Abstract: A control device for controlling the heating capacity of the heating element of a cooking or heating plate, on which a cooking vessel, roasting vessel, or the like, can be placed and heated. The temperature on or in the cooking vessel is determined by means of a temperature sensor, conveyed to a logic circuit, and used in this for the control of the heating element by means of an output stage in dependence on the actual temperature determined and/or the temperature increase in the heating phase. In order for control of the heating output of the heating element to also be performed during a roasting process with a roasting pan placed on the cooking or heating plate, a program selection switch provided to select between various cooking processes, such as rapid simmering, steaming, warming and the like has a coordinated switching position for each and for a roasting process has an additional switching position.

Abstract: The present invention relates to controllable electric heaters, in particular heaters employing tungsten halogen lamps and suitable for use in cookers of the type having a ceramic hob below which are placed the heaters.It is an object of the present invention to provide a controllable electric heater employing two tungsten halogen lamps and other components of an inexpensive nature and which allows six different power settings to be obtained.

Abstract: A humidifier boiler has a plurality of electrodes supplied with electric current through circuitry which includes at least one solid state switch or relay such as inverse parallel thyristors or triacs arranged to switch at zero voltage so that, when the humidifier is called upon to vary the quantity of water vapor output from the boiler through an outlet pipe in response to a control signal from a humidity controller, the control signal causes the duration of the "on" and/or "off" periods of the, or each, solid state switch or relay to be varied in order to vary the power to the electrodes.

Abstract: There is provided a molded connection piece and a method of making the same, in particular a boring saddle made of thermoplastic material and having a heating wire capable of conducting an electric current for producing a welded joint between the molded connection piece and an object to be joined with the molded connection piece. The heating wire is embedded in both surfaces of a disk-shaped core, in each case following the course of a spiral-shaped groove, and the core having the heating wire is joined with the molded connection piece. The disk-shaped core is formed of a material which, on melting, combines itself with the material of the molded connection piece.

Abstract: The invention relates to a control and switching apparatus for electric heating, comprising a micro-processor-based operation control unit (2) provided with control switches, and a regulating circuitry unit (5) associated with said control unit and comprising a plurality of regulating circuits. At least some of the regulating circuits are connectable to electronic sensors (8), whereby the combined effect of measuring messages fiven by said sensors, control data from the operation control unit (2) as well as set values (6) selected by the regulators provides the basis on which the regulating circuits (5) are adapted to control the ON/OFF-switches of electric loads, said switches being triac-switches (9a). One regulating circuit can be modified to operate as a regulating circuit suitable for controlling an electric sauna stove, said circuit being connectable, by means of a selector device, in power transposition with one or several other regulating circuits.

Abstract: An improved data entry and control arrangement for an appliance which includes an electronic display having a plurality of digits. User actuable up and down keys enable the user to adjust the value displayed. The control changes the display by a first amount, for example, one minute for a time display, in response to each momentary actuation of an up or down key. In response to continuous actuation, the control, after initially changing the display by the first amount, then switches the least significant digit of the display to zero and thereafter periodically changes the display by a second amount evenly divisible by ten, such as for example 10 minutes. The preferred update interval between changes is on the order of 0.45 seconds duration. The control also enables the user to change the update interval.

Abstract: A power control arrangement for controlling the power output of a plurality of resistive heating elements (9a, 9b) comprises a multi-position switch (S1, S2) for connecting the heating elements in series and in parallel, a zero voltage switch (4), AND-gate (5), clock pulse generator (6), shift register (7) and semiconductor device (8) such as a trail which cooperate to vary the duty cycle applied to the heating elements in both serial and parallel modes.

Abstract: A method of controlling a-c power by means of thyristors for resistive electric furnace for achieving a temperature control thereof, comprises providing an output which varies between O and N cycles in response to an input analog signal which also varies between 0 and 100% by a burn-on and -off control at zero crossings of an a-c power source. According to the invention, the output is uniformly distributed throughout a control period comprising N cycle times. The output pattern is transit to another output pattern in response to a new analog input signal at the desired point in time.

