Abstract: A MEMS vapour bubble generator that uses a heater in thermal contact with a liquid to generate a bubble. The heater is energized by an electrical pulse that is shaped to have a relatively low power, sub-nucleating portion and a high power portion that nucleates the bubble. The thermal energy transferred to the liquid by the sub-nucleating portion speeds up the nucleation of the bubble across the surface of the heater during the nucleating portion. This produces larger, more stable bubble having a regular shape.

Abstract: A controlled start up technique may eliminate the excessive peak junction temperature by controlling the speed of the electric device. Lower speed may result in reduced power to the load. Reduced power may result in reduced losses to maintain reliable operating junction temperatures. Once the junction reaches the predetermined temperature limit, speed may be controlled to hold the junction temperature constant. As time elapses, the coolant temperature may reduce, thereby allowing a higher power level without an increase in IGBT temperature. Unlike conventional methods which may allow for full power continuously upon start up, thereby either potentially causing a high temperature shut-down condition or requiring additional thermal inertia to handle a high heat load due to a continuous full-power start up, the controlled start up eliminates the design penalties for extensive thermal enhancements to accommodate the occasional extreme hot start up.

Abstract: A method and a circuit for preventing over-heat of heat-generating device which are provided with a trigger circuit and a microprocessor on a heater circuit. And the trigger circuit is connected with a power source and a heat-generating device for heating the heat-generating device. The above-mentioned heater circuit is connected with a thermo fuse, a resistor and a reactive trigger circuit. Another end of the reactive trigger circuit is connected with the microprocessor for advancedly detecting whether the microprocessor is in abnormal condition. Once the microprocessor is damaged, the power source, the thermo fuse and the resistor make a loop and the resistor is heated to ruin the thermo fuse for terminating heating. Also, when the microprocessor works normally, the heater circuit and a switch for controlling temperature on reactive trigger circuit are detected to determine whether to terminate the heater circuit.

Abstract: A system is disclosed for detecting the occurrence and extent of waterlogging in steam heating coils which consists of a series of two or more sensors disposed to measure temperature at strategic locations on the heating coils of a steam heat coil panel, a recording device which logs and stores the temperature measurement data at pre-defined incremental intervals over a significant length of the steam heating cycle, and a method for displaying and interpreting the data to accurately identify the existence and extent of waterlogging within the steam heating system. The temperature sensors preferably are attached to the outside wall of the steam heating coils and transmit data to an electronic recording device. In a preferred embodiment the data is displayed as a series of line graphs which can be analyzed by the use of described techniques to identify the occurrence and location of waterlogging within a steam heating coil.

Abstract: A self-regulating heater including a semiconductor for converting electrical energy to heat. A temperature sensitive element is used to bias the semiconductor as a function of temperature. The heating element has an advantage that its maximum temperature is limited by the biasing network, yet full power is available just below the limit.

Abstract: A fluid heating system includes a fluid receptacle having a fluid reservoir, and a heating control system configured to heat fluid retained within the fluid reservoir. The heating control system includes a processing unit, at least one fluid temperature sensor positioned on or within the fluid receptacle, a heating element configured to heat fluid within the fluid reservoir, and a power switch disposed within an electrical path between the heating element and the processing unit. The processing unit is configured to selectively activate and deactivate the heating element through the power switch based on the fluid temperature detected by the fluid temperature sensor.

Abstract: A window defroster system that includes a heater grid and a controller. The controller includes a pulse width modulator configured to provide a driving signal to the heater grid. The driving signal has an initial heating portion and a pulsed portion. The initial heating portion provides an initial voltage that is greater than an optimal operating voltage of the heater grid, the pulsed portion provides a pulsed signal with a pulsed high voltage that is greater than the optimal operating voltage.

Abstract: A power module to regulate delivery of power to one or more loads is disclosed. The module includes a logic circuit configured to generate one or more control signals indicative of the power level to be applied from an external power supply coupled to the power module to the one or more loads, an electromechanical device configured to electrically connect the external power supply to the one or more loads based on the one or more control signals from the logic circuit, a user-controlled circuit configured to provide a signal indicative of a power level to deliver to the one or more loads, the signal is based on input received from a user-controlled actuator configured to be placed in one of a plurality of positions corresponding to user-provided input, and a housing configured to receive the electromechanical device.

