US3651753A - Electric cooker with automatic current control - Google Patents

Electric cooker with automatic current control Download PDF

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Publication number
US3651753A
US3651753A US73030A US3651753DA US3651753A US 3651753 A US3651753 A US 3651753A US 73030 A US73030 A US 73030A US 3651753D A US3651753D A US 3651753DA US 3651753 A US3651753 A US 3651753A
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United States
Prior art keywords
load
power supply
resistor
source
cycle
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Expired - Lifetime
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US73030A
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English (en)
Inventor
Walter Schmidt
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INTERTRADE WARENVERKEHRSGESELL
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INTERTRADE WARENVERKEHRSGESELL
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/0019—Circuit arrangements
    • H05B3/0023—Circuit arrangements for heating by passing the current directly across the material to be heated
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
    • A47J36/00—Parts, details or accessories of cooking-vessels
    • A47J36/32—Time-controlled igniting mechanisms or alarm devices
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10—Regulating voltage or current
    • G05F1/12—Regulating voltage or current wherein the variable actually regulated by the final control device is ac
    • G05F1/40—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices
    • G05F1/44—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only
    • G05F1/45—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only being controlled rectifiers in series with the load
    • G05F1/452—Regulating voltage or current wherein the variable actually regulated by the final control device is ac using discharge tubes or semiconductor devices as final control devices semiconductor devices only being controlled rectifiers in series with the load with pulse-burst modulation control
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/083—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the ignition at the zero crossing of the voltage or the current
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/0004—Devices wherein the heating current flows through the material to be heated