Abstract: A parallel circuit heating tape (13) of the kind comprising two electrical power conductors (12,15) with low resistance relatively thin heating elements (16) between them which dissipate heat, the tape (13) comprising a temperature monitoring conductor (18,25) which extends alongside one of the power conductors (12,15), the temperature monitoring conductor (18,25) being separated from the one power conductor (18,25) by a substance (23,28) which insulates the two conductors (12,18; 15,25) from one another when the temperature is below a specified temperature or temperature within a transition temperature range, and provides a current path from one conductor (12,14) to the other (18,25) when the temperature is above the specified temperature or temperature within the transition temperature range.

Abstract: A cyclable electrical switch construction, a system utilizing the switch construction and methods of making the same are provided, the cyclable electrical switch construction comprising a housing having a cyclable electrical switch therein and a rotatable actuator shaft that extends from the housing for setting the duty cycle of the switch in relation to the rotational position of the shaft in either rotational direction thereof from an "off" position thereof, and an electrical switch unit being carried on the housing and having structure operatively interconnected with the shaft so that the switch unit is actuated from one condition thereof to another condition thereof only when the shaft is rotated from the "off" position thereof in one rotational direction thereof. The cyclable electrical switch is used in a plural load circuit, preferably, as a control of a dual wattage heating element of a cooking unit.

Abstract: A toaster oven/broiler is provided with a visual indicator which is continuously illuminated when the device is in the toast, oven or broil mode. The indicator is not extinguished when the device is in the oven mode and thermostat switch contacts open to deenergize the heating elements.

Abstract: A low cost system for permitting the remote load management control of electrical residential room heating units that is compatible with existing heating systems of the type wherein each room heating element is controlled by a manually settable line voltage thermostat responsive to ambient room temperature. Included in the system is a normally closed low voltage operable thermal relay included immediately downstream of a resident circuit breaker and in the power transmission line for each room heating element and an associated single user programmable set back thermostat for shifting said thermal relays from normally closed to open position in response to residential dictated parameters of operation capable of also being operated in response to a remotely generated signal from a load management control center.

Abstract: A combined electric sauna stove and sauna room heater having a plurality of electrical resistors and electrical circuitry for controlling the current supply to the resistors. In order to eliminate the need of separate room heating elements in the sauna room, the electric sauna stove is provided with a heating resistor for maintaining a normal room temperature in the room where the stove is located while the room is not used for bathing. This heating resistor may be a room heating resistor separate from the electrical resistors of the stove or it may be formed by connecting in series two or three of the electrical resistors of the stove.

Abstract: Load resistors connected in parallel in a heating circuit having switches operable to connect and disconnect the resistors from a common supply line for heating a plurality of zones to maintain predetermined temperatures therein, are tested by disconnecting all of the load resistors from the supply line to begin a testing operation. Any current conducted when all load resistors are disconnected from the supply line is measured, after which the load resistors are then individually and successively reconnected to the supply line. The current then conducted from the supply line in succession to the load resistors is measured and compared with reference values of current through the load resistors when functioning properly.

Abstract: A method of controlling several clocked loads controllable individually and independently of each other, more particularly heating loads of an electric oven, for minimizing the demand on an alternating current mains due to switching transients. More particularly, the loads are energized in sequence to prevent flickering when the loads are coupled to a common phase of the alternating current mains are switched on each time at the beginning of their clock period. The clock periods of the various loads are of equal length. All loads neither switched off nor switched to full power in a switching cycle are connected to the mains so as to be interlinked in time in a manner such that, when the preceding load is switched off, the next load is switched on. Such a switching cycle is started again each time at the beginning of a common clock period independently of the length of the switching cycle.

Abstract: Uniform electrical heating of a circular, single crystal germanium window (18) uses its bulk resistance and pairs of electrodes (20) equally spaced about the window's periphery. The electrode pairs are sequentially switched at a rate high enough to avoid thermal switching transients.

Abstract: An improved power control system for a household cooking appliance of the type having a glass ceramic cooking surface and at least one radiant heating unit disposed beneath the cooking surface operable at a plurality of user selectable power settings. At least one of the power settings has associated with it predetermined maximum and minimum reference temperatures defining a temperature band representative of the steady state temperature range for the glass ceramic support surface proximate the heating unit when heating normal loads at that power setting.

Abstract: An all solid state timer-controller for the timed, sequential application of electrical current to loads within a circuit at high amperage, the circuit finding utility in the application of electrical current to de-icers employed aboard aircraft.