Abstract: A system and method for preventing crosstalk noise from being superimposed on a read signal due to noise from a heater line for a slider in a recording disk drive is disclosed. A heater line pair to the slider is not grounded but is in a floating state with respect to an actuator support structure. A heater driver allows a heater current to flow between a positive power supply voltage and a negative power supply voltage. The heater line pair is not grounded, so an impedance is high as viewed from a magnetic disk. Thus, it is possible to effectively suppress a noise transmitted from the magnetic disk and read signal quality is kept from deteriorating due to the crosstalk from the heater line.

Abstract: A sensor circuit provides a signal to a microcontroller to indicate parameters of an environmental condition to which the sensor circuit is exposed, such as temperature. The sensor circuit and microcontroller are mounted in a common housing, with an output lead indicating an on/off output based on predetermined parameters of the environmental condition. By access through the output lead, the microcontroller can be reprogrammed to change the predetermined parameters controlling the output state of the switch.

Abstract: A switching power supply includes a sensor for detecting that the output level of the switching power supply has exceeded a rated output level, and a memory that stores data for estimating temperature change of a heat-producing component during a period in which the output level is higher than the rated output level. The data is differentiation data of a curve that represents temperature change characteristics of the heat-producing component. An estimated temperature of the heat-producing component is computed based on the time elapsed from when the output level of the switching power supply exceeds the rated output level and the differentiation data. When the estimated temperature of the heat-producing component reaches an upper threshold temperature, a switching element is deactivated.

Abstract: An electronic control circuit, for use in connection a hot melt adhesive dispensing system having a relatively large applicator head, has a plurality of heater circuits and a plurality of temperature sensors disposed upon different regions of the relatively large applicator head, wherein the electronic control circuitry can effectively interface between the plurality of heater circuits and the plurality of temperature sensors, and the adhesive supply unit (ASU) hose and head connector, so as to control individual ones of the plurality of heater circuits and thereby ensure that all of the heater circuits will maintain the same temperature setting throughout all regions of the applicator head.

Abstract: A heater lamp control apparatus and method of detecting an input AC voltage and providing a pulse signal corresponding thereto, includes an AC voltage phase detection unit to detect a phase of the inputted AC voltage when a magnitude of the inputted AC voltage is over a predetermined level. The heater lamp control apparatus also includes a pulse signal generation unit to generate a pulse reference signal based on a result of the detection, a pulse delay signal that is phase-delayed, and a heater lamp control pulse signal based on a result of the comparison of the magnitudes of the pulse reference signal and the pulse delay signal. The heater lamp control pulse signal includes a control unit to control a drive-timing of the heater lamp based on the heater lamp control pulse signal. Thus, the heater lamp control apparatus minimizes a flickering phenomenon as well as an amount of electric power consumed in a heater lamp.

Abstract: A system for adjusting parameters of a temperature sensor for settling time reduction is disclosed. The system includes an input for receiving a signal for triggering an adjustment of one or more parameters associated with one or more portions of the temperature sensor. And, an adjuster that includes a current sourcing/sinking adjuster, a feedback loop current adjuster and a feedback loop resistance adjuster coupled to the input. The adjuster adjusts one or more voltages associated with one or more portions of the temperature sensor in response to a receipt of the signal for triggering an adjustment to achieve the settling time reduction.

Abstract: A user control generates a heat level input signal responsive to a user of a cooktop heating element. Logic generates an output signal having a duty cycle corresponding to the input signal. An electromechanical device connected to apply power from a source to the heating element in response to the output signal.

Abstract: A control circuit includes a drive circuit which applies a drive voltage to a semiconductor device having an overheating protection function according to an externally supplied signal; and a current detecting circuit which outputs a detection signal when a drive current flowing through the semiconductor device exceeds a predetermined threshold current. The semiconductor device incorporates a semiconductor element, a temperature detecting circuit for detecting temperature increase of a chip, and an interrupting circuit for interrupting an input to the semiconductor element according to a detection output of the temperature detecting circuit.

Abstract: A method and apparatus for controlling the electric resistance heating of a metallic chemical preconcentrator screen, for example, used in portable trace explosives detectors. The length of the heating time-period is automatically adjusted to compensate for any changes in the voltage driving the heating current across the screen, for example, due to gradual discharge or aging of a battery. The total deposited energy in the screen is proportional to the integral over time of the square of the voltage drop across the screen. Since the net temperature rise, ?Ts, of the screen, from beginning to end of the heating pulse, is proportional to the total amount of heat energy deposited in the screen during the heating pulse, then this integral can be calculated in real-time and used to terminate the heating current when a pre-set target value has been reached; thereby providing a consistent and reliable screen temperature rise, ?Ts, from pulse-to-pulse.

