Abstract: A burner for a heat supplying device includes a substrate of thermally insulating material, the substrate defining a plurality of openings therethrough for flow of an air/gas mixture therethrough from a first side of the substrate to a second side of the substrate for combustion adjacent to the second side of the substrate. The burner further includes a high temperature metal wire disposed on the second side of the substrate and projecting outwardly therefrom, and a cover layer of heat transmissive material overlying the metal wire to provide a support surface on the heat-supplying device for supporting a heat-consuming item.

Abstract: A microwave radiation source is introduced into a fry basket within the fry tank of a deep fat fryer to reduce the cooking time of food products within the fry basket. Microwave energy is generated outside the fry tank and coupled into the fry basket by a microwave tuned transition, waveguide and antenna. Microwave chokes seal the basket top cover and microwave antenna to basket interface to confine the microwave energy to the fry basket. An electrical safety interlock prevents generation of microwave energy unless the fry basket is sealed.

Abstract: A microwave radiation source is introduced into a fry basket within the fry tank of a deep fat fryer to reduce the cooking time of food products within the fry basket. Microwave energy is generated outside the fry tank and coupled into the fry basket by a microwave tuned transition, waveguide and antenna. Microwave chokes seal the basket top cover and microwave antenna to basket interface to confine the microwave energy to the fry basket. An electrical safety interlock prevents generation of microwave energy unless the fry basket is sealed.

Abstract: An apparatus for cooking an article is provided including a cooking chamber, a heating means for producing heated gases for introduction into said chamber for convective heating without microwave interference, and a source of microwaves for heating with microwave energy. At least one freely rotating stirring means is positioned in gas and microwave communication with the heating chamber, and is caused to rotate from a flow of the heated gases. The stirring means serves to distribute both microwave energy and the heated gases about the chamber for uniform, simultaneous convection and microwave heating. A pilotless gas source is provided which includes an initiation chamber within a combustion chamber. The initiation chamber is positioned by a microwave opaque material and includes a flame sensor which eliminates the flow of gas in the combustion chamber when no flame is present.

Abstract: Disclosed is a gas-fired oven for heating food by steam and/or dry convection. The oven has a heating chamber; an atomizer for producing an atomized water spray; a source of a combustible gas mixture; and a burner-heat exchanger. The gas fired burner-heat exchanger receives and combusts the mixture and isolates hot combustion gases from the heating chamber so pure steam is furnished to the heating chamber. The heat exchanger receives hot combustion gases, and vaporizes atomized spray circulated over its external surface to produce steam for heating an article in the heating chamber. The amount of steam in the heating chamber is measured and controlled by monitoring a temperature in a drain.

Abstract: A gas/air mixing valve is provided for regulating the amounts of combustion air and fuel gas that are delivered to a burner or a series of burners for use with both residential and commerical cooking ranges. The mixing valve overcomes the problem of pressure disturbances caused by known mixing valves by drawing a constant flow of combustion air regardless of whether the burner to which it is supplying fuel gas and air is off or operating at any intensity level. In a preferred embodiment the mixing valve is provided with an adjustable orifice disk which directs a constant flow or air, in selectable proportions, to either combine in the mixing valve with fuel gas for combustion or bleed to atmosphere. By always drawing a constant flow of air independently of the operating level of the burner, the mixing valve allows adjustment of individual burners with no effect on other burners connected to the system.

Abstract: Infrared (IR) strip heaters are juxtaposed with convection heaters for simultaneous, independently controlled, combined radiant/convective heating in a conveyor oven. Apertured plates with portions transmissive to IR radiation are interposed between a lower combined heating unit and the cooking path. The IR heaters are preferably gas burners with porous, ceramic or metallic elements, the burners on opposite sides of the cooking path being independently controllable to vary the heat transfer rate to opposite food surfaces. Symmetrical placement of the IR heaters in opposed pairs facilitates use of the conveyor oven as a half oven. An auxiliary burner exhausts directly into the convection air and is cycled on and off to maintain a set temperature during normal operation.

