Abstract: A stove including circuitry to facilitate avoidance of fires such as may be caused by grease or another flammable substance present on the stove burner. The circuitry detects when such burner has been set above a predetermined temperature or power level for a selected duration and responsively disengages same. In presently preferred embodiments, the circuitry includes an indicator circuit operative to produce an output when the predetermined temperature or power level has been exceeded. This output initiates operation of a timer circuit which will itself produce an output after the selected duration. An appropriate switching circuit is provided to then disengage the burner as desired.

Abstract: The present invention relates to a method and device each for controlling the temperature of a thermal fixing machine where a toner image is fixed on a recording medium in a printer, a facsimile apparatus, or a copying machine using electrophotograpic technique. The object is to control the temperature, of a thermal fixing machine with high accuracy by increasing substantially a resolution of an A/D converter without increasing a device manufacturing cost, and reducing an effect on a temperature detection value due to noises. The system includes temperature detecting device for detecting the temperature of a thermal fixing machine as a digital value, sampling device for sampling plural temperature detection values detected with said temperature detecting device, and control device for subjecting a heater to an on/off control based on plural temperature detection values sampled by the sampling device.

Abstract: Invention discloses a heated die to form long lived aperatures in upper region of plastic wrapped packages; said die featuring improved construction providing focused unidirectional heat flow to avoid package failure leading to product deterioration and package failure and disengagement with display hangers; said heat control effected by micro control of flow of energizing electricity.

Abstract: Cooking system comprising a cooking area (1) with actuators (2) which are adjustable to change relevant parameters determining the cooking process of a food. A television camera (3) monitors the cooking area (1) and drives a processor (5) with information relating to the operative conditions in the cooking area (1) . The processor (5) is associated with a memory device (7) storing typical cooking programs consisting each of a different combination of process parameters. The processor (5) is responsive to the incoming data to select the most suitable among the stored cooking programs, whereby it compares the parameters thereof with the corresponding information from the camera (3) to control the actuators (2) with respective error signals. The cooking process is regulated in a fully automatic manner, based on the actual conditions of the food being cooked.

Abstract: A crystal, which is mounted in a rotatable support for use in tuning the wavelength of an optical parametric oscillator, is maintained at a desired temperature by positioning a heating sleeve to thermally coupled to the crystal and its support in such a way that the crystal is still free to rotate. The heating sleeve has an embedded heating element for connecting to an electronic controller whose dynamic output response matches the dynamic temperature characteristics of the combination of components including the crystal, it rotatable holder and the heating sleeve, so as to quickly stabilize changes in the crystal temperature with a minimum amount of overshoot.

Abstract: To provide a balanced supply of distilled water and undistilled hot water for a household, a condenser coil communicates at one end with a steam generator located above a hot water heater and at its other end well the holding tank of a distilled water system, with a condenser entering the hot water heater near the bottom. The steam generator power input matches the power needed to meet the recovery rate to satisfy undistilled hot water demand under normal conditions. The condenser includes a plurality of loops grouped together so a line drawn from top to bottom through them is no longer than 5 inches. The length of the loops is at least 6 inches and the tubes have inside diameters between 1/4 inch and 5 inches and a total area of at least 25 square inches. Near the outlet of the condenser, the tube bends upwardly by approximately a diameter to create a water holding portion in the lower most loop of the condenser to restrain condensate and maximize heat transfer.

Abstract: There is provided an abnormal temperature detection device for a regeneration resistor for consuming the regenerative energy of an electric motor, which includes a heat conductive member (11) disposed in contact with the surface of a regeneration resistor (1), and a thermostat for detecting a rise in the temperature due to an abnormal heat generated in the regeneration resistor (1), via the thermostat (12). The thermostat (12) the regeneration resistor (1) are disposed in different spaces. The thermostat (12) is mounted on a portion at which the temperature is lowered, via the heat conductive member (11), and the temperature of that portion is detected instead of directly detecting the surface temperature of the regeneration resistor (1) which is set at high temperatures. Accordingly, a high temperature state of the regeneration resistor (1) can be detected by using a thermostat able to detect a low temperature.

Abstract: A method and an apparatus for controlling a fixing device in an electrophotographic recording system provides for periodically sampling the temperature of the fixing device, detecting whether the sampled temperature of the fixing device is on an upward trend of a downward trend, and controlling the on/off operation of the fixing device on the basis of the detected trend and on a predetermined changeover temperature range.