Abstract: Semiconductor manufacturing equipment includes a heater element configured to heat a wafer, a first connection part and a second connection part which are integrated with the heater element, configured to apply voltages to the heater element, a first electrode contacted with and fixed to the first connection part on a first surface of the first electrode configured to be to apply a voltage to the first connection part, a second electrode which is contacted with and fixed to the second connection part on a second surface of the second electrode, configured to apply a voltage to the second connection part, and the second surface is perpendicular to the direction of the first surface.

Abstract: The cooker appliance (1) has a horizontal cooking surface (10) of a given height (Hw), a gas “G” manifold assembly (2) with a plurality of taps (8) provided with a rotary shaft (9) for regulating the gas flow (Q), supported in a fixed position apart from one another on a front support wall (11) and at a given height (Hv) of the appliance. The control panel (3) provided with each of the rotary tap control knobs (4) is orientable up to as much as a right angle (A) by means of a pivoting axle (6), whereby the control knobs (4) are positioned either downwards in a rest position or else upwards at the level of the cooking plane (10) for the regulating manoeuvre, on a horizontal plane (P) at an increased height “Hv+Hv”. The control knob shafts (7) are coupled to the taps (8) by means of a flexible shaft (5) for transmitting the respective rotation, extended within a cavity (3a) for housing the taps (8) which is formed by the control panel.

Abstract: A controller adapted to control the temperature of a heating elements with a wide range of positive temperature coefficient of resistance, including very low values, using a sensor in line with the heating element. The controller is able to take account of non-constant mains power supplies and variation in the element resistance over time.

Abstract: The present invention relates to a non-electromagnetic wave temperature controller for a heating cable and a method therefor, which can perform heating and temperature detection in a non-electromagnetic fashion without short-circuiting one end of the heating cable that is used in warmers, such as electric floors, electric mats and electric fomentation devices. Furthermore, the present invention relates to a temperature detection non-electromagnetic heating cable and a temperature controller, which can reduce the amount of heat and control temperature without using a separate temperature sensor when the temperature of the heating cable is controlled or an arbitrary portion of the heating cable is overheated, and can prevent a magnetic field from being generated in the heating cable without short-circuiting one end of electrical heating wires and intercept the generation of a leakage electric field.

Abstract: A method for controlling and regulating an electrical heating of a probe situated in the exhaust system of an internal combustion engine, a total heating power of the probe being set, and an actual temperature value of the probe being determined by measuring a characteristic parameter, e.g., a resistance. To prevent overheating of the probe ceramics, and therefore over-compensation of aging effects when using such a method, a rated heating power is determined by way of a program map as a function of operating points of the internal combustion engine; a control heating power is determined from the actual temperature value and a new setpoint value in a controller; and the total heating power is formed as the sum of the rated heating power and the control heating power. Moreover, due to this procedure, the regulating reserve of the controller is retained in wide ranges of the operating points. A cost advantage is yielded, because a measuring resistor and an analog-to-digital converter can be omitted.

Abstract: A circuit is disclosed for detecting and eliminating the buildup of snow and/or ice on the viewable face of an LED traffic signal lens. The circuit measures the ambient temperature within the LED signal, and when the temperature falls to a level where snow and/or ice accumulation can occur, the circuit begins looking for snow and/or ice buildup on the lens of the LED signal. An infrared LED transmits a signal which is reflected when snow or ice is present on the lens of the traffic signal. When the reflected signal is received by an infrared receiver, it sends a signal to a microcontroller, which analyzes the signal to determine if it is a valid signal. If it is, a heater is turned on until the ice and snow are removed.

Abstract: A power management system for managing the power supplied to a plurality of warming elements in a brewing machine, so as to conform to pre-set power safety requirements.

Abstract: A circuit includes a switching device for controlling a power signal to be applied to a heating device. A control circuit is configured for comparing a temperature signal, indicative of the temperature of the heating device, to a temperature setpoint to generate a gate pulse signal that controls the duration of the power signal to be applied to the heating device. The control circuit is further configured for comparing the duration of the power signal to be applied to the heating device to a minimum pulse duration and, if the duration of the power signal to be applied to the heating device is at least equal to the minimum pulse duration, providing the gate pulse signal to the switching device.

