Abstract: A duct heater has a unique and symmetric arrangement of an auto limit and a pair of back up limits to permit the duct heater to be mounted in a duct in a number of different orientations. The duct heater can include a diffuser screen and have a particular size with respect to an upstream piece of equipment such as a single duct variable air volume damper box so that it can be used in these types of applications as well as stand alone applications in a duct.

Abstract: There are provided an apparatus for testing a semiconductor device and a method for testing a semiconductor device. The apparatus for testing a semiconductor device includes: a temperature detection unit detecting a temperature of a semiconductor device to generate a detected temperature; a controller comparing the detected temperature with a preset control temperature to generate a comparison result, and determining whether to cool the semiconductor device according to the comparison result; and a cooling unit cooling the semiconductor device according to a control of the controller, wherein the controller resets the control temperature, when the detected temperature is outside of a range of an operational temperature of the semiconductor device.

Abstract: A protective handle sheath including a body adapted to wrap about the existing appliance handle, a heat-activated anti-bacterial agent impregnated within the body, and first and second hook and loop strips attached to oppositely situated first and second longitudinal edges of the body respectively. The first and second hook and loop strips generate heat when engaged with each other such that the heat is transferred through the body and thereby transforms the anti-bacterial agent from an inactive state to an active state. In this manner, the anti-bacterial agent is released out from an interior of the body and thereby adapted to directly contact an outer surface of the existing appliance handle. Conversely, the anti-bacterial agent automatically returns to an inactive state when the first hook and loop strip is separated from the second hook and loop strip. Thus, the inactive anti-bacterial agent is absorbed into the interior of the body.

Abstract: A control unit (3) for controlling an electric household appliance, e.g. a refrigerator, is connected in series with a positive temperature coefficient (PTC) resistive unit (4) which, when supplied with electric current, generates sufficient heat to activate a thermally activated actuating element (6) for selectively turning on/off respective auxiliary switches (9) of the electric household appliance. The thermally activated actuating element (6) includes a temperature-deformable element (7), e.g. a bimetallic plate, the deformation of which is transmitted by kinematic links (10) to a camshaft (8), the cams (12) of which cooperate with the auxiliary switches (9) of the electric household appliance to selectively turn on/off the auxiliary switches (9).

Abstract: An apparatus 10 for controlling a temperature of an electronic device 40, comprising a temperature regulated surface 100 and an actuator 105 adapted to alternately pulse the temperature regulated surface 100 and electronic device 40 between thermally coupled and uncoupled positions, whereby a temperature of the electronic device 40 is controlled.

Abstract: An actuation device comprising:at least two thermal actuators (5A,5B) electrically supplied, each thermal actuator (5A,5B) comprising relevant thrust means (4A,6A,4B,6B) being movable to perform a predetermined stroke;at least a working means (12) moved by means of said thermal actuators (5A,5B) and connected with the thrust means (4B,6B) of one of said thermal actuators (5A,5B);where said working means (12;12A;18) is able to take at least three different steady working positions (I,II,III) in function of the presence of supply to a first (5B) or a second (5A) or both said thermal actuators (5A,5B).According to the invention, said first thermal actuator (5B) is free to move with respect to said second thermal actuator (5A) and means (6A,11) are provided for transferring the thrust produced by the second thermal actuator (5A) to the first thermal actuator (5B), and causing a change in the reciprocal positioning of one thermal actuator with respect to the other.

Abstract: A through-the-door ice and cold water dispenser for domestic refrigeration units provides a housing positioned within a recess formed in the door insulation. The dispenser provides an actuation cradle formed with a smoothly curved concave surface in combination with a switch operating system which requires low forces for operation so that the dispenser can be actuated by fragile containers, such as styrofoam cups. An insulated damper door is closed when the dispenser is not operating to prevent heat transfer into the freezer compartment where the ice is produced and stored. A heater positioned against the damper door operates to release the damper door should it become frozen in the closed position. All of the controls for the dispenser are located in the upper portion of the housing and are accessible with a minimum amount of disassembly when service or maintenance is required. A spill tray is located in the bottom of the dispenser recess to contain and retain spilled water and melted ice water.

Abstract: A microdevice in the form of an electrical switch. A microdevice for providing switching at a high repetition rate, including a cell divided into two chambers by a bistable movable membrane. A charge of gas in the cell and a source for directly heating the gas to increase the gas pressure and move the membrane, the source for heating including a pulsed source for generating transient gas pressure increases, with the cell including an arrangement for cooling the gas for reducing the gas pressure after an increase.

