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4188520 Effective concurrent microwave heating and electrical resistance heating in a countertop microwave oven  
In a cooking oven supplied from a power source of limited capability, a time ratio control system alternately energizes a microwave energy generating system and an electrical resistance heating...
4160153 Duty cycle shared proportional temperature control  
A system having two heaters, such as a photographic processor with a solution heater and a dryer heater, has proportional controllers for each of the heaters. A priority control co-ordinates...
4151401 PTC heating device having selectively variable temperature levels  
A controllable electric heating device uses a PTC resistance body having first areal electrode on one surface and two spaced apart areal electrodes of different areal size on the opposite surface...
4141408 Supplementary heat control for heat pump system  
A supplementary heat control for a heat pump system includes thermostatic sensors on the downstream side of the heat pump heating coil. The sensors upon sensing temperature differentials in the...
4110600 Thermostatically controlled plural heat output portable electric space heater  
A portable electric space heater has a case that surrounds separate electric heating elements, and the case has separated upper and lower airflow openings. A control switch allows manual selection...
4101759 Semiconductor body heater  
A semiconductor body heater is provided with a planar array of radiant heating elements spaced from a reflector. In the preferred embodiment, each radiant heating element comprises a tungsten...
4100428 Control system for limiting the electrical consumption of a distribution network  
The control system permits limiting the electrical demand of a distribution network to a desired maximum value by regulating the temperature of one or more thermal loads with heating or cooling...
4087568 Method and apparatus for controlling a material treater at maximum throughput with air velocity control  
An improved process and apparatus are disclosed wherein the resin treatment of a web on a material treater is conducted at maximum throughput in response to especially impinging air velocity...
4076975 Electrical furnace and parts therefor  
An electrical furnace has a plurality of electrical heaters and a control unit carried by a frame. A rigid lead unit is carried by the frame and has rigid lead means directly and electrically...
4072866 Proportional temperature control system incorporating a linear delay  
A proportional temperature control system using a linear time delay circuit provides an output voltage that is similar to the output voltage of a thermostat but delayed in time. The delay circuit...
4066868 Temperature control method and apparatus  
The disclosed invention describes an apparatus and method for bringing a system having high interactive portions to a predetermined temperature distribution. The invention includes a difference...
4058702 Fluid heating apparatus  
A fluid tank, with an inlet and an outlet, is provided with first heating means for heating the fluid in the tank to a first temperature and a second heating means for heating the fluid to a...
4036457 Aircraft de-icing  
In a method for de-icing aircraft surfaces by means of a plurality of electrical resistance heaters which are sequentially supplied with heating current, the delivery of current to each heater...
4024378 Electric heating system circuit for sequentially energizing a plurality of heating elements  
An electrical circuit for a heating system has a plurality of electrical resistance heating elements and a blower all controlled by a plurality of electro-thermally actuated relays. The circuit is...
4011430 Multizone electrical furnace methods and apparatus  
In a multizone electrical furnace the phase shift effect of the thyristor devices used to control the power supplied to each thermal zone is reduced by providing two or more heater circuits, each...
4010412 Control of electrical power supplies  
Apparatus for distributing power from a single alternating current supply to a plurality of loads having individual switches or thermostats comprises triacs placed in series with each of the...
3982097 Programmable electronic control system for multiple electric stations  
A programmable electronic control system for an array of electrical stations exemplified by food tray stations each of which is adapted to receive a food tray having two or more electrical heaters...
3982092 Electrically heated zoned window systems  
An electrically heated window system having at least two independently heatable zones wherein each zone includes its own independent resistance heating element which provides a path for the flow...
3979060 Automatic multiple unit control apparatus  
Control apparatus for automatically enabling and disabling the thermostatic control of a plurality of building temperature control units. A programmable timer is provided for adapting the control...
3956612 Radiant heating modular unit  
A radiant heating modular array of rapid response radiant heating units includes a plurality of abutting heating element frame units in which the intermediate frame units have open sides and the...
3952182 Instantaneous electric fluid heater  
A miniature electric fluid immersion heater adapted for instantaneously heating relatively small bodies or flow increments of fluid to a predetermined temperature. The heater is particularly...
3943329 Hair dryer with safety guard air outlet nozzle  
A hair dryer includes a housing defining an air inlet and an air outlet and blower means within the housing for drawing a stream of air into the inlet, through the dryer housing and forcing the...
3932729 Multi-stage electric heater apparatus and method of control  
An electric heater control circuit is shown which utilizes a 10-step controller for obtaining eighteen steps of heating control. Electrical and magnetic control circuitry operates this 10-step...
3912906 Circuit for electric heating system  
An electrical circuit for a heating system has a plurality of electrical resistance heating elements which are sequentially operated while a blower is maintained in operation when any of the...
3899782 Apparatus for monitoring reaction end point  
An apparatus for monitoring the course of a reaction under elevated temperature conditions as determined by the temperature of the reaction mixture, and particularly as applied to the processes of...