Abstract: A liquid-fueled thermoelectric field burner operable in two modes, a start-up mode and a steady-state mode. A rechargeable battery backed up by a manually operated generator permits cold start-up of a preheat burner followed by operation of a main burner which provides heat to thermoelectric converters which operate to provide necessary power for steady-state operation. Cold start-up is facilitated by atomizing the liquid fuel for combustion in the preheat burner, and steady-state blue flame operation is enhanced by mixing vaporized fuel and preheated air for combustion in a main burner. The thermoelectric converters are cooled by air from a cooling blower.

Abstract: An efficient, low cost, gas-fired convection oven is disclosed. The oven includes a burner, such as a ceramic induced draft/boosted burner with premixed pressurized air/fuel gas supply, which fires combustion products through an opening in a baffle directly into a convection blower. The blower assembly, protected by a shield/deflector structure, also draws gases from a cooking chamber around the burner to mix with combustion products in a blower chamber. Action of the blower directs the mixture through the blower to circulate through gaps formed by the top and bottom of the baffle and into the cooking chamber. The oven avoids complex, costly wall-type heat exchangers, has no combustion chamber, and provides efficient, uniform cooking in a unit of low manufacturing cost.

Abstract: Disclosed is a high efficiency deep fat fryer from whose fry tank fat is continuously withdrawn for heating and filtration. A pump circulates part of this fat through a helical- or serpentine-shaped finned-tube heat exchanger positioned between a gas-fired burner and the bottom of the fry tank. The remaining portion of fat is directed through a filter located in the bottom zone of the fry tank. The fryer includes a control system with sensors such as pressure switches for preventing damage to the fat at low flow rates and devices for expelling moisture trapped in the pump. The filter has an element of material such as carbon-impregnated cloth which may be quickly replaced without draining fat from the tank.

Abstract: A measuring circuit for obtaining a mean square value of a power distribution line paramter and a process for obtaining a mean square value is disclosed. The measuring circuit and process exploit my discovery that an accurate measurement of the mean square may be closely approximated by sampling the power parameter an odd number of times greater than one during the power parameter cycle. When the power parameter is sampled an odd number of times (N) during its cycle aliasing errors due to the existence of odd harmonics above the Nyquist Frequency are minimized. As a result, the means of the most recent N sample values squared is very nearly equal to the true mean square value which would be produced by a continuous integration of the square of the power parameter during its period divided by the period. By sampling at a relatively low frequency, errors and circuit complexity are reduced, and the speed with which an acceptable mean square value is obtained is increased.

Abstract: A current measuring apparatus utilizes a known fundamental frequency, e.g., 60 Hz, for measuring current and includes a sensing and measurement pulse generation circuit including a current transformer for developing a low power signal directly related to the line current in a powerline, and a diode bridge with a first Zener diode for sensing when the developed current related signal exceeds a first predetermined positive threshold value and a second Zener diode for sensing when the developed current related signal falls below a second predetermined negative threshold value. Across the bridge is an LED for generating a first measurement signal having a duration related to the time when the developed signal exceeds the positive threshold value and second measurement signal during the time when the current related signal falls below the negative threshold value.

Abstract: The method of the present invention encompasses comparing the instantaneous value of a waveform with at least two reference voltages, -R and +R, when crossing of these voltages occurs and processing this data in a data processor (46) to determine parameters of the waveform such as frequency and amplitude and of fundamental and DC offset.The apparatus of the present invention includes comparators (E.sub.1 and E.sub.2) which senses the voltage crossings and which has outputs (28 and 30) inputted to a latch (36) and to logic circuitry (32). A counter (50) supplies a count to the latch (36) and the output of the latch (36) is coupled to a microprocessor (46). The logic circuitry (32) has an output (34) coupled to the latch and to the microprocessor (46) first for causing, when a crossing occurs, the latch (36) to latch data identifying the particular crossing made and a count of the time it occurred and second to cause the microprocessor (46) to input this latched data and then to reset the logic circuitry.

Abstract: A gas-fired cooking range having a powered combustion air and gas input; proportional turndown burner control irrespective of the number of burners being used or the degree of turndown of any burner; light-weight jet impingement/radiation members being provided on each burner for efficient heat transfer to utensils and a simplified ignitor/sensor system for all burners operable by any individual burner control.

