Abstract: In a power-supply control device, power supply to loads is controlled by driving circuits separately switching on or off FETs, respectively. In a state in which the connection destination of a fuse element is the FET, a microcomputer provides an instruction to switch the FET off. Then, the microcomputer determines whether or not a current is flowing through the FET. Upon determining that a current is flowing through the FET, the microcomputer switches the connection destination of the fuse element to the FETs, and provides an instruction to switch the FET on.

Abstract: A control method includes: calculating a correction value after a predetermined process is executed; and controlling a control target based on an output value of at least one of a real sensor and a virtual sensor during execution of the predetermined process. The calculating includes correcting an output value of the virtual sensor. The controlling includes: controlling the control target based on an output value of the real sensor while monitoring a failure of the real sensor; correcting an output value of the virtual sensor with the correction value when the real sensor fails; and switching from a control based on the output value of the real sensor to a control based on the output value of the virtual sensor after the correcting the output value of the virtual sensor.

Abstract: The present invention relates to electromechanical device status monitoring and equipment protection applications for industrial automation, HVAC, and other implementations; and, more particularly, to the use of current sensing devices to detect loss-of-flow conditions. Presently described embodiments can comprise simplified, compact current sensing devices that can be economical to build, inventory, distribute, and purchase. Present embodiments can easily be calibrated and/or set by hand prior to installation, and they can be configured for automatically offering proof-of-flow detection based, at least in part, on the initially provided setting.

Abstract: A treatment system for performing a treatment on a patient may include a treatment fluid preparation device having a pump connected by a fluid channel to a reservoir of a source fluid, the pump conveying the source fluid from the reservoir, through a filter, and combining the source fluid with a concentrate by pumping the source fluid with the concentrate to form a treatment fluid in a batch container. The treatment fluid preparation device may have a controller that controls a heater, the pump, and a memory. The controller starts the heater to warm the treatment fluid in the batch container at a time that is responsive to the treatment time stored in the memory. The controller also detects a pressure property of the filter to determine its integrity and outputs an indication of a failed batch if the pressure property indicates the integrity of the filter is insufficient.

Abstract: Embodiments include systems and methods for heating materials, including heating materials for cooking and soldering. A representative system and method for cooking food includes passing electric current through the food, sensing a characteristic of the food, and modulating the electric current in response to the characteristic of the food to achieve a selected internal temperature of the food. The system and method can include searing the food with hot oil or photons directed at the surface of the food. A representative system and method for heating a material includes modulating a plurality of semiconductor light sources to emit photons toward the material, measuring a temperature of the material, and modulating the plurality of semiconductor light sources in response to the temperature of the material. The material can include solder and the method can include heating solder in a reflow soldering process.

Abstract: A semiconductor wafer is heated by a flash of light emitted from a flash lamp after being preheated by a halogen lamp. Temperature of the semiconductor wafer immediately before the flash of light is emitted is measured by a lower radiation thermometer. At the time of irradiation with a flash of light, an upper radiation thermometer measures temperature increase of a front surface of the semiconductor wafer. Front surface temperature of the semiconductor wafer is calculated by adding the temperature increase of the front surface of the semiconductor wafer at the time of irradiation with a flash of light measured by the upper radiation thermometer to the back surface temperature of the semiconductor wafer measured by the lower radiation thermometer.

Abstract: An image forming apparatus includes an AC input portion to which AC power is to be supplied from a commercial power source, an image forming unit configured to form an image on a recording material, a fixing device including a first fixing heater and a second fixing heater which are configured to generate heat, the fixing device being configured to heat the image on the recording material by using the first fixing heater and the second fixing heater to fix the image to the recording material, a first relay configured to be switched between a first state in which electric connection is established and a second state in which electric connection is not established, and a second relay configured to be switched between a third state in which electric connection is established and a fourth state in which electric connection is not established.

Abstract: Apparatus for use in preparing heterostructures having a reduced concentration of defects including apparatus for stressing semiconductor substrates to allow them to conform to a crystal having a different crystal lattice constant.

Abstract: A control system includes an electric heater disposed within an exhaust fluid flow pathway, and a control device for receiving at least one input selected from the group consisting of temperature readings along the exhaust fluid flow pathway, alternator power/current/voltage, battery power/current/voltage/state of charge, IAT and EAT profiles, mass flow rate of an exhaust fluid flow, NH3 slip, TCR characteristics of the heater, alternator speed, engine speed, state of aging of an aftertreatment component, state of aging of engine, aging degradation characteristics, a dosing rate and a temperature of DEF, NH3 storage condition of aftertreatment system, an ambient temperature, and combinations thereof. The control device modulates power to the heater based on the at least one input such that the heater provides different power output as a function of the at least one input and a continuously variable power output during operation of the exhaust system.