3892946 Control system for an electrical heating device, and particularly for an electrical sauna stove  
A control system for an electrical heating device and in particular for an electrical sauna stove. The system comprises three heating resistances or groups of heating resistances connected to...
3881091 Control for injection molding  
A control for heating currents in multiple cavity molds in injection molding machines. The principal features include separate modular power controls each having variable resistor means with an...
3855452 KILN HEATING CONTROL SYSTEM  
A control system for an electrically heated ceramic kiln utilizes a plurality of heating coils and a plurality of switching elements connected to the coils so that each coil has more than one...
3855450 LOCOMOTIVE ELECTRIC CAB HEATER AND DEFROSTING UNIT  
A locomotive cab heater including a housing having a fan mounted therein for pumping air over a bank of electric heating panels. A blower may also be provided to give a defrosting action. The...
3846617 BLOWER AND HEATER UNIT  
An integrated heater and blower unit has a housing formed by complementary upper and lower shells of synthetic resin abutting at juxtaposed edges and jointly forming a housing defining a spaced...
3832524 HEATING UNIT FOR COPYING MACHINE  
Circuitry for use in a copying machine capable of copying on copy papers of at least two different widths comprising a voltage source; a heating unit including a central heating element and two...
3818183 ELECTRONIC TEMPERATURE CONTROL SYSTEM  
A Resistance Temperature Detector (RTD) having a predictable positive temperature coefficient produces a D.C. voltage corresponding to the temperature of a medium. A variable resistor that can be...
3812323 ELECTRICAL HEATING BANDS FOR A FEEDING SYSTEM  
Heating bands and cartridge heaters, adapted to be mounted about cylindrical chambers, manifolds and nozzles conveying heated plastic from a feeding system to a molding assembly, are arranged so...
3787729 SEQUENCING STEP CONTROL  
A control for varying loads such as heating elements in response to a change in an environmental variable such as temperature in which the first load to be energized is always the first load to be...
3783240 ELECTRICAL HEATING SYSTEM FOR BODY AND FOOT WARMTH  
A portable electric heating system. This device consists primarily of plug in units having heating elements controllable manually and automatically. The circuit consists of a multiple number of...
3770977 SEQUENTIAL LOADING SYSTEM HAVING AUXILIARY SWITCHES  
A sequential loading control system including a plurality of main switches controlling current flow to respective loads. Respective time delay drive means are provided for controlling the...
3751631 TEMPERATURE CONTROL SYSTEMS  
A heater control system, particularly for temperature unbalance arising in the currents flowing in three heater elements supplied from a three-phase power supply. The current unbalance may be...
3717300 TEMPERATURE CONTROL APPARATUS WITH A CYCLICAL DISTRIBUTOR  
3713062 SNAP DISC THERMAL SEQUENCER  
Apparatus for sequencing the switching of electrical loads comprises a plurality of switch cells built into an electrically insulating housing. Each cell includes a bimetallic disc, motion...
3708650 ELECTRICAL HEATING APPARATUS  
Electrical heating apparatus comprises first and second electric heater means. First means are provided in a control means for deriving from a source of electric power a first derived voltage...
3694625 CONTROL ARRANGEMENT FOR AN AIR HEATING APPARATUS  
An improved control arrangement for an air heating apparatus having a multi-volt electrical power source, a power control circuit for energizing air blower means and air heating means, and a...
3681566 HEATING SYSTEM FOR ASPHALT EQUIPMENT  
A controlled heating system, in which heat-transfer oil, which is circulated through jacketed heating means installed in an asphalt tank, effects the production of a high heat input when oil is...
3668367 ELECTRICALLY HEATED PADS OR BLANKETS  
An electrically heated pad or blanket having two heating elements defining two separate electrical circuits, each circuit being connected to a multi-position switch so that they can be connected...
3659781 MONITORING APPARATUS HAVING AUXILIARY SWITCHING MEANS  
Monitoring apparatus for controlling a circulating means which circulates a fluid in heat exchange relationship with a temperature change unit. Condition sensing means is provided for actuating...
3610886 POWER DIVIDER CIRCUIT FOR TWO-UNIT HOTPLATE  
In preferred form, an electric hotplate with dual resistance-type heating elements which produce a maximum power output at a predetermined current level when operated separately. When operated...
3606970 CONTROL DEVICE FOR A PLURALITY OF STAGES OF ELECTRIC HEAT WITH CURRENT RESPONSIVE MEANS FOR CONTROLLING A FAN  
3588471 SEQUENTIAL LOADING TEMPERATURE CONTROL SYSTEM  
3588444 HAIR-TREATING APPARATUS  
3586869 SEQUENCING CONTROL UNIT  
A sequencing type of control unit means particularly useful for sequencing stages of electric heat in response to a condition-sensing means or thermostat is disclosed. The sequencing type of...
3586822 ELECTRIC BOILER  
A prewired, unit-handled electric water boiler having a boiler casting housing a plurality of immersible heater elements, a removable control panel on which all the circuit elements are mounted...