Abstract: A fuser-controlling apparatus for generating a power synchronization signal and detecting a power voltage. The fuser-controlling apparatus comprises a power synchronization signal generation circuit for outputting a power synchronization signal for synchronizing fuser operations with a power voltage, a power voltage detection circuit for detecting a level of the power voltage and for outputting a level of the power voltage, and a control unit for controlling a voltage to the fuser in a phase control manner based on the power synchronization signal and the detected level of the power voltage. The fuser-controlling apparatus can produce a power synchronization signal at the zero-crossing points of the power voltage regardless of the levels and frequencies of the power voltage. Accordingly, the fuser-controlling apparatus can instantaneously perform phase and power controls based on such a power synchronization signal, resulting in improvements to the power factor and flicker characteristics of the system.

Abstract: A system configured to provide food storage, preparation, and delivery in a finished cooked state includes a computer control interface, a freezer/refrigeration module, a food transport mechanism, a heating/cooking module, and a delivery area. The meal system is configured to provide food storage, preparation, and delivery in a finished cooked state. The system may be configured in the form of an independent unit or in the form of a combination of separate modules. The computer control interface, freezer/refrigeration module, food transport mechanism, heating/cooking module, and delivery area may be communicatively interconnected wirelessly or non-wirelessly.

Abstract: A system and method for controlling a heating and ventilating system is provided. The method includes determining a demand for heat and creating an air flow. In addition, the method includes sensing an outlet discharge temperature of the air flow and increasing the temperature of the air flow to a selected value. Generally, the method further includes increasing the air flow velocity, while maintaining the discharge temperature of the air flow to the selected value. The system for controlling a heating and ventilating system includes an input for receiving a demand signal and a heater control circuitry for controlling the heat output of a heat source. In addition, the system includes ventilation control circuitry for controlling the flow of an air source and an outlet air temperature sensor. Finally, the system preferably includes a microcontroller for controlling the heat output and the flow of the air source.

Abstract: The present invention relates, in general, to a temperature controller and heating cable used for electric heating bedding, such as an electric blanket, electric papered floor or electric fomentation device, or warmers and, more particularly, to a controller having a safety device, which can immediately shut off the supply of power when the disconnection, breakage or local overheating of a heating cable occurs while preventing the generation of an induced magnetic field and the leakage of an electric field, in warmers, such as simple bedding or fomentation devices that are operated by allowing a user to simply control a heating temperature to a high or low level without measuring the temperature of a separate heating cable. The controller, having a safety device, for blocking electromagnetic waves includes a switch unit, a heating current U-turn and detection unit, a fuse, and a cutting operation unit.

Abstract: A heating structure and its temperature control method having therein a heat generating line and a controller. The heat generating line includes a PTC element and a short circuit line serially connected having an insulating fusible layer separating them. When a user sets a heating temperature, electric current is conducted to heat the PTC element, alternative string wave signals input into an AC phase shaping circuit and an AC phase delay shaping circuit are converted into square wave signals; and by measuring with a microprocessor at a given time the phase shift between the two phase shaping circuits to control the switch of a trigger circuit, the PTC element can keep on heating or reduce its temperature to therefore keep the heat generating line at a predetermined working temperature. The structure is applicable to heat generating devices such as electric ovens and heating blankets etc.

Abstract: The present invention relates to a forced-air electric heater control system for HVAC systems. One embodiment utilizes two heat sensors which are positioned upstream and downstream, equidistant from the heating element(s). The control system, in this embodiment, takes the difference between the temperature signals, thereby eliminating any radiant heat factor, and the resulting signal is used to control the heater. In other embodiments, the method senses upstream and downstream temperatures, determines air velocity in the duct, determines the amount kilowatts (KW) or other heat per unit time or power based thereon, and enables the power control switch when the resultant is less than a predetermined value. Alternate systems initially test for air velocity by application of nominal power, and then use the measured velocity and the downstream temperature to obtain a control signal for the heater. A pressure differential may be used. The systems compensate for radiant heat factor.

Abstract: The present invention generally relates to a high-frequency pulse oscillator, and more particularly to a high-frequency pulse oscillator adapted to provide pulse currents having a high frequency and large amplitude so as to transition metallic materials into a plastic state for ease of processing or for closing microcracks formed in metallic parts in order to recover mechanical characteristics thereof. The high-frequency pulse oscillator of the present invention comprises a controllable rectifier, a switching section, and a control system. The controllable rectifier rectifies alternating currents supplied from a current source to output currents having a predetermined waveform, according to a control signal from the control system. The switching section generates pulse currents using the currents from the rectifier, according to another control signal from the control system.

