With Protective Means For Heater Patents (Class 219/481)
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Patent number: 6263782Abstract: A device for sensing the presence of cooking utensils on a cooking hob comprising at least one heat source. The device includes an electrically conductive coil turn fed by the signal generated by an oscillator. The oscillator is preferably a voltage-controlled oscillator generating square wave signals. The coil turn operates, when utensil sensing occurs, to modify the cut-off frequency of a low pass filter (L/R) fed by said oscillator (VCO).Type: GrantFiled: December 11, 2000Date of Patent: July 24, 2001Assignee: Whirlpool CorporationInventors: Franco Brindani, Luca Frasnetti
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Publication number: 20010008236Abstract: A heating appliance such as an electric heating blanket having a control circuit which controls the application of power to the heating element of the blanket based on the condition of the heating element. The circuit senses the voltage at the end of the heating element in order to determine if the heating element has a short or an open circuit condition therein. Under normal conditions, the sensed voltage will be above a predetermined threshold value. If the sensed voltage falls below the threshold value, the control circuit shuts off power to the heating element. The control circuit will keep power off until the fault condition has been corrected and power has been removed and reapplied to the control circuit.Type: ApplicationFiled: January 13, 2000Publication date: July 19, 2001Inventor: John Allard
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Patent number: 6262401Abstract: A self-cleaning water heater element is provided. The water heater element is plated with a layer of gold such that the gold surface has a low surface roughness. The smooth gold surface inhibits scale formation on the water heater element. The gold-plated smooth-surfaced water heater element may be manufactured by coating a standard water heater element with an adhesion layer, electroplating a layer of bright nickel on the adhesion layer, and electroplating a gold layer on top of the bright nickel layer.Type: GrantFiled: December 22, 1999Date of Patent: July 17, 2001Assignee: AOS Holding CompanyInventors: Ray O. Knoeppel, Dennis R. Hughes
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Patent number: 6252208Abstract: A method and a circuit for controlling the heating current of a seat heater as a function of temperature is described. The circuit has a temperature sensing element that is integrated into an assigned logic circuit. The method optimizes a seat heating control arrangement by using variable heating phase durations.Type: GrantFiled: July 14, 2000Date of Patent: June 26, 2001Assignee: Robert Bosch GmbHInventor: Rainer Topp
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Patent number: 6232582Abstract: A cooking oven and method which compensates for variations in line voltage so as to achieve uniform cooking results that are independent of line voltage. The method includes providing an oven having a radiant energy source mounted therein, initiating a selected cooking cycle in the oven, measuring the line voltage across the radiant energy source and determining the increase or decrease in the line voltage above or below a predetermined nominal value. An adjusted energization time is determined relative to the predetermined energization time, using the determined increase or decrease in line voltage. The cooking cycle is completed using the adjusted energization time.Type: GrantFiled: April 13, 1999Date of Patent: May 15, 2001Assignee: Quadlux, Inc.Inventors: William Minnear, John O'Neill, Chris Tatarian, Don Pettibone
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Patent number: 6222162Abstract: An electric blanket includes a heating element extending through the blanket so that, upon receiving electric current from a power source, the element heats the blanket. A regulator circuit is connected to the element. It is configured to measure the resistance of the element and to control delivery of the electric current from the power source to the element responsively to the resistance so that the element heats to a desired temperature.Type: GrantFiled: September 30, 1999Date of Patent: April 24, 2001Inventor: Barry P. Keane
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Patent number: 6222164Abstract: A temperature control system for a thermal reactor is disclosed that addresses many of the problems in the art. In accordance with one aspect of the disclosed control system, a plurality of temperature controllers are employed. Each temperature controller employs one or more dynamic models that are optimized for a given temperature range. The temperature range over which a particular controller is optimized is preferably generally exclusive of the temperature ranges over which other controllers of the plurality of temperature controllers are optimized. In accordance with another aspect of the control system the control system employs enhanced ramp trajectory logic. In accordance with another aspect of the control system, the control system employs a virtual temperature sensor in the event of a hardware failure of the corresponding non-virtual temperature sensor.Type: GrantFiled: August 31, 1999Date of Patent: April 24, 2001Assignee: Semitool, Inc.Inventors: Kevin Stoddard, Paul R. McHugh, Konstantinos Tsakalis