Abstract: A fail safe temperature control device which consists of a nonelastic container or bulb adapted to be subjected to temperature changes, a capillary tube and a pressure responsive device. The container generally is located in the area in which the heat is to be controlled, typically an oven or other heated area. The capillary tube is connected to the container at a first end and to the pressure responsive device at a second end. The nonelastic container, capillary tube and pressure responsive device form a closed system which is filled with a thermally responsive material. The pressure responsive device operates a control device, typically consisting of a normally closed contact and a normally open contact.

Abstract: A self-limiting electro-thermal actuator, capable of improved response time and continuous energization operation to produce a mechanical output uses plural heaters, e.g. a resistance heater and a positive temperature coefficient (PTC) heater, connected in series electrically. The actuator includes a boiler chamber, a thermally expansible working medium in the boiler chamber, a movable member responsive to expansion of the working medium to provide a mechanical output from the actuator, and a heater assembly for heating the working medium. The heater assembly includes the series-connected resistance electrical heater and PTC material heater. The electrical resistance of the PTC material increases with increasing temperature to limit current flow to the resistance heater. The heater arrangement produces improved response time over use of a PTC heater alone permitting actuators to be employed in applications for which known actuators are too slow.

Abstract: A large electric hotplate for restaurants and the like is heated by tubular heaters, which are placed in slots on the bottom of a cast hotplate body. An insulation with metal cover plates and a lower plate dish ensures the necessary pressing and thermal insulation. A sensor tube is placed on the outside of the downwardly projecting outer edge of the hotplate body on either side of the hotplate, said sensor tube being connected to a thermostat supplying the tubular heaters by means of several contacts.

Abstract: A fail safe device for use in conjunction with a temperature sensing bulb, capillary, and control device in an oven or other heating appliance, which fail safe device will prevent a failure of the basic control device from permitting a critical overheat condition to occur in the controlled area.

Abstract: A control system and control device for controlling a heating unit and method of making the control device are provided, the control device having a rod and tube temperature sensing unit for providing linear motion of a part thereof along a substantially straight linear path in relation to the temperature being sensed by the temperature sensing unit and having a potentiometer unit provided with an electrical output producing unit operatively interconnected to the part of the temperature sensing unit so as to produce a variable electrical signal in relation to the temperature being sensed by the temperature sensing unit, the electrical output unit being movable along an arcuate linear path by the part of the temperature sensing unit. The potentiometer unit has a member provided with an arcuate surface, the electrical output unit being disposed in sliding engagement with the arcuate surface whereby the arcuate surface defines the arcuate path of movement of the electrical output unit.

Abstract: A temperature controlled switching device in which a first fluid filled temperature sensor responding to the temperature of heating or cooling means moves a first lever. A second sensor sensing the room temperature moves a second lever. The two levers being interconnected to move a snap action switch for control of the heating or cooling means.

Abstract: This invention relates generally to apparatus wherein a change in temperature is transmitted from a sensing bulb through a capillary to a control device. More particularly this invention is related to a novel, fail safe device for use in conjunction with a temperature sensing bulb, capillary, and control device in an oven or other heating appliance.

Abstract: This invention relates generally to thermal control apparatus wherein a change in temperature is transmitted from a sensing bulb through a capillary to a control device. More particularly this invention is related to a novel, fail-safe control device for use in conjunction with a temperature sensing bulb, capillary, and control device in an oven or other heating facility whereby a loss of pressure within the bulb, capillary, control device system will cause the heating device to be shut off and thus will prevent the oven or other heating facility from being overheated.

Abstract: An elongated temperature-sensing probe is positioned in a deep fat cooking vessel and is positioned so that a portion of the probe extends adjacent the electric heater submerged in the deep fat adjacent the bottom of the vessel, and a portion extends upward in the fat into the cooking zone in the vessel. The temperature-sensing probe is connected to control the power to the heater. The heater is thermally connected to the probe so that the probe receives direct conduction heat from the heater as well as senses the heat adjacent the heater and in the cooking zone.

Abstract: Apart from its conventional power main heating system, which is manually controlled by a power control device, an electric hotplate has an additional heating system, which is connected in parallel to the main heating system and in series with a temperature switch and an additional contact, which is operated by the adjusting shaft of the power control device in an upper or medium power range of the hotplate. The temperature switch is a relatively inertly operating thermal cutout with a high switching hysteresis, which in this case serves as a timing element which is not normally switched on again once it has been switched off. Continuously adjustable timing power control units and seven-cycle switches are provided as the power control device.