Abstract: A temperature control system for use with a fluid circulating system operable in a heating or cooling state to monitor and control the temperature and flow of fluid circulated through a remote liquid circulation manifold comprising a display/control panel to select the system operating parameters and provide a visual indication of the system status including operating temperature and fluid flow and a micro control including logic circuitry to receive input signals from the display/control panel and fluid circulating system and to generate system control signals to control the operation of the fluid circulating system and system indicator signals to provide the visual indication of system operations.

Abstract: An improved temperature control fluid circulating system for automatically cooling a temperature control fluid in a thermal blanket with a thermoelectric cooling device having a cold side and a hot side when powered by electricity wherein the temperature control fluid is cooled by the cold side of the cooling device and pumped to, through, and from the blanket through first and second conduits. The system includes a device for powering the cooling device with pulse width modulated electrical signals; a device for sensing the temperature of fluid flowing within each of the conduits; a device coupled to the sensing device for calculating from the sensed temperatures an indication of the temperature of the fluid flowing within the blanket; and a device associated with the powering device for modifiying the temperature of the fluid by controlling the pulse width modulation of the power supplied to the thermoelectric cooling device.

Abstract: A cooking heating apparatus has a vapor sensor for sensing the state of heating of food in a heating chamber, thus performing automatic control of the heating operation. An auxiliary exhaust opening for allowing vapor from the heated food to be introduced to the vapor sensor is formed in a region where the flow of the vapor is not influenced by a main flow of air supplied into the heating chamber and flowing towards a main exhaust opening. The vapor sensor is disposed so as to be exposed to the vapor introduced through the auxiliary exhaust opening. The condition of the vapor is therefore sensed quickly without being influenced by the main flow of air.

Abstract: A quick heatng burner for burning fuel is disposed in the intake pipe of a gasoline engine or a diesel engine, and a heat exchanger is positioned downstream of the burner. Heat generated by the heat exchanger is utilized to heat the interior of the passenger compartment of a motor vehicle. Operation of the burner and the heat exchanger is monitored by an electronic controller, which generates an alarm and stops the burner and the heat exchanger when they fail.

Abstract: An electric range having a self-cleaning oven utilizes a digital electronic microprocessor based oven temperature control system having multiple, redundant oven temperature sensing elements. The output signal from a first one of the multiple oven temperature sensing elements disposed in the cavity of the oven is used as a primary sensed bake temperature signal for controlling the temperature of the oven during its BAKE mode of operation and as a redundant or back-up sensed clean temperature signal for safely shutting down the oven during its CLEAN mode of operation in the event that the sensed oven temperature significantly exceeds the top of the clean temperature range.

Abstract: A system for circulating hot or cold liquid through a pad placed in thermal contact with a patient for thermal therapy. The system includes a flexible thermal pad with an internal channel for carrying the liquid and a pump assembly for circulating and optionally heating the liquid. The patient-contacting surface of the pad comprises a foam having a cushioned surface to reduce the risk of ischemia and enhance patient comfort. An open-cell foam structure absorbs and retains moisture for applying moist heat. The system is microprocessor controlled and includes a heater to warm the liquid to a selectable temperature for heat therapy. A display selectively indicates set-point or actual liquid temperature in either .degree. F. or .degree. C. as desired. Safety features include three separate over-temperature sensors, a tilt switch and a float switch which de-energize both the heater and the pump when an abnormal temperature is sensed, the unit is tipped or a low liquid level is sensed, respectively.

Abstract: In an instrument used to measure x-rays of the kind in which a wire anode operates in a gaseous atmosphere in a sealed housing to detect x-rays, the instrument is rejuvenated by passing a heating current through the anode to raise its temperature for a period of between two and six hours to convert any impurities to a compound.

Abstract: A heating control apparatus for exciting the heating element of a kiln or the like. The heating control apparatus includes an interval timer that produces a pulse of electricity having a predetermined duration of time, a fixed timer adapted to open and close an electrical path, and a power relay connected to the heating element and which is adapted to excite the heating element for selected periods of time in response to the operation of the fixed and interval timers.

Abstract: An apparatus for controlling and adjusting heat output during the heating phase of a cooking vessel. The cooking vessel is heated by an electric heating element and the temperature inside the cooking vessel is measured. The heating element is provided with a control circuit and two program memories which operate as a function of the temperature increase characteristics during the simmer or warming cycles, whereby in the simmer cycle, both the first and second program memories are operative whereas in the warming cycle only the second program memory is operative in a similar manner as during the simmer cycle and over the same temperature differential but at different temperature values.