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Patent number: 6211495Abstract: A temperature control system for a thermal reactor is disclosed that addresses many of the problems in the art. In accordance with one aspect of the disclosed control system, a plurality of temperature controllers are employed. Each temperature controller employs one or more dynamic models that are optimized for a given temperature range. The temperature range over which a particular controller is optimized is preferably generally exclusive of the temperature ranges over which other controllers of the plurality of temperature controllers are optimized. In accordance with another aspect of the control system, the control system employs enhanced ramp trajectory logic. In accordance with another aspect of the control system, the control system employs a virtual temperature sensor in the event of a hardware failure of the corresponding non-virtual temperature sensor.Type: GrantFiled: August 31, 1999Date of Patent: April 3, 2001Assignee: Semitool, Inc.Inventors: Kevin Stoddard, Paul R. McHugh, Konstantinos Tsakalis
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Patent number: 6191396Abstract: A heater abnormality detecting circuit includes a heater winding. A fly back pulse extracted by the heater winding is supplied to a heater through a heater resistor, and voltage-divided and supplied to a micro-computer. The micro-computer determines a normality or abnormality on the heater by determining whether or not it is inputted with the voltage-divided fly back pulse in a predetermined time period.Type: GrantFiled: November 17, 1998Date of Patent: February 20, 2001Assignee: Funai Electric Co. Ltd.Inventor: Kazuhiko Yamamoto
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Patent number: 6188049Abstract: An initial power feed quantity to be provided at the start to an electric heater equipped to an air-fuel ratio sensor is set corresponding to the temperature of a sensor element, and at the same time, the increase control time for increasingly changing the power feed quantity from said initial power feed quantity to the maximum power feed quantity is set corresponding to the temperature of the sensor element, and according to said initial power feed quantity and said increase control time, the power feed quantity to said electric heater is increased gradually from the start.Type: GrantFiled: January 19, 1999Date of Patent: February 13, 2001Assignee: Unisia Jecs CorporationInventor: Masanobu Osaki
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Patent number: 6140620Abstract: A device for disconnecting an electric appliance or a component thereof from a source of electricity including a circuit connecting the appliance or component thereof to a power source through a relay or other component to open the circuit; and a timer circuit connected to the relay. The timer circuit includes a processor for setting the timer circuit, and a manually operated switch in communication with the processor. The timer circuit is activated for a predetermined time increment by closing the switch, and the relay is closed while the timer circuit is activated. When the switch is closed again while the timer circuit is activated, an additional time increment is added to the activation period.Type: GrantFiled: March 30, 1999Date of Patent: October 31, 2000Inventors: James E. Aldridge, Carol F. Stewart
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Patent number: 6137091Abstract: Due to a bimetallic contact point, a fine control is out of sight. Further, dispersion of bimetal characteristics and poor durability of a contact point cause problems, particularly in maintenance work. In order to overcome these problems, a controller for extending a service life of the contact point can provide a fine control, so that a maintenance-free electric cooker can be provided. The ON/OFF of the contact point of relay is controlled to operate at zero potential of commercial power, and a short-pulse-signal-switch that allows the relays to remove deposition by itself even if the contact point encounters deposition, are prepared and applied to plural heaters for controlling thereof.Type: GrantFiled: July 26, 1999Date of Patent: October 24, 2000Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Mitsuhiko Kikuoka, Satoru Shibata
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Patent number: 6136280Abstract: An autoclave type sterilization device which includes an autoclave sterilization chamber with an electrical heating arrangement mounted thereon. This electrical heating arrangement employs one or more positive temperature coefficient (PTC) thermistors as heating elements. These heating elements are in direct thermal and electrical contact on opposing sides, which are coated with a conductive metal such as aluminum, with electrodes to supply electrical current. These electrodes are, in turn, in direct thermal contact on their outward-facing sides with respect to the heating elements with plates which are formed of a thermally conductive and electrically insulating ceramic material such as AL.sub.2 O.sub.3, and the plates are in direct thermal contact on their outward-facing sides with respect to the heating elements with heat radiation units which include heat transfer portions which are fabricated to engage and are in direct thermal contact with a portion of the wall of the autoclave chamber.Type: GrantFiled: April 6, 1998Date of Patent: October 24, 2000Assignee: Body Heat Ltd.Inventors: Gad Golan, Yuly Galperin
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Patent number: 6130412Abstract: A method is disclosed for detecting a condition indicative of fire or elevated potential for fire, broadcasting a signal in response to its detection and for operating various controlling devices in response to the broadcast signal in order to enable or disable valves or appliances connected to a power supply through the controllers. Also disclosed is a system having a sensor, a transmitter responsive to the sensor, a receiver for receiving signals from the transmitter and controllers responsive to a signal from the receiver for controlling devices in accordance with the method of the invention. Each of the controllers is shifted from its normal position to a second position upon the receipt of a signal from any one of the sensors, and more than one controller device may be controlled by a given receiver.Type: GrantFiled: January 14, 1999Date of Patent: October 10, 2000Assignee: SSM TechnologiesInventor: Charles Timothy Sizemore