Abstract: A power control switching arrangement for controlling energization of a load in response to an external controller, in which a first semiconductor switch is connected in parallel with the series combination of a first normally open thermally actuated switch and a second normally closed thermally actuated switch, to couple the power signal to the load. A first heater for the first thermal switch is connected in parallel with the load. A second heater for the second thermal switch is connected in series with a second semiconductor switch, across the power supply. The second semiconductor switch, when switched into conduction by the controller, enables energization of the second heater. To energize the load, the controller switches the first semiconductor switch into conduction enabling energization of the load and the first heater. Energization of the first heater closes the first thermally actuated switch, thereby shunting the first semiconductor switch.

Abstract: An improved temperature sensor failure detection arrangement for a temperature controlled heating device of the type having a heater, an electronic controller for controlling the power level applied to the heater, and a temperature sensor. The controller includes an internal heater energy counter, which is incremented and decremented at rates determined as a function of the power level applied to the heater such that the count of the heater energy counter approximately tracks the temperature of the heater. The controller periodically compares temperature information from the temperature sensor with the count of the heater energy counter to check for abnormal operating condition of the temperature sensor.

Abstract: An improved electric cooking appliance with a plurality of heating units arranged in two groups, a first group adapted for energization by a first AC power signal and a second group adapted for energization by a second AC power signal, 180.degree. out of phase relative to the first power signal. The heating units of the first and second groups are each connected to a common neutral power line.

Abstract: Method and device to supply, from a source of alternating voltage (5a or 5b), a thermal printing head (3) comprising a number of heater units (3a, 3b).The device comprises a means (6a to 6d) of obtaining a rectified voltage, a means (8) of detecting the points when the alternating voltage or the rectified voltage change to zero and to produce a detection signal, a means (9) of synchronizing, with this detection signal, the heating of particular heater units and a means (7a, 7b) to absorb current.

Abstract: An electric power control device is composed of plural resistor loads (1.sub.0 -1.sub.4) the heat-generating powers of which are different from one another, switch means (3.sub.0 -3.sub.4) connected in series to each of the resistor loads and adapted for the ON-OFF control of an ac power (2), and means (4.sub.0 -4.sub.4) for ON-OFF controlling the switch means so as to turn on or turn off the ac power and also for selectively controlling the individual resistor loads so as to adjust the heat-generating powers of all of the resistor loads in accordance with their corresponding desired heat-generating powers.

Abstract: A control system for a thermal print head includes means for regulating the firing of the print elements with the proper pulse width to compensate for increasing substrate temperature. The control circuit is divided into two separate circuits--the driving circuit for turning the print elements on and off, and the decision-making circuit which executes the substrate temperature coding and control codes and sends control signals to the driving circuit. Three types of temperature compensation are utilized in the control program. A tailored pulse width is used for each bank of the print elements to compensate for various element resistances. As the print head shuttles across the record medium, the pulse width is reduced for each horizontal dot position. The pulse width also is reduced for each line printed in the format. The system may be used for either direct thermal or thermal transfer printing with both full and half dot spacing and single or double width characters.

Abstract: A humidity detector includes a first heat-sensing element for an electric signal corresponding to the temperature of steam to be detected and a second heat-sensing element for an atmosphere temperature whose vapor is to be detected or a temperature close to it. A comparator compares the electric signals from the first and second heat-sensing elements. The vapor detection characteristics may be adjusted through variation in the heating temperature of the first heat-sensing element.

Abstract: A device for monitoring operational condition of electrical consumers in a motor vehicle, particularly of heater plugs of a diesel engine, includes inductances connected in series between respective heater plugs and their d.c. supply. Alternating or pulsating current is supplied to a connection point of the inductances with the d.c. supply, and potentials across the inductances and the heater plugs are simultaneously evaluated to indicate a defective heater plug.

Abstract: A radiant heater for cooking appliances with a glass ceramic plate has both bright light-radiating heating elements such as high temperature halogen lamps emitting substantial radiation in the visible range, and also darker glowing radiating elements operable at lower temperatures and radiating emitted light primarily in the infrared region. The bright visible light radiating element and the darker infrared glowing elements are connected in series with one another, whereby the series resistance of the dark or infrared radiator limits initial current loading, and after the radiant elements reach operating temperatures, the infrared radiant element assumes a reduced portion of the total resistance. The visible light and glowing infrared series-connected elements can be interleaved or the visible element can define a boundary for a cooking element.