Abstract: A temperature control system for a bathing unit that includes a water holding receptacle and a heating module. The temperature control system comprises a plurality of actuators associated to the heating module and a temperature regulation device in communication with the actuators. The plurality of actuators are adapted for acquiring a first set of actuation patterns for causing the heating module to acquire a non-heating state and a second set of actuation patterns for causing the heating module to acquire a heating state. The temperature regulation device is operative for controlling the plurality of actuators to cause the heating module to acquire either one of the heating state or the non-heating state and for selecting a configuration from the first set of actuation patterns for causing the heating module to acquire the non-heating state. Alternatively, the temperature control system includes a solid state device associated with the heating module.

Abstract: A cooking appliance includes a heating system which is preferably capable of combining radiant, convection, microwave and conduction heating techniques to perform a cooking operation. The cooking appliance includes a convection fan and at least one heating element. A controller is provided to regulate a triac to maintain a desired heater intensity through phase angle firing. Essentially, an AC waveform provided to the heater resistor travels through the triac which is turned on by the controller at predetermined points in the AC waveform, with the delay from a zero point waveform crossing functioning to regulate the amount of power sent to the heater resistor. When the signal from the controller is removed, the triac advantageously turns off at the next zero crossing of the AC waveform such that an operationally and economically effective control system is provided.

Abstract: A cooking appliance includes a heating system which is preferably capable of combining radiant, convection, microwave and conduction heating techniques to perform a cooking operation. The cooking appliance includes a convection fan and at least one heating device. A controller is provided to regulate a triac to create a variable fan speed and variable heater intensity through phase angle firing. Essentially, an AC waveform provided to the fan motor and/or the heater resistor travels through the triac which is turned on by the controller at predetermined points in the AC waveform, with the delay from a zero point waveform crossing functioning to reduce the amount of power sent to the heater resistor and fan motor. When the signal from the controller is removed, the triac advantageously turns off at the next zero crossing of the AC waveform such that an operationally and economically effective control system is provided.

Abstract: Provided are a temperature control method and apparatus for driving a polymerize chain reaction (PCR) chip. In the temperature control apparatus, which is for a polymerize chain reaction chip, PCR chips receive electric power from the outside and generating heat to maintain a predetermined temperature and for outputting actual temperature information to the outside. electric power supply units supply electric power to the PCR chips according to input control signals, and a controller generates the control signals based on control information including pre-established control temperature and control time information and the actual temperature information supplied from the PCR chips in order to supply the control signals to the electric power supply units. In the present invention, it is possible to examine various kinds of DNA at the same time because the temperature control apparatus controls the temperatures of DNA samples at the same time.

Abstract: A mobile communication terminal device is disclosed having elements for detecting moisture in the device. These elements include the following precautionary features: a memory for recording a circumstance under which the detection of moisture takes place, a shutdown feature for shutting down the mobile communication terminal device at least partially if moisture has been detected, and a feature for determining two circumstances, namely that the mobile communications terminal has been at least partially shut down as a result of a detection of moisture and that the mobile communication terminal device has been connected to an external power supply and subsequent current is being drawn from the power supply. Once these two circumstances have been detected, a mode is activated by which the mobile communication terminal device is subjected to a heating phase and as a result, in turn, to a drying phase.

Abstract: An immersion heater device for aquariums and the like. The heater device has a casing which contains a heating element. The casing, at least in the region of a radiant zone of the heating element, includes a layered structure having at least one layer of metal material and one layer of plastic material. The layer of metal material is interposed between the heating element and the layer of plastic material.

Abstract: A cooking appliance employing rapid cook technology includes an electronic oven control system employing an alpha-numeric data entry and display arrangement. The cooking appliance includes a display which incorporates a series of vertically spaced information display zones, with each of the zones being capable of displaying both alpha and numeric data to a user of the appliance. Text and numeric data can be entered by the user through a ten-digit keypad provided on a control panel of the appliance. Each labeled numeric key (0–9) can be used to input a corresponding numeric data symbol, as well as additional text information. This arrangement advantageously makes purchasing and operating a sophisticated cooking appliance more appealing and less intimidating to a consumer.

Abstract: An electric clothes dryer heater system including a heater element and a controller operationally coupled to the heater is provided. The controller is configured to provide an AC sine wave to a heater element of an electric clothes dryer, stop providing at a zero crossing of the AC sine wave, monitor the AC sine wave for a subsequent zero crossing and reprovide the AC sine wave to the heater element at the subsequent zero crossing.