Abstract: Disclosed is a gas-fired cooktop for a range which provides high thermal efficiency and low emissions of air pollutants, particularly low levels of NO.sub.x. The cooktop includes a perforated tile burner which radiates infrared energy upward at a high flux rate to rapidly quench burner gas temperatures and inhibit the formation of NO.sub.x. A perforated glass-ceramic jet plate positioned between the burner and a cooking vessel transmits most of the radiant infrared energy from the burner to the vessel and also forms jets of combustion products which are directed against the bottom of the vessel for convective heating. Thermal efficiencies of up to about 70 percent and NO.sub.x emissions as low as about 15 parts per million are achieved by the cooktop.

Abstract: A compact steam cooking unit includes a compartment for holding fresh or frozen food to be cooked by steam and an associated gas-fired generator of steam which are combined in a fully self-contained appliance which requires only conventional utility connections and can be mounted on a counter-top. The steam generator includes a powered burner firing into one or more fire tubes which are submerged in water which is maintained at a desired level in a water chamber. Steam derived from heating of the water passes from the water chamber through ports into the cooking compartment where it contacts the food to be cooked.

Abstract: A microprocessor based recloser control has a microcomputer for causing trip and close operations of a recloser in response to the conditions of the power distribution lines being protected and operator commands. The microcomputer may be overridden by a mechanical switch in the recloser control. If power to the recloser control is lost, the microprocessor will continue to function with power storage means for a limited duration. Towards the end of that duration, this microcomputer will power down the microprocessor in an orderly manner allowing automatic return to its functions when power is restored. After the microprocessor is no longer functioning, a secondary overcurrent trip circuit is relied upon to cause a trip operation of the recloser for extended durations of power outage. The secondary overcurrent trip circuit can be disabled by the microprocessor.

Abstract: The power theft detector circuit (10, 110 and 210) detects when current is being diverted around a line conductor (20 or 220) passing through a meter housing (14 or 214). The circuit (10, 110 or 210) includes a current transformer (12, 112 or 212) coupled to the line conductor (20 or 220) within the meter and defines a primary winding (20 or 220) of the current transformer (12, 112 or 212). A secondary circuit (23, 123 or 224) includes a secondary winding (22, 122 or 226) of the transformer (12, 112 or 212) and sensing circuitry (24, R.sub.m, R.sub.1, and S; 124, R.sub.m, R.sub.1, S and 126; 232, R.sub.m, and 240) for sensing a change in the impedance reflected from the primary circuit into the secondary circuit (23, 123 or 224) when a low impedance jumper (26, 260) is connected in parallel with the line conductor (20 or 220) in the meter thereby to sense a power theft condition.

Abstract: A broiler for cooking food products has an upper heating unit located in a spaced relationship from the food and a lower heating unit in a close heat transfer relationship with the food. The upper unit is preferably a U-shaped radiant fire tube with a gas-fired power burner mounted at one end as a heat source. Hot flue products exiting the radiant tube are directed to the lower heating unit which is preferably a heat pipe assembly with evaporator and condenser zones for a working fluid. In one form the condenser zone includes a generally flat wall portion with a cooking surface defining a set of upwardly facing grooves. In another form the condenser zone is a series of generally parallel pipes that extend under the food in a horizontal, mutually spaced relationship. A movable rack supports the food and moves it into and out of a cooking relationship with the condenser zone of the heat pipe assembly.

Abstract: The electronic watt-hour meter (10) comprises an electro-optical watt-hour sensor (12) adapted to be coupled to a consumer's connection to a source of electric power for sensing voltage supplied to, and the current drawn by, the consumer's electric load and for producing output signals indicative of a quantity of watt-hours of power utilized by the consumer. In the meter (10) a microprocessor (22) is coupled to the sensor (12) for receiving output signals therefrom and a memory (29) is coupled to the microprocessor (22) for receiving and storing data. A power supply (24) supplies D.C. power to the microprocessor (22) and includes a clock signal generator to supply a 60 Hz. clock signal to the microprocessor (22). Also a visual display (30) is coupled to the microprocessor (22) for providing a readout of the power consumed since the last reading of the solid state watt-hour meter.