Abstract: In the case of an electric cooker with at least two electric hotplates having several heating resistors and controlled via separate power control devices, one hotplate has a high power additional heating resistor for an initial cooking operation. While intermediately connecting a temperature switch and an additional contact of the associated power control device, the additional heating resistor is connected to the electric mains via a further additional contact. The further additional contact is a component of the power control device of the other electric hotplate and is only closed if its power consumption drops below a predetermined switching value.

Abstract: A controller for controlling an electrode boiler steam humidifier, of the type operable from a source of polyphase alternating current, is provided. A plurality of current loop transformers, coupled to the boiler electrodes, sense the individual currents drawn in each phase of the polyphase alternating current. A plurality of full-wave bridge rectifiers individually couple the secondaries of the current lube transformers to the input of a voltage amplifier such that the output of the amplifier is indicative of the highest of the currents sensed in each phase of the boiler electrode current. When the output of the voltage amplifier exceeds a predetermined threshold, a control effect is produced such that operation of the humidifier is controlled in accordance with the highest of the individual phase currents drawn through each of the boiler electrodes.

Abstract: Power-processing unit uses AC buses (30, 32) to supply all current dependent needs such as connections (54, 56) to an ion thruster through an inductor (88) and the primary of a transformer (90), to assure limited currents to such loads. Where temperature control is also required, such as to the main discharge vaporizer heater connection (36, 38), switches (100, 102) are serially connected with inductor (96) and the primary of transformer (98). Temperature sensor (104) controls the switches (100, 102) for temperature regulation.

Abstract: A power control arrangement particularly applicable to a multiple surface unit cooking appliance providing a griddle heated by the combination of a standard surface unit and an automatic surface unit. Temperature information for the standard surface unit is provided by a counter implemented in the controller which is incremented and decremented at rates which cause the count to approximately track the griddle temperature proximate the surface unit.

Abstract: An improved touch control circuit arrangement for electrical appliances having one or more electrical loads to be individually controlled in accordance with user selected power settings. Each load has associated with it a power relay for coupling the load to an external power supply. Each relay is coupled to a latch circuit operative when set to close the relay and when reset to open the relay. The touch control arrangement includes a matrix array of touch keys having an input line for each row and an output line for each column to facilitate the multiplexing of touch key information to the microprocessor in conventional fashion. However, the OFF keys are continuously enabled and coupled to the reset input of the associated latch circuit such that user actuation of an OFF key directly resets the relay control circuit for the associated load. This enables the user to turn off the load independent of the microprocessor.

Abstract: An electric double oven having two self-cleaning cavities, one cavity also having microwave capability wherein forced air from a blower repels hot self-clean air from entering the waveguide. A circuit is provided for limiting the temperature of either cavity to approximately 505.degree. F. when the other cavity is above a temperature associated with self-cleaning. The circuit also limits the common microwave cavity to approximately 505.degree. F. when the blower is not functioning so that oven cavity air entering the waveguide will not present a hazard.

Abstract: A heating power source device includes a pair of loads connected to a secondary side of a power source transformer by way of four thyristor units. Each of the thyristor units includes pair of thyristors connected in anti-parallel relationship to each other and is controlled so as to connect the loads in parallel relationship to each other at the beginning of energization and then to connect the loads in serial relationship to each other after the resistance of the loads has been reduced below a predetermined level.

Abstract: A display arrangement for a cooking appliance using a heater energy counter based power control system which provides a user discernible signal signifying that the appliance heating element has reached the steady state temperature associated with the user selected power setting. The heater energy counter is selectively incremented or decremented at a rate in accordance with the selected power setting such that the count rate is approximately proportional to the rate of increase or decrease respectively of the temperature of the heating element for the power setting selected. When so incremented and decremented the count of the counter provides an approximation of the actual heating element temperature. The display arrangement generates a user discernible signal when the count of the heater energy counter indicates that the associated heating element has approximately reached the steady state temperature for the selected power setting.

Abstract: In a blackbody furnace comprises a furnace provided with at least one aperture at an end along a horizontal direction with the interior thereof being hollow and a polyhedral heating unit is provided enveloping the furnace, each surface of the aperture, target and side surfaces of the heating unit is divided into two or three zones, and these zones of the heating unit are controlled in such manner that the temperature of the aperture comes to have a prescribed relationship with respect to the temperature of the target of the blackbody furnace, whereby the effective cavity emissivity of the blackbody furnace is always unity.