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Patent number: 6118934Abstract: A safety protection structure for aquarium heater, including an anti-corrosion tube body in which an insulative receptacle, an electric heater, a thermal control switch, an anti-oxidation heat conductive layer, a grounding mechanism and multiple water-sealing members are disposed. The safety protection structure serves to protect the heater from leakage of electricity, blowing up due to abruptly increasing temperature after separated from the water and burning of environmental articles by over-heated surface of the heater after separated from the water.Type: GrantFiled: November 12, 1998Date of Patent: September 12, 2000Inventor: Chuan-Tseng Tseng
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Patent number: 6118104Abstract: The present invention provides a method of determining the boil states of a liquid as measured by an acoustic sensor which measures the acoustic signal generated by the liquid as it is heated. The acoustic signal is smoothed and a first derivative of the acoustic signal is calculated. Also the frequency of the acoustic signal is measured. Derivative inflection points, zero slope points, and acoustic signal frequencies are utilized to determine the pre-simmer, simmer, pre-boil, boil, boil dry, and boil over states of the liquid.Type: GrantFiled: March 19, 1999Date of Patent: September 12, 2000Assignee: General Electric CompanyInventors: Ertugrul Berkcan, Pierino Gianni Bonanni, Vivek Venugopal Badami, Emilie Thorbjorg Saulnier
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Patent number: 6118105Abstract: A monitoring and control system for monitoring the boil states of the contents of a cooking utensil located on a cooking surface of a cooktop, indicating the state to a user, and controlling the energy applied to the cooking surface, which may be a glass ceramic. The system includes at least one controllable heat source located below the lower surface of the cooktop so as to heat the cooktop and cooking utensil, at least one sensor located in proximity to the cooktop, which senses the temperature of at least one of the cooktop and the cooking utensil, at least one power indicative signal, and a signal processing device receiving a temperature signal from the sensor, and the power indicative signal. The signal issued by the sensor is representative of the temperature of either the cooktop, or the cooking utensil.Type: GrantFiled: July 19, 1999Date of Patent: September 12, 2000Assignee: General Electric CompanyInventors: Ertugrul Berkcan, Emilie Thorbjorg Saulnier, Paul Randall Wilson, Vivek Venugopal Badami
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Patent number: 6107611Abstract: A reflector assembly in a satellite system includes a reflector having a reflecting surface. At least one sensor is configured for sensing a temperature of the reflecting surface or moisture associated with the reflecting surface. Each sensor is configured to provide a signal indicative of the sensing. A heater is configured for heating the reflecting surface. The heater includes a heater wire, a layer of insulation substantially surrounding the heater wire, and a conductive shield substantially surrounding the layer of insulation. A ground fault circuit interrupter is coupled with the shield of the heater. The ground fault circuit interrupter is configured for detecting a ground fault condition between the heater wire and the conductive shield and providing a signal indicative thereof. An automatic controller is connected to the at least one sensor. The controller includes heater control circuitry receiving each of the sensor signal and the ground fault circuit interrupter signal.Type: GrantFiled: May 22, 1998Date of Patent: August 22, 2000Assignee: MSX, Inc.Inventor: Thaddeus M. Jones
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Patent number: 6100510Abstract: A control device includes both a heating element and a temperature sensor. The control device has the form of a Wheatstone bridge which applies sensing current to the heating element. When the bridge is unbalanced, the control device may apply heating current to the heating element. In one embodiment, the sensing current is switched, so that it flows only for a relatively small part of the electrical cycle. The circuit also includes a provision for reduction or elimination of electrical spikes. The circuit further includes a calibration arrangement, which enables the user to adjust the bridge without passing heating current through the heating element. Another feature of the invention enables the set point of the bridge to be remotely controlled, by adjusting a level of analog current applied to the bridge. The circuit also includes an arrangement for compensating for temperature-induced changes in its components.Type: GrantFiled: October 21, 1998Date of Patent: August 8, 2000Assignee: Bruce E. MetzInventors: Stephen T. Chen, Bruce E. Metz
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Patent number: 6084218Abstract: A heater assembly for use with spas, hot tubs and the like, includes a control circuit which controls the application of electrical power to the heater. A control circuit controls application of power to the heater in response to a thermostat setting, the flow of water in the spa system and in response to a high limit temperature. When the high limit temperature is exceeded, electrical power to the heater is removed. Electrical power to the heater cannot be restored until power to the entire system is turned off and then back on. The control circuit is mounted on the heater and includes spring-loaded standoffs which maintain the temperature sensors in good thermal contact with the body of the heater.Type: GrantFiled: May 25, 1999Date of Patent: July 4, 2000Assignee: ITT Manufacturing Enterprises, Inc.Inventor: William B. McDonough