Definitions

  • ABSTRACT An electric cooker for the direct heating of food by the passage of alternating current therethrough has a two-way electronic valve, triggered at the beginning of each half-cycle of its power supply, connected in series therewith A control voltage derived from a series resistor, varying with the magnitude of the load current, blocks the trigger circuit of the valve during half-cycles of a given polarity whenever the current exceeds a predetermined threshold, the trigger circuit being unswitchable during half-cycles of the opposite polarity so that only complete cycles are suppressed in the case of overload.
  • the rate of heating which determines the necessary cooking time, is a function of the electrical resistance of the goods to be treated and is thus subject to considerable variations.
  • the general object of my present invention is to provide a self-regulating power supply which eliminates these drawbacks and which substantially stabilizes the current flow through a load of unknown resistance, especially a cooker, with protection against overload and automatic compensation for changes in load resistance and/or supply voltage.
  • a more particular object is to provide, in a system in which the presence of direct-current components would be detrimental, means for effectively suppressing such components in controlling the flow of an alternating current.
  • the alternating current supplied by a suitable source such as the usual utility mains (operating at 50 or 60 cycles per second) is passed through the load by way of a normally open electronic circuit breaker in series with the load, this circuit breaker being periodically closable in the rhythm of load current by trigger pulses generated by a network connected to the current source.
  • a current-responsive sensor in the load circuit disables the trigger-pulse generator whenever the load current exceeds a predetennined threshold, thereby maintaining the average current flow substantially constant.
  • a trigger-pulse generator which is unswitchable during half-cycles of a given polarity so that, in the presence of an overload, the interruption and subsequent restoration of the current flow can take place only during half-cycles of the opposite polarity, preferably at the beginning of such half-cycles, whereby only entire cycles are suppressed.
  • the suppression may apply to a single cycle at a time or to several cycles in a row. With proper timing, the average current will remain approximately constant even if the instantaneous load current during individual cycles varies by as much as 100 percent.
  • a convenient way of preserving the same time position for the switching-on and switching-off points of the trigger-pulse generator in different half-cycles, with the further advantage of minimizing transients interfering with radio reception in the vicinity, is to utilize a zero-voltage detector of a type known per se to make the trigger pulses substantially coincide with the crossover of the supply voltage from one polarity to the other.
  • Such detectors are used, for example, in a conventional integrated-circuit module marketed by General Electric under the designation PA424.
  • a component of this nature or its equivalent may be used to trigger a gate-controlled two-way electronic valve of the type known as TRIAC serving as the normally open circuit breaker.
  • Other electronic gates of this description include thyristors or solid-state controlled rectifiers.
  • FIG. 1 is a block diagram of a power supply for an electric cooker in accordance with the invention
  • FIG. 2 is a similar block diagram for a modification of the system of FIG. 1;
  • FIG. 3 is a more detailed circuit diagram of an embodiment similar to that shown in FIG. 2;
  • FIG. 4 is a circuit diagram for another embodiment.
  • the system shown in FIG. 1 comprises a source of alternating current, represented by a pair of terminals A & B, defining between them a load circuit 4 including a cooker l for the direct heating of foods by the current flowing in that circuit, a circuit breaker 2 in series with the load 1 and a sensor 5 for determining the magnitude of this current flow.
  • a branch line 7 terminates at a controller 3 which periodically closes the circuit breaker 2 in the rhythm of the supply voltage either once per cycle or during every half-cycle to energize the load I. In the normal operation, the open period of the circuit breaker 2 may be so short as to result in virtually continuous energization of the load.
  • Sensor 5 works into a processor 6 which acts as a rectifier and storage circuit delivering to the controller 3 a signal voltage to be compared with a predetermined but preferably adjustable reference voltage. If the signal voltage exceeds the threshold thus established, controller 3 is inhibited from closing the circuit breaker 2. With the the load circuit now open, the sensor output disappears so that the overload signal from processor 6 decays at a rate depending upon the storage capacity of this circuit. After one or more cycles, therefore, controller 3 resumes its normal operation of periodically closing and opening the circuit breaker 2.
  • Unit 2' is here shown as a TRIAC, with unit 5' essentially consisting of a low-ohmic resistor in series with the TRIAC and the load 1'.
  • Processor 6' having its input connected across the resistor 5', feeds the controller 3 which, however, is here shown to act upon the circuit breaker not directly but through a trigger circuit 8 associated with TRIAC 2!
  • Circuit 8 normally delivers to TRIAC 2' a series of trigger pulses P which, as more fully described hereinafter with reference to FIG.