Abstract: An electrical heating system for buildings is described in which the output voltage to a resistance heater is varied in accordance with outside temperature. The disclosure includes system means for compensating for solar radiation and wind effects. Also, night setback and morning start up are provided. The heat present on the interior of the building is provided in accordance with the building characteristics and without regard to interior temperatures.

Abstract: A heating power supply apparatus for polycrystalline semiconductor rods, including a power transformer and anti-parallel thyristor unit groups connected to respective portions of the secondary of the power transformer, balance transformer groups connected to the anti-parallel thyristor groups and combined to make constant a secondary current of each of the balance transformers, and semiconductor rod connecting terminals connected to the secondaries of the balance transformer groups, respectively. The balance transformer groups are divided into a group of plural balance transformers of small current and high voltage for exclusive use during the starting and a group of plural balance transformers for taking over operation from the group of balance transformers of small current and high voltage and continuing subsequent operations.

Abstract: A method of controlling a space heating system having a plurality of electrical resistance heaters includes the steps of computing the aggregate number of resistance heaters required to be energized to raise the actual temperature within a space to a set point temperature. This aggregate number may have integer and fractional components. One of the resistance heaters, denominated a controlled heater, is adapted both for continuous energization or for modulated control by intermittent energization. A group of second resistance heaters is adapted for continuous, staged energization, this group including a number of heaters equal to the integer component. Energization of the heaters comprising this group is preferably sequential after the lapse of a preselected interstage time delay between energization of the controlled heater and the first heater of the group.

Abstract: A perimeter heat loss control system for electrical heaters and/or radiant ceiling panels around the periphery of a building has the heaters divided into zones, usually one zone for each outside wall. In a zone, a radiant heat responsive heat flow sensor faces the outside wall for the zone and generates a wall heat rate signal; a thermal sensor is positioned adjacent to one heater to generate a heat rate signal. A zone comparator uses the sensor signals to generate an error signal representative of deviation of the differential between the rate of heat flow through the zone wall and the rate of heat generation in the zone relative to a predetermined preset value. That error signal is applied to a power control to control all heaters in the zone, proportionally varying the input to the heaters until a balanced heat loss condition is realized.

Abstract: The oven includes a muffle 1 in which are mounted at least one upper heating element 11b, 11b, at least one lower heating element 14, an air circulating fan 4 provided in the rear wall 3 of the muffle 1, a heating element 6 placed in the current of air produced by the fan 4, a device 8 for ducting the air in such manner that the air blown by the fan is directed in roughly horizontal streams in the chamber defined by the muffle 1, and an electric switching device. The latter selectively connects the heating elements and the fan to a power supply. This switching device has a given position in which it is capable of connecting the heating element 6 associated with the fan in series with the upper heating element or elements 11a, 11b while connecting the fan 4 and the lower heating element 14 to the supply.

Abstract: Electrical circuitry for monitoring the current flow through resistance elements on the leading edge of an aircraft wing or horizontal stabilizer. The resistance elements are individually and sequentially activated for heating to thereby effect a de-icing or anti-icing function. The non-activated elements are sensed by the circuitry to determine inferentially if there is a predetermined current flow through the heating elements to achieve the intended de-icing or anti-icing function.

Abstract: An apparatus for controlling energization of quick-heating glow plugs in an internal combustion engine comprises a power supply, a main relay having a normally open contact, a transfer-type changeover terminal having a neutral terminal, a normally closed terminal connected to ground, and a normally open contact connected to the power supply, a plurality of pairs of glow plugs, the glow plugs having one terminals connected through the normally open contact to the power supply, the glow plugs in each pair having one of other terminals grounded and the other terminal connected to the neutral contact, and a control circuit for controlling the main and changeover relays to connect the glow plugs in each pair selectively in series or parallel to each other with respect to the power supply.

Abstract: The bushing temperature measurement device is a microprocessor based sensor which determines the temperature across a multi-segment electrical resistance heated glass fiber producing bushing. The temperature change is determined by calculating the change in resistance of each segment of the bushing by sensing the voltage drop across that segment and dividing by the current flowing in that segment. All measurements of voltage and current are taken simultaneously and averaged over several cycles. The microprocessor, through appropriate output circuitry, alerts other process controls to eliminate any change in temperature.