Abstract: The invention relates to a situation in which a merchant puts at a client's disposal an apparatus (9) for processing consumer articles (1) that are sold by him. The operation of the apparatus (9) is made dependent on the purchase of the consumer article (1) in question by making an element (4) releasing the operation of the apparatus (9) to form part of the packing (2) so as to make operation of the apparatus (9) only possible with the unlocking element (4).The unlocking element can take the form of a cardboard card (4) on which a magnetic strip (5) containing a code is applied. The apparatus may be a coffee making apparatus (9) comprising a device for reading the magnetic code of the card (4), releasing the coffee making process and for extinguishing the code.

Abstract: A heating wire embedded in any one of several types of shaped elements is fed current by an electrical control apparatus for a time interval which is a function of the ohmic resistance of the wire and the type of shaped element. The type and resistance are automatically determined in advance by measurement of the wire impedance which indicates type and of the ohmic resistance. Welding time is selected from a predetermined directrix depending on resistance, and the directrix itself is chosen on the basis of type by the impedance measurement. A count representative of the time is stored in a counter and pulsed down to zero while current is delivered.

Abstract: An inductance sensor is intended for determining or controlling the gap between a sealing strip and sector plate in a rotary regenerative air preheater of the rotating-matrix type, the strip being on the matrix and being swept past the non-rotating plate. The sensor has a U-shaped core the legs of which lie in a plane generally corresponding to that containing the sealing strip when nearest to the sensor. The legs have unequal coils on them. Energization of the coils allows information to be derived concerning the gap between the strip and plate which may be recorded, displayed, or directly used to adjust that gap to a desired value by movement of the sector plate.

Abstract: A method and apparatus for controlling the temperature of a heater element in accordance with the dwell time of an item to be heated by the heater element. The apparatus of the invention utilizes a temperature tracking circuit which is energized by a low voltage DC power source and a switching system for operating the tracking circuit in either an automatic or standby mode. Sensors are provided for determining the dwell time of an article to be heated by the heater element and a thermocouple or the like is provided for sensing the temperature of the heater element. A heat controller, preferably of the digital programmable variety, is connected to the heater element and is responsive to the dwell time and the thermocouple for controlling the power to the heater in accordance with the dwell time and instantaneous heater temperature whenever the equipment associated with the heater element is operating in the automatic mode.

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: Heating apparatus particularly for flameless atomization in spectrophotometers includes a variable electrical power source and a resistive heating element. A desired final temperature and the rate of change of the element temperature (ramp rate) is input to a control circuit. A storage means is provided for storing data relating the heating element temperature to the energy input (voltage) to the heating element required to maintain the heating element at a constant temperature. Processing means calculates from the various data the voltage required to be supplied to the element by the power source to change the temperature thereof at the selected ramp rate until it reaches the final temperature. In spectrophotometers the apparatus accurately controls the carbon rod temperature through drying, ashing and atomizing stages.

Abstract: A heat cooking apparatus with a temperature operating system, wherein a microcomputer detects an abnormality of a temperature sensor and de-energizes the cooking apparatus to stop cooking while also producing a sensor fault pulse signal. Upon counting of a predetermined number of sensor fault pulse signals in a counter, the microcomputer generates a sensor defect signal to alert the user of the defective temperature sensor. Spurious fault conditions are ignored by resetting the counter upon proper operation of the sensor before reaching the predetermined number of sensor fault pulse signals.

Abstract: An oven that is controllable by a conversational style voice interaction with a user. It includes voice recognition system for listening to the user and a speech synthesizer for talking to the user. Operation occurs initially in a first voice recognition mode for recognizing one of a group of possible first voice commands from the user. After recognizing a particular first voice command, operation continues in a voice synthesizing mode wherein the user is asked to make some choices which confirms or "narrows" the first voice command. After synthesizing, operation continues in a second voice recognition mode for recognizing a particular one of a second group (less in number than the first group) of possible second voice commands from the user. After recognizing a particular second voice command, the oven operates according to the preprogrammed instructions corresponding to the first and second voice commands.

