

a comparator mechanism disposed within the housing, the comparator mechanism connected to the ambient temperature sensor and the temperature setpoint device;

a power switch positioned within the housing, the power switch having a control terminal connected to the comparator mechanism; and

wherein the power switch comprises;

a first heatsink having a first solid state switch situated thereon, the first heatsink positioned at a first location within the housing;

a second first heatsink having a second solid state switch situated thereon, the second heatsink positioned at a second location within the housing, the second location positioned a maximum distance from the first location; and

wherein each solid state switch has a control input connected in parallel to the control terminal of the power switch.

9. The thermostat of claim 8, 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.

10. The thermostat of claim 8, 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.

11. The thermostat of claim 10, wherein:

the first output signal turns on the power switch; and

the second output signal turns off the power switch.

12. The thermostat of claim 11 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.

13. A heatsink cooling system for a line voltage thermostat comprising:

a switching component comprising two or more heat sinks connected in parallel, each heat sink including a semiconductor switch situated thereon; and

a thermostatic control; and

a comparator mechanism, the comparator mechanism configured to compare a first temperature indication from an ambient temperature sensor and a second temperature indication from the thermostatic control and to provide a first output signal, a second output signal or no output signal to a control terminal of a power switch;

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.

14. The system of claim 13, wherein the thermostatic control comprises:

a housing;

a display;

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.

15. The system of claim 14, wherein:

the temperature setpoint mechanism is accessible on the housing or is remote from the housing;

the electronics module is situated in the housing; and

the switching component is situated in the housing.

16. The system of claim 14, wherein the two or more heatsinks are situated in the housing at a maximum distance from one another within the housing.

17. The system of claim 14, wherein the electric load comprises an electric heater in a space having a temperature that can be measured by the temperature sensor.

18. The system of claim 13, wherein the semiconductor switch is selected from a group consisting of a SCR and a triac.

19. The system of claim 13, 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.

20. The system of claim 13, 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 two or more 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.