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Patent number: 6046441Abstract: The present invention relates to a device for automatically disabling power to an electrical appliance as a fire erupts. The device includes a plurality of combustion product gas sensors disposed within or proximal to an electrical appliance each in communication with an audible alarm and an electrical contactor via a relay. The electrical contactor is received within an auxiliary plug which is coupled with the appliance plug such that, when the sensors detect a predetermined concentration of carbon dioxide or carbon monoxide, the contactor opens to disable power to the appliance and an audible alarm is simultaneously emitted.Type: GrantFiled: May 5, 1998Date of Patent: April 4, 2000Inventor: Thomas Robert Daffron
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Patent number: 6020576Abstract: An apparatus and method for temperature sensing and for detecting cracks or breakage of a windshield. A resistance element is connected to the windshield and a resistance monitoring circuit is connected to the resistance element for monitoring an electrical property of the resistance element. A physical integrity monitoring device can be connected to the resistance monitoring circuit for determining the physical integrity of the windshield based upon the monitored electrical property of the resistance element. Also, a temperature calculator can be used to determine a temperature based upon the monitored electrical property associated with the resistance element and upon a relationship between resistance and temperature that has been stored in a memory device.Type: GrantFiled: October 9, 1997Date of Patent: February 1, 2000Assignee: Lear Automotive Dear Born, Inc.Inventors: Kyi-Shin Shiah, Timothy J. Bomya
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Patent number: 5990460Abstract: A method and apparatus for changing an automatic cooking program in an electric oven is disclosed. A parameter of the cooking program, such as cooking time, is automatically altered in response to a property of the electricity supplying the oven, such as line voltage. The method and apparatus are particularly well suited for use in ovens utilizing halogen tungsten lamps as sources of heat.Type: GrantFiled: January 31, 1997Date of Patent: November 23, 1999Assignee: Amana Company, L.P.Inventors: Jonathan Scott Petty, Jennifer Lynn Tarplee
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Patent number: 5949960Abstract: Multiple resistance type electric heating elements projecting into the interior of the storage tank portion of an electric water heater are protected against dry firing damage by using a water soluble member, representatively a sugar cube, positioned in the empty tank and blocking the spring-driven movement of a switch closure member that maintains an electrical circuit in an open state preventing electrical current flow through any of the heating elements. When the tank is initially filled with water the sugar cube dissolves, thereby unblocking the switch closure member and permitting it to be spring-driven into a circuit closing position to permit electrical current flow through the heating elements.Type: GrantFiled: July 21, 1997Date of Patent: September 7, 1999Assignee: Rheem Manufacturing CompanyInventor: Jacob H. Hall
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Patent number: 5943475Abstract: An improvement in electrical elements for a water heater includes a mass attached to the element for reducing the deposition of hard water scale on element surfaces, particularly in the return bend areas. In one embodiment, a flow accelerator tube encloses the element. The flow accelerator tube has an inlet at one end and an outlet at a higher elevation at the opposite end. Water is induced to flow through the tube because of temperature change. In another embodiment, a solid mass with high surface area encloses the return bend areas to increase heat transfer at a lower temperature to reduce scaling and increase element life.Type: GrantFiled: November 6, 1998Date of Patent: August 24, 1999Assignee: Water Heater Innovations, Inc.Inventor: Barry N. Jackson
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Patent number: 5900176Abstract: A temperature sensitive protective device for a solar water heater comprising an electric heater (12) for heating water and an electrical circuit for controlling electrical power to said electric heater. A first switch (22) in the circuit controls electrical power to the electric heater and an actuator is moveable to an activated position for operating the first switch means (22) to discontinue electrical power to the electric heater. A fusible link (24) is attached to the actuator for preventing the actuator from operating, and a second switch is disposed in the said circuit for controlling electrical power to the fuisible link when actuated for breaking the fusible link to release the actuator. A safety thermostat senses the temperature of the water and actuates the second switch in response to a predetermined temperature of the water and a biasing operates the actuator upon the release of the actuator by the fusible link.Type: GrantFiled: September 2, 1997Date of Patent: May 4, 1999Assignee: Hardie Energy Products Pty LtdInventors: Phillip Graham Tassicker, Friedrich Edward Berrer