Abstract: This drop-down toaster has a bread support and a door at the bottom of each toasting compartment. The door has a series of vent holes for air convection which produces improved uniformity in the toast. The door and bread support are held closed by rollers on solenoid-controlled sliding bars. The rollers allow the door to swing open before the bread support is released, and they return the door and bread support to their normal condition automatically by a cam action. The bread support is cammed upwardly before release to dislodge bread from the toasting compartment guide wires. An electronic timing circuit is located in a base underneath and spaced vertically from the toasting section so that it is not affected by heat from the toasting section. The timing circuit is compensated in accordance with previous use rather than by sensing the temperature of the toasting compartment.

Abstract: An automatic temperature control device includes a series-connected temperature setter, a comparison unit whose second input is connected to an actual temperature transducer of the controlled entity, a deviation signal amplifier, and a regulating unit. The device also includes a unit used to check the circuit of the transducer for continuity, said unit being connected to the output of the latter, and an electronic switch whose control input is connected to the output of the check unit to apply to the input of the actuator a periodic pulse sequence generated while the circuit of the transducer is open.

Abstract: A heating apparatus, such as an electric oven or an electronic oven including a voice recognition part which recognizes voice command of the user and produces a recognition code by receiving the voice command and performs operation by the voice command. Heating sequences are preliminarily stored in a memory of a control part, and one of them are selected by a recognition code produced by the voice recognition code, and preset in the memory. Heating members are controlled in a manner to heat the heating object according to the preset heating sequence. Such selection and presetting of the heating sequence is performed only when at least two sequential voice commands are fed to the voice recognition part in a predetermined order.

Abstract: A fluid circulating system primarily designed for use with a thermal blanket or pad and being temperature controlled so that both heating and cooling effects may be produced through the preheating or precooling of fluid in a reservoir tank or like container which, wherein the fluid is in turn forced through the thermal blanket to provide the proper heating or cooling as desired. A standby switching mode is included to prevent circulation of the fluid through the thermal blanket by a pump structure until the fluid reaches a preselected temperature has been reached. Heating and cooling transfer elements are disposed to the fluid within the reservoir tank thereby eliminating the need for condensor structures and the like and allowing for a compact overall unit to provide the required fluid circulating throughout the thermal blanket.

Abstract: A ceramic encased thermocouple placed within a kiln electrically controls an array of signal classifiers which, in turn, control the operation of the kiln heating elements. The temperature value at which the classifier array terminates the whole kiln heating operation is preselected as one of a plurality of discrete predetermined values corresponding to pyrometric cone temperature values.

Abstract: A peak load control apparatus with operating mode selection for an electric heating system having a plurality of electric heating units arranged in two or more groups in different rooms is disclosed. When the current carried by the feeder line exceeds a predetermined value a peak load trigger or flip-flop which receives a signal proportional to the feeder current from a detector delivers a peak load signal to a first control circuit or monostable which cuts power to a first selected group of heating units for a predetermined period, and to a second time control circuit or monostable which cuts power to a second selected group of heating substantially at the end of the period during which power is cut off to the first group of heating units. The heating units are provided with programmable thermostats connected to operating mode selector switches which are connected to the feeder line.

Abstract: A control system for applying operating power to an analytical furnace includes a first circuit providing output signals consisting of a series of binary bits in a predetermined pattern with each bit corresponding to a unit of power to be applied to an analytical furnace according to the pattern of bits and a control circuit coupled to the first circuit and including output terminals for coupling the control circuit to an analytical furnace. The control circuit responds to the binary bits to provide pulses of operating power to the output terminals in a sequence corresponding to and controlled by the binary bits. The pattern of bits provides stepwise increasing temperature levels for the analytical furnace in a very predictable and controlled fashion such that samples combusted by the furnace will emit specimen gases associated with different compounds containing the specimen gas at different temperature levels.

Abstract: The temperature of an electrically heated element is controlled by applying a current until the element reaches a threshold temperature, preferably determined by the expanded length of the elements, and then applying a predetermined voltage-current condition for a selected period of time. This is followed by repeated applications of such voltage-current conditions in response to the cooling of the heating element back to the threshold temperature.

Abstract: A kiln temperature controller is provided comprising a circuit for providing a first signal representative of a selectable kiln temperature and a temperature detection circuit for providing a second signal representative of the detected kiln temperature. The temperature detection circuit comprises first and second thermocouples disposed in the kiln and in the temperature controller, respectively. The first and second thermocouples are coupled in series and in opposite polarity. A solid state temperature sensing circuit is provided in the kiln temperature controller, the temperature sensing circuit being coupled in series with the first and second thermocouples and providing an output signal having a polarity opposite that of the second thermocouple to nullify ambient temperature variations of the kiln temperature controller.