Abstract: A controller for a water heater having a plurality of individual electrical heating elements changes the number of energized elements to maintain a predetermined minimum temperature. The number of "on" elements is related to the difference between sensed water temperature and a preset water temperature divided by a dead band factor. The heating elements are turned "on" and "off" in a programmed sequence whenever a change is required to optimize the equalization of operating time of the elements. The controller includes a microprocessor which monitors turn "on" or "off" of each element to continuously develop the "on" operational period of each element in relationship to all of the other heating elements since system initialization. The operation period is made relative to the load with the shortest period by substracting the lowest "on" time from all other loads so as to reduce the required memory size.

Abstract: An electronic control circuit for controlling the power applied to an electronic component such as a heater element or an electric winding for a motor. This is effected by measuring variations of the resistance of the component caused by the power flow therethrough. In a preferred form, the circuit has two operational amplifiers, one of which is a voltage comparator and summing amplifier to sum various signals, one being representative of the resistance of the component, the other amplifier operating as a monostable multivibrator. The component, which may be an electric heater for energizing through a switch controlled by the second amplifier. The resistance measurement is effected during the inflection point of the applied AC voltage. The heater is then energized for a full wave of the AC input. During every inflection point the resistance measurement is updated. A modification of the circuit includes a second heater disposed closely adjacent to the object to be heated to serve as an anticipatory circuit.

Abstract: A heating circuit for an electric blanket or the like comprises a heating conductor, a sensor conductor and separating means which separates the conductors and has an impedance that falls with increasing temperature and/or which will melt in the event of overheating to allow contact between the conductors. A thermal fuse and a first diode are connected in series with the heating conductor between AC supply input terminals, and a resistor is thermally coupled to the thermal fuse and electrically connected such that the resistor and the impedance of the separating means are connected in series between the input terminals. A drop in the impedance of the separating means due to overheating will cause the current through the resistor to increase, so heating the resistor to cause the thermal fuse to disconnect the circuit from the supply.

Abstract: In a cooking oven which is cleaned by pyrolyzation of soil within the oven cavity and has a smoke eliminator duct extending through the oven wall, with a smoke eliminator heater disposed adjacent to the duct inlet, a reducing gas sensor is mounted either adjacent to the oven end of the smoke eliminator duct or within the smoke eliminator duct near its discharge end. An electrical relay or microcomputer control is coupled between the gas sensor and the heater to initially heat the oven interior and to later deenergize the heater when the reducing gas sensor output indicates a desired oven condition. The oven heaters are temporarily deenergized when the gas sensor output indicate a smoke eliminator overload. If the gas sensor is mounted in the smoke eliminator duct, the smoke eliminator heater may be deenergized toward the end of the cleaning cycle, so that the effluent is not affected by the smoke eliminator heater before reaching the gas sensor.

Abstract: A protective control arrangement for an apparatus incorporating one or more heating units of the type comprising the concentric assembly of a resistive heating element embedded in an insulating material enclosed within a metallic sheath energized in accordance with a duty cycle power control scheme, which prevents the rupture or separation in the sheath caused by an arc at a discontinuity in the heating element from propagating along a substantial portion of the sheath.In one embodiment, a microprocessor controlled relay associated with each heating element selectively couples and decouples its associated heating element and the power supply. The microprocessor is preprogrammed to control the duty cycle of each heating element by periodically opening the associated relay switch, thereby decoupling the heating element from the power supply for idle periods of predetermined duration. A timer monitors the time between power decouplings.

Abstract: A current controller interface accepts a variable voltage at its input and develops a current at its output which corresponds directly with the input variable voltage. Its apparatus is usually associated with a program controller as an input and a microscope which has a heated element as the output. The apparatus uses a control circuit which is coupled to a controllable resistance semiconductor device, which device has an output which varies in resistance in accordance with variation in input current. The output of the variable resistance device is coupled in series with the heating coil of the microscope, the power supply and current sensing resistor. The resistor develops a feedback voltage which is applied to the control circuit so that when a change in voltage is applied to the input the output from the current sensing element will change until it balances the current being applied at the input. When the balance occurs, no further change in output current will occur.