Multiple heatsink cooling system for a line voltage thermostat
View Patent ↗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.
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 in parallel to the other solid state switches to the control terminal of the power switch to form the power switch; and
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.
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 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 3 , 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 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.
8. 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 to form the power switch and attached to separate heatsinks;
measuring a first temperature of a space having a temperature to be controlled; and
comparing a first temperature and a second temperature indication from the thermostat;
providing a first output signal indicating that the second temperature indication is X degrees greater than the first temperature, a second output signal that indicated that the first temperature is Y degrees greater than the second temperature indication, or no output signal to the power switch; and
wherein each of the two or more solid state switches is capable of turning on and off the power of the electric load.
9. The method of claim 8 , further comprising:
connecting the electric load to power with the power switch if the temperature of the space is less than the desired temperature in response to the first output signal; 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.
10. The method of claim 9 , 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.
11. The method of claim 10 , wherein the temperature setpoint device, the comparator mechanism and the power switch are contained within a housing.
12. The method of claim 11 , wherein the housing incorporates a thermostat that comprises the temperature sensor, the temperature setpoint device, and the comparator mechanism.
13. A heatsink cooling system for a line voltage thermostat comprising:
a switching component; and
a thermostatic control;
a comparator mechanism; 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;
the comparator mechanism compares a first temperature indication from an ambient temperature sensor and a second temperature indication from the thermostatic control and provides a first output signal, a second output signal or no output signal to the control terminal of the switching component;
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.
14. The system of claim 13 , wherein the thermostatic control comprises:
a housing;
a temperature setpoint mechanism; and
an electronics module connected to the ambient 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 electronic module is situated in the housing; and
the switching component is situated in the housing.
16. The system of claim 15 , 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 16 , 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.