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Patent number: 5886323Abstract: A temperature regulated manicure bowl is provided having a temperature control channel and an heating channel. The heating channel is provided to heat water to a preset temperature level. The temperature control channel is provided to control the heating channel, thereby regulating the temperature of the water. The temperature regulated bowl is also provided with a monitoring channel that monitor's the temperature control channel and the heating channel to insure proper operation. Additionally, a disposable sheath is provided to fit over the bowl. The disposable sheath is a means to prevent the spreading of hand born infections.Type: GrantFiled: March 3, 1997Date of Patent: March 23, 1999Inventor: Annie Hivale
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Patent number: 5880438Abstract: A steam sterilization apparatus (10) includes an electronic control system having a main control circuit (C) including a central processing unit (68), an input device (36), and output devices (24,28) provided on a single circuit board (22) which is attached to a front bezel (16) of the sterilizer (10). The sterilizer (10) includes a flash steam generator (56). The main control circuit (C) implements an over-temperature feedback circuit (160) that disconnects the heating elements (162) in the steam generator (56) from electrical power when an over-temperature condition is detected. Isolated feedback is provided to the central processing unit (68) confirming the heating element disconnection operation. The control system includes error switches (82, 86, 88) that detect various error conditions. Upon an error condition being detected, the steam supply to the steam sterilization chamber (12) and/or to the pressurized steam seal (42) of the apparatus (10) is halted.Type: GrantFiled: April 4, 1997Date of Patent: March 9, 1999Assignee: Steris CorporationInventors: Mark J. Parrini, David F. McCall, Francis J. Zelina, Terrence L. Lukas
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Patent number: 5861610Abstract: An improved heater wire and electro-thermal controller suitable for use in electric heating appliances such as electric blankets and heating pads. The heater wire is formed with a first conductor for heat generation and a second conductor for sensing. The first conductor and second conductor are wound as coaxial spirals with an insulation material electrically isolating the two conductors. The two spirals are counter-wound with respect to one another to insure that the turns cross, albeit on separate planes, several times per inch. With the conductors thus formed, if the insulation separating the conductors fails, the first and second conductors will come into electrical contact to facilitate detection of this hazardous condition. The controller of the present invention includes an electronic control unit a sensor input circuit, a heater driver circuit and a user interface circuit.Type: GrantFiled: March 21, 1997Date of Patent: January 19, 1999Assignee: Micro Weiss ElectronicsInventor: John Weiss
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Patent number: 5856654Abstract: A safety device associated with a heating element of a glass ceramic cooking hob and arranged to prevent overheating of the cooking hob, the element comprising an insulating body defining a seat containing at least one heat generator, the device comprising a measuring member arranged to measure the temperature of the heating element and to deactivate the operation of the heat generator whenever this temperature exceeds a predetermined value, the measuring member being associated externally with a side wall of the insulating body and having a measuring part connected to a body passing through said wall and projecting to a limited extent above the heat generator.Type: GrantFiled: October 24, 1997Date of Patent: January 5, 1999Assignee: Whirlpool CorporationInventors: Luca Frasnetti, Davide Cabri, Guido Gagliardi, Daniele Valassina
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Patent number: 5847367Abstract: The temperature of a heating element (3), which heating element has a temperature dependent resistance, is measured by comparing the current through it with a user adjustable reference value. The AC voltage across a current sensing resistor (7) in series with the heating element (3) is compared in a comparator (9) with a reference AC voltage generated at a tap (6) of a voltage divider (8). The phase of the logic output signal of the comparator (9) indicates a first state in which the heating element (3) is too hot or is not conducting, or a second state in which the heating element (3) is too cold and conducting. A second comparator (16) detects whether or not the heating element (3) is conducting. A logic gate (18) and a latch (17) switch on the current through the heating element (3) in response to timed pulses from a timing circuit (15) and switch off the current through the heating element (3) when the heating element (3) is conducting and too hot.Type: GrantFiled: June 11, 1997Date of Patent: December 8, 1998Assignee: U.S. Philips CorporationInventors: Philip T. Hancock, John S. Crawford
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Patent number: 5814791Abstract: An electrical assembly (10) comprising a first electrical device (12) comprised of a non-linear resistant, temperature responsive element (14) and first and second electrodes (16,18), the device (12) being connectable to a first power supply (20) such that a first electrical current (i.sub.1) travels through the resistive element (14) from the first electrode (16) to the second electrode (18). A second electrical circuit (24) is in electrical contact with the electrical device (12) such that the second circuit (24) may introduce a secondary electrical current (i.sub.2) into a localized portion of the non-linear resistant element (14), the second current (i.sub.2), when applied to the non-linear resistant element (14), causes the element (14) to change from a first resistant state to a second resistant state.Type: GrantFiled: June 17, 1997Date of Patent: September 29, 1998Assignee: Littelfuse, Inc.Inventor: Wallace C. Rudd