  • trigger circuit 8 can be turned on and off by switching signals S in the output 9 of controller 3 only if these trigger pulses occur during half-cycles of a given polarity.
  • trigger circuit 8 is unswitchable; the corresponding trigger pulses are invariably generated if the TRIAC 2' conducts during the immediately preceding half-cycles.
  • the load current traversing the circuit 4' is interrupted only for entire cycles.
  • Trigger circuit 8 may be a module of the type PA424 referred to above and described in detail hereinbelow.
  • FIG. 3 shows a system generally similar to that of FIG. 2, including a load in the form of a cooker 1 connected in series with a TRIAC 10, a trigger circuit 11 of the type PA424, a low-ohmic series resistor 12 forming part of a sensing circuit to determine the magnitude of the load current, a processor 50 receiving the output voltage of sensing resistor 12 by way of a transformer 51, and a control circuit generally designated 60 for switching the trigger circuit 11.
  • Processor 50 comprises a rectifier bridge 14 working into an integrating network 84 which feeds a potentiometer 17 connected between a conductor 102 and a bus bar 107 originating at terminal A.
  • Another bus bar 105 tied to terminal B through the intermediary of a resistor 52, is connected to conductor 102 through a diode 106 so poled that this conductor will be driven negative during negative half-cycles of the supply voltage on terminal B; for purposes of the following discussion, references to positive and negative half-cycles relate to the potential of that terminal relative to terminal A, assumed to be grounded.
  • module 11 The internal structure of module 11, known per se, includes a zero-crossing detector 100 connected between bus bars 105 and 107, a differential amplifier 101 with a blocking lead 13 terminating at the base of one of its transistors, and a Darlington-type output transistor 103 which is normally triggered into conductivity by detector 100 whenever the alternating voltage on bus bars 105 and 107 goes through zero; amplifier 103, when thus conducting, draws gate current via a lead 104 from TRIAC to trigger the same into a conductive condition which persists for the remainder of the half-cycle.
  • a condenser 53 is connected across bus bar 107 and conductor 102 so as to charge during negative half-cycles, this charge being available in the following positive half-cycles to supply the gate current for TRIAC 10 so as to trigger the latter into conductivity.
  • Amplifier 103 can draw this gate current only as long as blocking lead 13 carries negative voltage with reference to conductor 102; when this blocking lead goes positive, the left-hand half of differential amplifier 101 conducts and inhibits the zero-crossing detector 100.
  • Lead 13 is connected to lead 102 through a voltage divider including resistors 61, 62 and 63, the junction of the two latter resistors being tied to the base of an NPN-transistor 21 fortning one stage of a bistable multivibrator or flip-flop whose other stage is a similar transistor 22.
  • the base of transistor 22 - is normally biased positive by a circuit connected across bus bars 105 and 107, this circuit including a collector resistor 64 of transistor 21, a coupling resistor 65, a diode 66 and a condenser 23.
  • junction of this diode and condenser is connected to bus bar 107 through a resistor 67 and, in parallel therewith, through a voltage divider consisting of a pair of resistors 68, 69, the collector of transistor 22 being tied to a common terminal of resistors 61, 62, 68 and 69.
  • Another diode 70 is inserted between conductor 102 and the base of transistor 22 with a polarity blocking the transmission of negative potential from the conductor to that base.
  • a monostable circuit of the Schmitt Trigger type consisting of two transistors 18 (N PN) and 19 (PNP) conditions the flipflop 21, 22 for possible switchover.
  • Transistor 18 has its collector connected via a diode 71 to the collector of transistor 22 and by way of a resistor 72 to the bus bar 107 as well as to the emitter of transistor 19 whose collector is joined to that of an NPN transistor 20 through a resistor 85.
  • a further NPN- transistor 15 has its collector tied through a diode 74 to the base of transistor 19 which is grounded for high frequencies through a condenser 75.
  • Transistor 15 has its base and its col lector connected to the collector of transistor 18 by way of two resistors 76 and 77, respectively, the latter resistor being in series with a further capacitor 16.
  • the base of transistor 15 is also connected to conductor 102 through a resistor 78 forming a voltage divider with resistor 76; the corresponding emitter is connected via a resistor 79 to the variable tap of a potentiometer 17 which is shunted by condenser 53.
  • the two junctions of network 17, 53 are connected to the emitter of transistor 18 through a resistor 80 and a condenser 81, respectivelyfFinally, the base and the emitter of transistor are bridged by a resistor 82, the base being connected through a resistor 83 to live bus bar 105.
  • this transistor charges the condenser 16 at a relatively rapid rate which terminates the unstable condition of the monoflop within a timing interval less than a cycle of the supply voltage (thus, shorter than 20 ms in the case of a 50-c.p.s. power supply).
  • Transistor 20, which in its saturated state blocks the transistor 18, is cut off during negative half-cycles as soon as the voltage of terminal B reaches a certain value, e.g., of 7 V in a specific embodiment. Since the monoflop 18, 19 is switched within less than a cycle after the cutoff of transistor 20, flip-flop 21, 22 will remainclamped during the initial period of the next negative half-cycle, i.e., until transistor 20 is again turned off.