Abstract: An electric blanket control effective to deactivate power to the blanket's resistance wire heating circuit, the control having a capacitance detector constructed and adapted to respond to differences in the capacitance of the heating circuit attributable to the presence or absence of the user under the heating wire of the blanket, and a switch responsive to the detector adapted to interrupt power to the heating circuit when the capacitance value of the heating circuit indicates the absence of the user.

Abstract: A controller system using high frequency switching by providing a bilateral switch gated on and off at a frequency about ten times the source frequency and the duty cycle determined by pulse width modulation of the high frequency waveform in accordance with window heater temperature.

Abstract: A control system and method for an apparatus to glow discharge treat (such as ion nitride) a workpiece. The apparatus includes a housing to receive a workpiece and a low pressure atmosphere of ionizable gas (nitrogen and hydrogen for nitriding), and connectors for establishing a glow discharge in the gas with the workpiece connected as the cathode. The control system and method automatically control the apparatus throughout the process, utilizing operator selected parameters (such as warm-up time, processing time, workpiece operating temperature and chamber pressure). The control system divides the selected operating temperature by the selected warm-up time to provide a straight line increase per unit time of the workpiece temperature. Initially the control system accumulates the increases at a rate higher than the straight line increase and then, as the workpiece approaches the selected operating temperature, the control system accumulates the increases at a rate less than the straight line increase.

Abstract: A control system for a heating unit that has controls for comparing a variable electrical signal that has a value in relation to the output temperature of the heating unit and a selected electrical signal that has a value in relation to a selected temperature setting to control the operation of the heating unit to tend to produce an output temperature substantially equal to the selected temperature, the controls including a control device having a rod and tube temperature sensing unit for providing linear motion of a part thereof in relation to the output temperature of the heating unit and having a potentiometer provided with an electrical output producing part operatively interconnected to the movable part of the rod and tube unit so as to produce the variable electrical signal in relation to the output temperature of the heating unit.

Abstract: Apparatus for disconnecting electrical powered devices from a source of electrical energy when the use of the devices is no longer needed. The apparatus includes an electrical switch movable in response to an actuation member. The switch is connected between a source of electrical energy and an electrical powered device so as to selectively connect/disconnect the device to the source of electrical energy depending upon the use of the actuation member. A second electrical switch, also responsive to the actuation member, is connected between the source of electrical energy and another electrical powered device, such as a heating/air conditioning unit, to connect/disconnect the heating/air conditioning unit to the source of electrical energy. One temperature responsive device is associated with the second electrical switch in order to maintain the room temperature above a predetermined minimum temperature.

Abstract: A microwave oven includes a magnetron, a blower fan system, and a gas sensor for detecting an exhaustion gas concentration developed from an oven cavity. When the exhaustion gas concentration exceeds a preselected value while an actual cooking operation is conducted, the gas sensor develops a first detection output to complete the actual cooking operation. While the actual cooking operation is not conducted, the gas sensor functions as a gas leak alarm sensor. When an ambience gas concentration shows an abnormal value, the gas sensor develops a second detection output to announce a dangerous gas leakage. While the actual cooking operation is not conducted, the blower fan system is intermittently energized to introduce the ambience air toward the gas sensor for monitoring purposes.

Abstract: A solid-state control circuit for selectively operating a deep fat fryer in a normal cook mode, a lower temperature hold mode, a fat melt mode and a safety thermostat test mode. During operation in the cook mode, a reference bias voltage is coupled to one input of a voltage comparator, and an operating bias voltage dependent on the temperature control setting and the actual cooking fat temperature sensed by a NTC resistive sensor is coupled to a second input of the comparator such that the comparator is effective to enable heating elements in the cooking fat when the fat temperature drops below the preset level. After a predetermined time interval during which the fryer is not being used, a timing circuit acts to vary the reference bias voltage and the operating bias voltage supplied to the comparator and thereby reduce the temperature of the fat to the lower preset hold mode temperature.