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Patent number: 5811765Abstract: A heater includes a first heat-generating conductor, a second heat-generating conductor and a shield conductor. The first heat-generating conductor and the second heat-generating conductor are integrally covered with the shield conductor. One end of the first heat-generating conductor and one end of the second heat-generating conductor are electrically connected to each other. When a current is applied from the other end of the first heat-generating conductor, the current flows in the first heat-generating conductor and the second heat-generating conductor in opposite directions. A negative potential -Vn is applied to the shield conductor from a negative potential generating circuit. A positive potential terminal connecting circuit is composed of two diodes. One of the diodes has its anode connected to the positive potential terminal of the negative potential generating circuit and its cathode connected to a first line.Type: GrantFiled: December 23, 1996Date of Patent: September 22, 1998Assignee: Osaka Nishikawa Co., Ltd.Inventors: Takeshi Nakagawa, Kosaku Mitani
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Patent number: 5808277Abstract: A domestic electric water heater comprises a cylindrical tank having a vertical wall and a curved bottom, the latter defining with the vertical wall an annular stagnant water zone susceptible of bacterial contamination by, for example, legionella bacteria. The tank is provided with an upper immersion heating element and a lower immersion heating element, the latter being located above to the annular zone of contamination. The programmable thermostat turns on the lower immersion element until the preset temperature is sensed by the temperature sensor at the upper immersion heating element. This concept elevates the whole tank including the annular zone of contamination to a higher temperature setting and thus eliminate the danger of bacterial contamination.Type: GrantFiled: June 13, 1996Date of Patent: September 15, 1998Inventors: Nazir Dosani, Nizar Ladha
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Patent number: 5790009Abstract: An electric coffee maker having a hot water heater, a resettable thermostat, a mechanism for resetting the thermostat, and an electrical switch connected in series with the thermostat. The resetting mechanism has a user actuated button movably mounted to a housing of the coffee maker and a lever connected to the button. The lever moves a plunger of the thermostat when the button is moved by a user. The switch has an actuator located under a portion of the button that is moved by the button, to open the switch, when the button is moved towards a thermostat reset position.Type: GrantFiled: January 21, 1997Date of Patent: August 4, 1998Assignee: Black & Decker Inc.Inventor: Mark D. Jackson
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Patent number: 5770836Abstract: A safety-assuring control device for an electric blanket which includes a PTC heater includes an integrated circuit microcontroller unit having first and second safety circuit inputs and an output connected to a control input of an electrically controlled heater switch. A neon tube is connected between the primary safety link return conductor of the heater and the first safety circuit input, to indicate whether there is a first type of fault in the PTC heater. A connection between the second safety circuit input and the secondary safety link return conductor of the PTC heater is provided which indicates whether there is a second type of fault in the heater. The microcontroller unit includes a preliminary fault detection circuit for supplying a limited power test signal in a test mode to the heater for a predetermined period of time prior to a full power operation of the heater.Type: GrantFiled: November 8, 1996Date of Patent: June 23, 1998Assignee: Micro Weiss ElectronicsInventor: John Weiss
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Patent number: 5756969Abstract: A heating control device of an image forming apparatus determines a phase of heat control in accordance with a target temperature and a current temperature of a fixing roller and a change status of the current temperature, determines a control unit period tp, a main heater turn-on time tm, a sub-heater turn-on time ts and Duty No. in accordance with a count of a counter which counts the number of control units which are unit periods of control and a shift status of phase, and finally determines a type of control and supplies powers to the main heater and the sub-heater.A proper heater power to control to a target temperature can be applied in a short period and a temperature ripple is reduced.Type: GrantFiled: October 30, 1996Date of Patent: May 26, 1998Assignee: Canon Kabushiki KaishaInventors: Hitoshi Machino, Kiyoto Toyoizumi, Masayoshi Takahashi
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Patent number: 5739504Abstract: A control system for use with a boiler and associated burner. In one embodiment, the system comprises a first control circuit for producing a signal having alternating first and second states, the first state activating the burner and having a first predetermined duration, the second state deactivating the burner and having a second predetermined duration that defines a time period that allows foam and surging fluid in the boiler to settle, and a relay responsive to the first control circuit signal and adapted for connection to a power source and the burner, when the first control circuit signal has the first state, the relay connects the power source to the burner to activate the burner, when the first control circuit signal has the second state, the relay disconnects the power source from the burner to deactivate the burner.Type: GrantFiled: July 28, 1995Date of Patent: April 14, 1998Assignee: C. Cowles & CompanyInventors: Richard A. Lyons, Christopher L. Murray