  • the preselected constant current normally drawn by transistor 15 is throttled so that the charging period of condenser 16 is increased beyond the length of a cycle.
  • Flip-flop 21, 22 is now switchable during a short interval between the zero-crossing of the negative-going bus bar and the blocking of transistor 20 a short time thereafter.
  • the rising negative voltage on bus bar 105 biases the transistor 22 into its high-resistance state, thereby stopping the current flow through resistor 69 and driving lead 13 positive, with resulting conduction of transistor 21 and completion of the reversal of the flip-flop.
  • the positive blocking potential on lead 13 inhibits the emission of further gating pulses from trigger circuit 11 to TRIAC 10 until the voltage stored in integrating network 84 has decayed sufficiently to restore the system to normal operation.
  • FIG. 4 shows an alternate embodiment wherein a TRIAC 27 is connected via leads 25, 26 across power supply A, B .in series with a cooker 24 and a sensing resistor 40 substantially in the manner described above.
  • the gate 28 of TRIAC 27 is returned to lead 26 via a pair of series resistors 37, 38 and cascaded diodes 32, 33, the junction of these diodes being tied to lead 25 by way of two other cascaded diodes 34 and 35.
  • a condenser 30 shunts the resistor 37, another condenser 29 being connected in series with a resistor 36 and diode 35 across the load 24.
  • the circuit so far described operates as follows: during negative half-cycles of terminal B (terminal A being again considered grounded), a firing current flows through gate 28 by way of resistors 37 and 38 as well as diodes 33 and 32. With the TRIAC conducting, condenser 29 is charged through diode 35 and resistor 36 so that, at the beginning of the following positive half-cycle (with the potential difference between terminals A and B approximately zero), the discharge of this condenser triggers another gating pulse through diodes 34 and 32. Thus, the TRIAC 27 conducts substantially continuously, firing with every half-cycle.
  • a gate-controlled rectifier 39 or thyristor is connected between the junction of resistor 38 with diode 33 and the common terminal of load 24 and resistor 40.
  • the gate 41 of this thyristor is returned to its cathode through a resistor 44 shunted by a variable portion of a potentiometer 46, the latter being in parallel with a condenser 43.
  • This condenser is connected across resistor 40 in series with a further resistor 45, a diode 42 and part of an autotransformer 48; the latter may also be adjustable to vary the effective magnitude of the monitoring voltage applied to the processing stage 42, 43, 45 by sensing resistor 40.
  • a shunt condenser 47 serves (as also in the system of FIG. 3) to short out transients and to help suppress radio-frequency noise. Since, however, the TRIAC 27 fires only during zero crossings, transients due to the aforedescribed switching operations will be minimized even without such additional protection. Naturally, the usual safety requirements (e.g., fusing) will have to be observed.
  • a current exceeding this level may result in the suppression of a sufficient number of cycles to keep the mean power consumption approximately constant, e.g., one cycle in four with currents of 9 amps., every other cycle with 12 amps, and five cycles in six with 16 amps.
  • a self-regulating power supply for a load driven by alternating current comprising:
  • valve means in said circuit in series with the load, said valve means being provided with gating means enabling same to be triggered into a state of conductivity terminating upon a polarity reversal of said source;
  • control circuit connected between said source and said gating means for generating a train of trigger pulses normally establishing said state of conductivity at the beginning of the first half of each cycle of said source, said control circuit including capacitive means chargeable during said first half for energizing said gating means during the immediately following second half of a cycle;
  • switch means in said control circuit responsive to said sensing means for suppressing said trigger pulses upon said average magnitude exceeding a predetermined threshold, thereby inhibiting initiation of conductivity of said valve means for at least one full cycle of said source, said capacitive means being effective independently of said switch means to establish such conductivity in the second half of a cycle upon conduction of said valve means in the first half thereof.
  • a power supply as defined in claim 1 wherein said switch means comprises a transistor with an input circuit connected to said sensing means and with an output circuit including said capacitive means.
  • sensing means comprises a resistor in series with the load, said input circuit being connected across said resistor.
  • variable impedance means comprises a potentiometer connected to supply a reference voltage in bucking relationship with the output of said diode means.
  • variable impedance means comprises an autotransformer inserted between said resistor anfl sa id d iodf m eans.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Food Science & Technology (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Electrical Variables (AREA)
  • Cookers (AREA)
  • Control Of Resistance Heating (AREA)
US73030A 1969-09-17 1970-09-17 Electric cooker with automatic current control Expired - Lifetime US3651753A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT882469A AT292141B (de) 1969-09-17 1969-09-17 Kochgerät für Speisen
AT539470A AT305455B (de) 1969-09-17 1970-06-15 Kochgerät für Speisen

