Multiple heatsink cooling system for a line voltage thermostat

Patent metadata

Field	Value
Publication number	US-10088174-B2
Application number	US-201715624673-A
Country	US
Kind code	B2
Filing date	Jun 15, 2017
Priority date	Jul 11, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

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

What is claimed is:

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 having an input connected to the ambient temperature sensor and the temperature setpoint device and configured to receive temperature indications from the ambient temperature sensor and the temperature setpoint device and determine to connect and disconnect the electric heater from a power source based on the received temperature indications;
a power switch positioned within the housing, the power switch having a control terminal connected to an output of the comparator mechanism allowing the comparator mechanism to open and close the power switch in response to the comparator mechanism determining to connect and disconnect the electric heater from the power source; and
wherein the power switch comprises:
two or more separate heatsinks;
a solid state switch situated on each heatsink; and
wherein the solid state switches are connected in parallel to one another and connected to the control terminal allowing the comparator mechanism to open and close each solid state switch.

2. The thermostat of claim 1 , wherein the ambient temperature sensor is for indicating a temperature of a space containing the 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 received temperature indications include a first temperature indication from the ambient temperature sensor and a second temperature indication from the temperature setpoint device and the comparator mechanism compares the first temperature indication from the ambient temperature sensor and the second temperature indication from the temperature setpoint device and provides a first output signal, a second output signal or the comparator mechanism does not provide an 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;
no output signal is provided when the second temperature indication is not X degrees greater than the first temperature indication and the first temperature indication is not 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;
the second output signal turns off the power switch; and
no output signal leaves the power switch at its current state.

5. The thermostat of claim 4 , wherein:
when the power switch is turned off, the electric heater is disconnected from the power source; and
when the power switch is turned on, the electric heater is connected to the power source.

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 having an input connected to the ambient temperature sensor and the temperature setpoint device and configured to receive temperature indications from the ambient temperature sensor and the temperature setpoint device and determine to connect and disconnect the electric heater from a power source based on the received temperature indications;
a power switch positioned within the housing, the power switch having a control terminal connected to an output of the comparator mechanism allowing the comparator mechanism to open and close the power switch in response to the comparator mechanism determining to connect and disconnect the electric heater from the power source; 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 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 the solid state switches are connected in parallel to one another and connected to the control terminal allowing the comparator mechanism to open and close each solid state switch.

9. The thermostat of claim 8 , wherein the ambient temperature sensor is for indicating a temperature of a space containing the 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 received temperature indications include a first temperature indication from the ambient temperature sensor and a second temperature indication from the temperature setpoint device and the comparator mechanism compares the first temperature indication from the ambient temperature sensor and the second temperature indication from the temperature setpoint device and provides a first output signal, a second output signal or the comparator mechanism does not provide an 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;
no output signal is provided when the second temperature indication is not X degrees greater than the first temperature indication and the first temperature indication is not 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;
the second output signal turns off the power switch; and
no output signal leaves the power switch at its current state.

12. The thermostat of claim 11 wherein:
when the power switch is turned off, the electric heater is disconnected from the power source; and
when the power switch is turned on, the electric heater is connected to the power source.

13. A heatsink cooling system for a line voltage thermostat comprising:
a switching component having a control terminal and comprising two or more heat-sinks connected in parallel, each heat-sink including a semiconductor switch situated thereon, wherein the parallel arrangement causes a decrease in power supplied to each semiconductor switch allowing the switching component to operate at an increased temperature; and
a thermostatic control having an output; and
a comparator mechanism having an input connected to the output of the thermostatic control and having an output connected to the control terminal of the switching, the comparator mechanism configured to compa

Assignees

• Honeywell Int Inc

Inventors

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

Classifications

• F28F13/00

  Arrangements for modifying heat-transfer, e.g. increasing, decreasing (F28F1/00 - F28F11/00 take precedence) · CPC title

• H05B1/02

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

• G05D23/20

  with sensing elements having variation of electric or magnetic properties with change of temperature (G05D23/13 takes precedence) · 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

• G05D23/1902

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