Abstract: A two-circuit automatic hotplate has a switch, which can be controlled both by a bimetallic strip of a power control device and by an expansion member of a hydraulic temperature sensor. The control heating system of the bimetallic strip is in series with a cooking heating system of the hotplate.The electric power levels of the cooking heating systems are preferably selected in such a way that, wherever possible, a current of the same level flows through the control heating system for the bimetallic strip, so that the same bimetallic strip can always be used.

Abstract: The invention relates to control apparatus for heat actuated devices of the type having a heating resistor and a spring biased motor member movable in response to heat generated by the resistor. A source of rectified AC voltage for the heating resistor is regulated by a controlled rectifier in series with the resistor. There is a comparator circuit for comparing a desired setting with the actual position of the motor member and generating a continuously variable control signal of a value corresponding to the departure value. An ignition circuit for pulsing the controlled rectifier has inputs including the control signal, a half wave AC voltage and a time dependent decreasing signal. The ignition circuit has an input threshold below which pulses are generated and above which pulses are not generated.

Abstract: Apparatus for precisely regulating the paraffin temperature in an electrically heated tissue processor comprises a sensor which is detachably fastened to the tissue processor by a clamp so as to be partially immersed in the paraffin. A controller, coupled to the sensor, and coupled in series with the tissue processor heating element by a plug tap across a source of alternating current voltage, is responsive to the conduction state of the sensor and controls the delivery of power to the tissue processor heating element in accordance with the paraffin temperature as sensed by the sensor.

Abstract: A linear pull actuator converts working fluid such as halogenated hydrocarbons into vapor by electrical heating element housed inside a shell, generating a vapor pressure against a rolling membrane secured inside actuator so as to respond to the vapor pressure linearly delivering an end force to an integral first piston and tube assembly which is adaptable to axially move inside the housing proper against spring biasing means along with an externally mounted second piston of a piston and rod assembly secured thereto by a spring so as to have rod end passing centrally through the tube protrude a distance out of the shell end for a position change from a first rod end protruded when electrical heater is not energized electrically to a second rod end retracted position with work when pulled away by the pistons due to the vapor pressure of the working fluid when the electrical heater is energized electrically, de-energization of the electrical heating element electrically returns the rod end to the first protrude

Abstract: A positive temperature coefficient heater for enhancing the response time of thermal actuators is disclosed. The PTC heater is formed of a generally low resistance material that has an anomaly temperature above which the resistance of the heater increases dramatically. The anomaly temperature is chosen to substantially match the phase change temperature of a thermally expansive medium useful to power the actuator. The heater is self-regulating and provides a maximum surface area for heating the medium rapidly with a minimum of thermal mass and energy use. Preferably, the heater is formed of doped BaTiO.sub.3 in the general shape of an elongated annular cylinder.

Abstract: A partitioning sleeve is positioned in the main body of a thermal actuator to form a separate internal liquid reservoir from which fluid may be supplied to the actuator heater. The heater is part of a heater sub-assembly that is sealed in an opening formed in the main body of the actuator so that the coil-type electric resistance heater is accurately positioned for submersion in liquid in the variable volume chamber formed in the main body of the actuator. Moreover, the recycling or cool down time for the thermal actuator is reduced by thermal transfer between an appreciable contacting surface area of an extensible diaphragm that partly forms the actuator chamber and a guide cap that also supports and guides the diaphragm during its extension to enlarge the variable volume chamber.

Abstract: A thermostatically controlled safety heater for upright immersion in an aquarium includes a housing with an axially extending, heat-transmitting tube forming a chamber in which an electric heating element is disposed in radially spaced relation from the tube. The radial space between the tube and element, over substantially the axial length of the element, is filled with a heat conducting, thermally expansible liquid. An actuator device including a linearly movable plunger reactive to thermal expansion of the liquid is provided for opening and closing a switch in circuit with the heating element for maintaining the heater at a desired temperature. A hunting tendency of the switch contacts is overcome by providing a damping medium in the form of an air space having a volume less than about ten per cent of the volume of liquid between the plunger and the liquid. An expansible sealing diaphragm supports the plunger and isolates the liquid to the portion of the tube in which the heating element is disposed.