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US3651753A true US3651753A (en) 1972-03-28

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US73030A Expired - Lifetime US3651753A (en) 1969-09-17 1970-09-17 Electric cooker with automatic current control

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US (1) US3651753A (de)
JP (1) JPS5015425B1 (de)
AT (2) AT292141B (de)
AU (1) AU2005370A (de)
BE (1) BE756260A (de)
CH (1) CH528890A (de)
DE (1) DE2043688A1 (de)
FR (1) FR2061483A5 (de)
GB (1) GB1295745A (de)
NL (1) NL7013329A (de)
SE (1) SE353004B (de)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3749884A (en) * 1971-12-17 1973-07-31 Kalle Ag Semi-conductor alternating current regulating means
US3996385A (en) * 1970-08-24 1976-12-07 Electro-Food Ab Method and device for preparing foodstuffs with direct passage of electric current
US4029937A (en) * 1974-10-04 1977-06-14 Russell Robert G Control system for electrically conductive liquid heating apparatus
US4086466A (en) * 1976-04-30 1978-04-25 Scharlack Ronald S Automatic heater controller
US4377739A (en) * 1978-01-16 1983-03-22 Pitney Bowes Inc. Average power control apparatus and method
US4400613A (en) * 1978-12-04 1983-08-23 General Electric Company Temperature controller for a fusing roller
US4554440A (en) * 1981-08-07 1985-11-19 Lee Jr Maurice W Automatic circuit control for electrical resistance cooking apparatus
EP0212012A1 (de) * 1985-08-05 1987-03-04 Maurice W. Lee Jr. Regelung für ein elektrisches Widerstandskochgerät
US4705936A (en) * 1985-01-17 1987-11-10 Masco Corporation Electronically controlled electric steam humidifier
AU568221B2 (en) * 1981-08-07 1987-12-17 Lee, M.W. Control circuit for resistance cooking
US4822982A (en) * 1987-09-08 1989-04-18 Lee Jr Maurice W Automatic circuit control for electrical resistance cooking apparatus
DE3736659C1 (de) * 1987-10-29 1989-05-24 Telefunken Electronic Gmbh Temperaturregelschaltung
US5290583A (en) * 1992-04-02 1994-03-01 David Reznik Method of electroheating liquid egg and product thereof
US5662025A (en) * 1995-08-21 1997-09-02 Samsung Electronics Co., Ltd. Control circuit for an electric cooker
US5670199A (en) * 1992-04-03 1997-09-23 North Carolina State University Method for pasteurizing liquid whole egg products
US5761988A (en) * 1994-10-17 1998-06-09 Samsung Electronics Co., Ltd. Apparatus for controlling a rice cooker to evenly distribute rice therein
US5928546A (en) * 1997-08-29 1999-07-27 Maurice W. Lee, Jr. Electrical resistance cooker and automatic circuit controller
US20160037582A1 (en) * 2013-03-14 2016-02-04 Weiss Controls Inc. Bi-polar triac short detection and safety circuit
CN107567122A (zh) * 2016-07-01 2018-01-09 佛山市顺德区美的电热电器制造有限公司 电磁加热烹饪系统及其加热控制装置和控制方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2642794A (en) * 1949-03-02 1953-06-23 Spiess Irwin Electric frankfurter cooker
US3197691A (en) * 1962-01-02 1965-07-27 Gen Electric Regulated power supply
US3319152A (en) * 1963-12-19 1967-05-09 Honeywell Inc Scr switching circuit
US3356784A (en) * 1964-03-03 1967-12-05 Lucas Industries Ltd Apparatus for varying an alternating current flowing in a load to control the value of a parameter such as the temperature of a furnace
US3486042A (en) * 1965-05-18 1969-12-23 Gen Electric Zero crossing synchronous switching circuits for power semiconductors supplying non-unity power factor loads
US3514580A (en) * 1968-07-12 1970-05-26 Honeywell Inc Burst firing control apparatus with soft start

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2642794A (en) * 1949-03-02 1953-06-23 Spiess Irwin Electric frankfurter cooker
US3197691A (en) * 1962-01-02 1965-07-27 Gen Electric Regulated power supply
US3319152A (en) * 1963-12-19 1967-05-09 Honeywell Inc Scr switching circuit
US3356784A (en) * 1964-03-03 1967-12-05 Lucas Industries Ltd Apparatus for varying an alternating current flowing in a load to control the value of a parameter such as the temperature of a furnace
US3486042A (en) * 1965-05-18 1969-12-23 Gen Electric Zero crossing synchronous switching circuits for power semiconductors supplying non-unity power factor loads
US3514580A (en) * 1968-07-12 1970-05-26 Honeywell Inc Burst firing control apparatus with soft start