Abstract: A power control system is disclosed which controls the power output of one or more resistive heating elements in response to operator selected power level settings. Control of power to the elements is accomplished by generating a multi-bit binary word representing a selected power level, each bit being operative to control the application of power to the element during a different control interval. A control word is generated for each element and is updated once during every associated control period, a period comprising a number of intervals equal to the number of heating elements. The heating elements are of a type which draw a relatively high current during a transient heat-up period. The application of power to other elements is inhibited when one of the elements is having power applied thereto during its transient period. Power control for each element is staggered by testing a bit of different positional value in each word during any given interval.

Abstract: A power control method and system for a cooking appliance using a high inrush current element in which the instantaneous glow from the heater element is utilized to inform the operator of appliance turn-on. The power control includes a logic arrangement for detecting the transition of the appliance from an OFF condition to a selected one of a plurality of power level settings. Prior to energizing the heating element at the selected power level, the control energizes the element for a preselected transient time at a level to produce a visible glow.

Abstract: A control system having a control unit provided with a single thermostatically operated control device for operatively interconnecting a heater to a source of energy when the output temperature effect of the heater is below a predetermined setting of a selector of the control unit and to disconnect the heater from the source of energy when the output temperature effect of the heater is above the predetermined setting of the selector, the single thermostatically operated control device also operating an indicating light to indicate that the output temperature effect of the heater is still above a certain value only when the selector of the control unit is in an "off" setting thereof. The selector of the control unit also operates a pilot light to indicate that the selector is set in an "on" setting thereof.

Abstract: In an electronic control device for electric ranges having a plurality of individual heat settings to selectively energize a heating element of the range under the control of a digital input to produce switching pulses having different on-off ratios, each heat setting has an associated time controlled constant power period in the start-cooking or roasting range, and in the subsequent finish-cooking range there are produced switch-on and switch-off pulses having a constant time pattern at every heat setting, while the time duration of the constant power period and the duration of the switch-on pulses in the finish-cooking range are different from one heat setting to another.

Abstract: An automatic heat control apparatus for use with an electric heating element in a kiln or the like comprises a first power controller having a plurality of on and off intervals. The first controller supplies electric current to the kiln heating element during its on intervals, and further includes means for adjusting the duration of the on intervals relative to the off intervals. A constant speed electric motor is mechanically coupled to the first power controller for gradually increasing the duration of the on intervals and decreasing the duration of the off intervals; such control ensures that the temperature inside the kiln increases very gradually to lessen the risk of breaking the ceramic material being fired. Furthermore, the average speed of the motor may be controlled by means of a second power controller, similar to the first controller, having a plurality of on and off intervals which intermittently energize the motor for rotation thereof.

Abstract: A switching means detects a malfunction due to an open circuited or broken state of a temperature sensing element. The switching means overrides a normal control by the temperature sensing element of a heater, so the heater is de-energized by the switching means and possible uncontrolled, dangerous activation of the heater is prevented.

Abstract: A control for selectively energizing a heater provided to raise the temperature of lubricating oil of a compressor employed in a refrigeration unit. The control includes a thermostatically operated switch provided to sense a temperature indicative of lubricating oil temperature. The switch connects the heater to a source of electrical energy when the sensed temperature falls below a predetermined value and the compressor is inoperable. When the compressor is operable, the heater is rendered inoperable irrespective of the sensed temperature.

Abstract: The glass pane of a vehicle window is provided on the surface of its central viewing area with a plurality of spaced, parallel linear heating resistors. First and second buses, disposed laterally of the central viewing area, extend transversely of the resistors and supply electric power to the resistors. A miniature transistorized control circuit mounted at a corner of the pane away from the central viewing area controls the supply of power to the buses. A plurality of moisture sensing, electrically conductive probes are provided on the pane at widely spaced zones and are connected to the input terminal means of the control circuit. Each probe includes a first portion coextensive in length with a resistor and running parallel thereto. One of the probes has a second portion parallel to and closely spaced from one of the buses. The control circuit responds to detection of fogging of the pane by anyone of the probes.

Abstract: A control for a resistance solder unit for maintaining solder probe temperature within an acceptable range is provided using a redundant interlocking switching circuit. A pair of dual, single pole, single throw, variable time delay electronic relays, and a pair of dual, single pole, single throw electrical relays may be interconnected into the supply line for the AC to DC soldering transformer to control the time and duration of current to a resistance soldering probe. Included may be an autotransformer-coupled feedback from the resistance solder ground return of the soldering probe. Typically, visual and audible signals provide probe power status.