Abstract: A heater control is performed without problems when a normal detection of a power source frequency cannot be performed. A heater control apparatus is configured and arranged to be operable by an alternating current having one of a plurality of frequencies. The heater control apparatus detects a zero-cross point of a voltage waveform of the alternating current to be supplied to a heater so as to generate a zero-cross signal and controls an electric power supply to the heater by using the zero-cross signal as a reference. At a time of tuning a power on, the frequency of the alternating current is tentatively determined before the frequency is detected so as to control the electric power supply to the heater based on the tentatively determined frequency, and to control the electric power supply to the heater, after the frequency of the alternating current is detected, based on the detected frequency.

Abstract: A device having a resistor and a heater disposed proximate to the resistor and capable of raising the temperature of the resistor. The device further includes a dieletric disposed between the heater and the resistor and a tuner electrically coupled to the resistor. The heater adjusts the resistance of the resistor in response to the tuner.

Abstract: A method and system for ensuring compliance with regulatory requirements to train, test, perform, evaluate and document identified covered tasks and provide the means to meet governmental and/or industrial standards including measuring applicable physical parameters, recording the steps involved and values of the parameters measured, comparing the steps and values recorded for each covered task with pre-established approved standards and providing a record identifying covered tasks that meet or that do not meet pre-selected approved standards.

Abstract: An optical communication module includes an optical radiation source as well as control circuitry to control the temperature and the power emitted by he optical source. In order to permit soft start-up of the source while avoiding undesired wavelength variations, the optical source is pre-heated before being caused to emit optical radiation. This may be effected by initially heating the optical source to an initial temperature using the thermoelectrical conditioner associated therewith as a heater and subsequently causing a partly under-threshold current to flow through the source, thus causing the source to be heated while still emitting negligible optical power.

Abstract: A method for controlling power to an electrical load using dual pulse width modulation (PWM) to minimize in-rush current to the electrical load, such as a heater element. An output from a power source, supplying an alternating current, is modulated by a first PWM control signal to provide a first modulated power level to the electrical load. The first modulated power level is modulated by a second PWM control signal to control power supplied to the electrical load at the first modulated power level. The first PWM control signal operates to control the number of half cycles of current in order to provide one-third, two-thirds or full cycle power. The second PWM control signal operates to define a duty cycle and period for providing the power defined by the first PWM control signal to the electrical load.

Abstract: A control circuit for a heating pad. The control circuit includes a two-pole, four-position slide switch. The four positions of the two-pole, four-position slide switch include off and three different heat settings of the heating pad. The control circuit also includes three heat setting indicators that are alternatively illuminated when the switch is in the three different heat settings. Diodes are used to direct electrical currents through the indicators as appropriate. The diodes and the two-pole, four-position slide switch are arranged so that current may be appropriately flow through, or may be blocked from flowing through, the indicators when the two-pole, four-position slide switch is in each of the three heating settings.

Abstract: In one embodiment of the present invention, a power controller for an AC load comprises: a user interface adapted to interact with a user to produce at least one user interface signal; and a control module adapted to electrically couple a line voltage supply, electrically couple the AC load, and provide electrical power to the AC load as a function of the at least one user interface signal by implementing a low-flicker, cycle-skipping control algorithm, the control algorithm comprising a plurality of cycle patterns, the cycle patterns comprising a plurality of main power levels.

Abstract: A temperature control system for reducing flicker in an electrical resistance heater comprising: an electrical resistance heater divided into at least two electrical loads and; a source of electrical power for repetitively supplying electrical power to each of the at least two electrical loads at successive different time sub periods within a predetermined time period, wherein the sum of the power supplied to the at least two electrical loads is equal to the total power supplied to the electrical resistance heater during the predetermined time period.

Abstract: A control structure and method for controlling a sensor heater including a power supply connected to a switching device for pulse width modulating a voltage from the power supply. The switching device is further connected to a resistance heater. A microcontroller having a single output is connected to the switching device and a single input from the microcontroller is connected to a high side of the resistance heater. The microcontroller determines a pulse width modulation duty cycle to maintain a constant power dissipation of the resistance heater.

Abstract: An image formation apparatus includes a fixing heater, and a zero-cross detector that detects zero-cross points of a frequency of an alternating current (AC) power supply connected to the heater. The image formation apparatus also includes a controller that controls light-on of the heater by pulse-width-modulation (PWM)-controlling the frequency of the AC power supply, that controls a duty width of a PWM control signal for the frequency of the AC power supply for a half period that corresponds to a period between the adjacent zero-cross points detected by the zero-cross detector, and that controls an amplitude of an input current from the AC power supply so that a waveform of the input current becomes a rough approximation of a sine wave.