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996385A (en) * 1970-08-24 1976-12-07 Electro-Food Ab Method and device for preparing foodstuffs with direct passage of electric current
US3749884A (en) * 1971-12-17 1973-07-31 Kalle Ag Semi-conductor alternating current regulating means
US4029937A (en) * 1974-10-04 1977-06-14 Russell Robert G Control system for electrically conductive liquid heating apparatus
US4086466A (en) * 1976-04-30 1978-04-25 Scharlack Ronald S Automatic heater controller
US4377739A (en) * 1978-01-16 1983-03-22 Pitney Bowes Inc. Average power control apparatus and method
US4400613A (en) * 1978-12-04 1983-08-23 General Electric Company Temperature controller for a fusing roller
US4554440A (en) * 1981-08-07 1985-11-19 Lee Jr Maurice W Automatic circuit control for electrical resistance cooking apparatus
AU568221B2 (en) * 1981-08-07 1987-12-17 Lee, M.W. Control circuit for resistance cooking
US4705936A (en) * 1985-01-17 1987-11-10 Masco Corporation Electronically controlled electric steam humidifier
EP0212012A1 (de) * 1985-08-05 1987-03-04 Maurice W. Lee Jr. Regelung für ein elektrisches Widerstandskochgerät
US4822982A (en) * 1987-09-08 1989-04-18 Lee Jr Maurice W Automatic circuit control for electrical resistance cooking apparatus
DE3736659C1 (de) * 1987-10-29 1989-05-24 Telefunken Electronic Gmbh Temperaturregelschaltung
US5290583A (en) * 1992-04-02 1994-03-01 David Reznik Method of electroheating liquid egg and product thereof
US5415882A (en) * 1992-04-02 1995-05-16 Knipper; Aloysius J. Producing extended refrigerated shelf life food without high temperature heating
US5533441A (en) * 1992-04-02 1996-07-09 Reznik; David Apparatus for rapidly cooling liquid egg
US5670199A (en) * 1992-04-03 1997-09-23 North Carolina State University Method for pasteurizing liquid whole egg products
US5761988A (en) * 1994-10-17 1998-06-09 Samsung Electronics Co., Ltd. Apparatus for controlling a rice cooker to evenly distribute rice therein
US5662025A (en) * 1995-08-21 1997-09-02 Samsung Electronics Co., Ltd. Control circuit for an electric cooker
US5928546A (en) * 1997-08-29 1999-07-27 Maurice W. Lee, Jr. Electrical resistance cooker and automatic circuit controller
US20160037582A1 (en) * 2013-03-14 2016-02-04 Weiss Controls Inc. Bi-polar triac short detection and safety circuit
US10536991B2 (en) * 2013-03-14 2020-01-14 Multitech Medical Devices Usa Llc Bi-polar triac short detection and safety circuit
CN107567122A (zh) * 2016-07-01 2018-01-09 佛山市顺德区美的电热电器制造有限公司 电磁加热烹饪系统及其加热控制装置和控制方法
CN107567122B (zh) * 2016-07-01 2020-12-22 佛山市顺德区美的电热电器制造有限公司 电磁加热烹饪系统及其加热控制装置和控制方法

Also Published As

Publication number Publication date
JPS5015425B1 (de) 1975-06-05
NL7013329A (de) 1971-03-19
SE353004B (de) 1973-01-15
DE2043688A1 (de) 1971-04-29
AU2005370A (en) 1972-03-23
AT305455B (de) 1973-02-26
FR2061483A5 (de) 1971-06-18
BE756260A (fr) 1971-03-01
CH528890A (de) 1972-10-15
AT292141B (de) 1971-08-10
GB1295745A (de) 1972-11-08

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