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Patent number: 5723847Abstract: A method and an electronic control unit for determining and optionally displaying the remaining time in a treatment program in a household appliance include superposing an initializing test program segment on the treatment programs in order to determine an "installed heating capacity" parameter that determines a gradient. To that end, a defined quantity of the medium is heated with an electrical heater for a predetermined period of time. The "installed heating capacity" parameter and/or a comparison value corresponding to its magnitude is calculated from the attained temperature increase, the defined quantity of the medium and the known period of time and is stored as an operand in a nonvolatile memory for later remaining-time determinations.Type: GrantFiled: August 7, 1996Date of Patent: March 3, 1998Assignee: Bosch-Siemens Hausgeraete GmbHInventor: Frank Boldt
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Patent number: 5712467Abstract: A heated galette is provided with a heating unit and a temperature sensor connected in a control circuit with the heating unit to maintain a certain temperature of the surface of the galette on which a synthetic yarn is guided. The control circuit is disconnected periodically or intermittently so that the heating unit can be heated independently of the feedback control provided by the control unit. Upon the heating unit attaining an equilibrium with temperature, a first actual value temperature is measured and a difference is obtained from a setpoint temperature corresponding to a given control ratio and a signal representing the difference is generated. Utilizing this system, it is possible to detect failure of the temperature sensor and/or the heating unit or inappropriate positioning of the temperature sensor.Type: GrantFiled: April 11, 1996Date of Patent: January 27, 1998Assignee: Zinser Textilmaschinen GmbHInventors: Derrick Straka, Gunter Konig
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Patent number: 5710408Abstract: The invention is directed to an ice and snow melting system. At least one sensor is provided, with each sensor being configured for sensing a temperature or moisture associated with an ambient environment and providing a signal indicative thereof. A heater for melting the ice and snow includes at least two electrical conductors associated therewith. An automatic controller is connected to the at least one sensor, and includes a ground fault circuit interrupter in communication with at least two of the electrical conductors associated with the heater. The ground fault circuit interrupter detects a ground fault condition associated with the heater and provides a signal indicative thereof. The controller selectively controls operation of the heater dependent upon the sensor signal and/or the ground fault circuit interrupter signal.Type: GrantFiled: August 15, 1996Date of Patent: January 20, 1998Assignee: MSX, Inc.Inventor: Thaddeus M. Jones
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Patent number: 5702624Abstract: A heat treatment control system to cure a photoresist that is deposited upon a semiconductor substrate is described. The heat treatment system has a hot plate with a heating element and temperature sensing devices that are in close proximity to the semiconductor substrate. The heat treatment system also has a controlling device that will selectively provide an electrical power source to the heating element to heat the semiconductor wafer. The coupling of the heating element to an electrical power source is determined by an electrical signal from one of the temperature sensing devices that have been conditioned and compared to a set temperature signal to provide an error signal. The controlling device will examine the error signal and adjust the temperature. An over temperature alarm circuit is connected to the second temperature sensing device.Type: GrantFiled: October 9, 1996Date of Patent: December 30, 1997Assignee: Taiwan Semiconductors Manfuacturing Company, LtdInventors: Ching-Wen Liao, Chin-Chuan Kuo, Chi-Kang Peng, Tsun-Ching Lin
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Patent number: 5681495Abstract: An alternator power-supply type electric heating control apparatus, comprising (1) a switch for switching an output of an alternator including a field coil, a stator coil, and a rectifier to a first state where the output is connected to a battery and vehicle-mounted electrical load side or a second state where the output is connected to an object to be heated which is heated by current conduction; (2) a controller which performs an output control of the alternator by a duty control of a field current that is supplied to the field coil, performs the switching of the switch, detects a failed state, and causes a display unit to display the failed state to warn a driver; and (3) an object to be heated voltage control unit for controlling the duty control of the field current by a rectification wave of one phase of an output voltage of the alternator, rectified by the rectifier, so that a voltage of the object to be heated does not exceed a predetermined value.Type: GrantFiled: December 29, 1995Date of Patent: October 28, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Kenichi Tsuchiya, Toru Fujiwara
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Patent number: 5679274Abstract: The disclosure involves a countertop distiller for home use. Such distiller is of the type including a condensing coil and an electrically-powered water heater. A method for controlling power flow to the heater includes the steps of activating a timer circuit to energize the heater, increasing the temperature of the coil and bypassing the timer circuit when the coil temperature increases to a predetermined value. The heater is de-energized when the water in the raw water container is substantially depleted and the heater temperature increases to a predetermined value because of such depletion. A new electrical circuit for a countertop distiller is also disclosed.Type: GrantFiled: May 13, 1996Date of Patent: October 21, 1997Assignee: The West Bend CompanyInventor: Michael A. Mahood
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Patent number: 5674422Abstract: A system comprising a microprocessor and a reset and watchdog circuit. The microprocessor generates a first pulse train (P1) to indicate the correct operation of the microprocessor and the reset and watchdog circuit generates a reset signal (RST) in response to an irregularity in the occurrence of the first pulse train. The first pulse train is a substantially synchronous software copy of a second pulse train (P2) which is received by the microprocessor and which is preferably a limited a.c. supply voltage signal. This copy is generated by an appropriate programming of the microprocessor. The reset and watchdog circuit receives the first pulse train (P1) and the second pulse train (P2) and supplies the reset signal (RST) in response to a disturbed synchronism between the occurrence of the first pulse train and the second pulse train.Type: GrantFiled: April 5, 1995Date of Patent: October 7, 1997Assignee: U.S. Philips CorporationInventor: Harry Marinus
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Patent number: 5670074Abstract: A safety apparatus for shutting off a unit having a manually operated power interruption switch or fuel supply valve upon detecting a predetermined condition where the condition is detected remotely from the location of the switch or valve. The sensor for detecting the predetermined condition communicates with a receiver that contacts an actuator for opening the interrupt switch or closing the fuel supply valve without an interconnecting electrical wire.Type: GrantFiled: January 18, 1995Date of Patent: September 23, 1997Inventors: Carl F. Kass, Arthur W. Little
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Patent number: 5667711Abstract: A solenoid trip unit is electrically connected in parallel with a current limiting polymer element in series with circuit breaker contacts to function as a shunt resistance for the polymer element, becoming energized by transition of the polymer element to its high resistive state, for tripping the breaker contacts open upon such transition. The solenoid may be particularly wound with a resistive wire.Type: GrantFiled: May 20, 1996Date of Patent: September 16, 1997Assignee: Eaton CorporationInventors: Hemant K. Mody, William E. Grass
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Patent number: 5664481Abstract: A toaster having a movable bakery product shield for enhanced toasting quality. A wide slot cavity to receive bakery goods for toasting is defined on one side thereof by an upstanding, stationary product retainer spaced apart from a heating element and, on the other side thereof, by a movable product retainer having a deflector shield connected along its upper edge. Interiorally of the toaster, a carriage mechanism is mounted on an end wall for vertical reciprocal movement between an up position and a down position. Connected to the carriage mechanism and extending longitudinally through the slot cavity is a bread support shelf which is inclined toward the stationary product retainer to cause the lower edge of a bread slice placed in the toaster slot to engage the stationary product retainer.Type: GrantFiled: November 19, 1996Date of Patent: September 9, 1997Assignee: Toastmaster Inc.Inventor: Peter Huggler
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Patent number: 5644974Abstract: An electric toaster having an automatic resetting heat reduction assembly. The toaster includes one or more cavities to receive bagels, bread, or other food products, and a plurality of heating elements located within the cavities to toast the food products. A carriage assembly movable between a raised nontoasting position and a lowered toasting position lowers and raises the food products into and out of the toasting cavities. When lowered to the toasting position, the carriage assembly activates a heat activation assembly which completes an electrical circuit between a power source and the heating elements, thereby energizing the heating elements to toast the food products. The toaster also includes a heat reduction assembly settable between an original full heat position and a depressed reduced heat position.Type: GrantFiled: November 21, 1996Date of Patent: July 8, 1997Assignee: Toastmaster, Inc.Inventor: Timothy J. Slavin
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Patent number: 5632917Abstract: A windshield heating system includes a heating element installed in the defroster ductwork of a motor vehicle. An electrical driver provides electrical power to heat the heating element, thereby immediately providing heated air to the windshield of the vehicle when the vehicle is started in cold weather. The electrical power provided to the heating element can be modulated based on (1) temperature of the air before the heating element, (2) temperature of the heating element, and (3) system voltage of the vehicle.Type: GrantFiled: August 8, 1994Date of Patent: May 27, 1997Assignee: Ford Motor CompanyInventors: James M. Cummins, Gene R. Burnham, William A. Oestreich, James D. Boka