Abstract: A phase-change memory cell is formed by a heater, a crystalline layer disposed above the heater, and an insulating region surrounding sidewalls of the crystalline layer. The phase-change memory cell supports programming with a least three distinct data levels based on a selective amorphization of the crystalline layer.

Abstract: The present invention relates to a dummy load circuit for a single live wire switch. This includes: a switch circuit—at least a first resistor and a switch are connected in the switch circuit, wherein the first resistor is connected to the switch, such that the first resistor is connected to the dummy load circuit through the switch; and a switch control circuit—the switch control circuit at least includes a switch control device, wherein the switch control device is connected to the switch to facilitate power-on/off control. The invention also relates to an electrical load with a dummy load circuit.

Abstract: In an embodiment, a circuit includes: an error amplifier; a temperature sensor, wherein the temperature sensor is coupled to the error amplifier; a discrete time controller coupled to the error amplifier, wherein the discrete time controller comprises digital circuitry; a multiple bits quantizer coupled to the discrete time controller, wherein the multiple bits quantizer produces a digital code output; and a heating array coupled to the multiple bits quantizer, wherein the heating array is configured to generate heat based on the digital code output.

Abstract: A method, system, and computer program product, include recording high-frequency wave data of local arid adjacent fault curves of a power grid to compare the high-frequency wave data with historical fault data to detect an actual fault region in the power grid, the power grid having a plurality of sensors distributed in the power grid, each sensor being upstream of one adjacent sensor and downstream of an other adjacent sensor.

Abstract: The method includes the step of passing an electric current through at least one wire that is situated between a carcass of a tire casing and a tread. The method also includes the step of calculating a value of a temperature of the wire as a function of a relative value of the current. The method proceeds with the step of controlling the current as a function of the temperature value calculated.

Abstract: An imaging system for a high-heat cooking appliance, including a camera system including an optical sensor, a lens, and a set of light emitters; and a camera cooling mechanism thermally connected to the camera system.

Abstract: A surgical cartridge includes an inner plate; and an outer plate arranged approximately parallel to the inner plate. The flow paths between the inner plate and the outer plate are arranged to form an irrigation flow path for directing fluid towards the surgical site via an irrigation connection and an aspiration flow path for directing fluid away from the surgical site via an aspiration connection. The inner plate includes membranes adapted for cooperation with plungers and/or valves of a membrane pump. The membranes include a main membrane, at least two valve membranes and an auxiliary membrane adapted to cooperate with a main membrane plunger, valve and an auxiliary membrane plunger of the pump, respectively.

Abstract: A method for controlling flow in a heating, ventilation, and air conditioning (HVAC) system that imposes an upper limit on the flow of fluid through a heating or cooling coil. Imposing this limit on the flow rate ensures that a temperature change across the coil remains above a minimum threshold and can significantly reduce energy waste. The method includes receiving a first temperature measurement associated with an inlet of the coil, receiving a second temperature measurement associated with an outlet of the coil, and receiving a flow measurement associated with the valve, applying the first temperature measurement, the second temperature measurement, and the flow measurement as input to a model, determining a maximum flow rate that ensures that a difference between the first temperature measurement and the second temperature measurement is above a threshold using the model, and operating the valve in accordance with the maximum flow rate.

Abstract: A method and system are provided or determining a fuel or gas type input into a fuel system or a voltage input into an electrical system of a cooking appliance. For instance, the cooking appliance may be a cooktop appliance or an oven appliance. Particularly, a calibration cycle may be performed in which the heating rate of an object or air at or within the cooking appliance is determined. Based on the determined heating rate, the input may be classified. That is, based on the heating rate, the gas type or input voltage into the cooking appliance may be determined. Further, based on the classified input, the settings of the cooking appliance may be selected for optimal cooking performance.

Abstract: Described is an apparatus for preparing baby formula using a liquid concentrate solution. The apparatus includes a housing with a cavity for receiving and holding a container liquid concentrate solution. A motor is attached with the housing for forcing liquid concentrate solution from the container and into a mixing chamber. A pump and a water tank are also included. A spray head is attached with the housing. The spray head includes a plurality of spray jets in fluid connection with the pump for receiving water from the water tank and dispensing water from the spray jets into the mixing chamber. Finally, the mixing chamber receives the liquid concentrate solution and water, such that when the water and the liquid concentrate solution are introduced into the mixing chamber, the water and liquid concentrate solution mix into a baby formula and are dispensed from an outlet in the mixing chamber.

Abstract: The present disclosure relates to electronic inhalation devices, namely electronic cigarettes and other vaping devices with superior performance and user control over device variables. In some instances, the present device is configured to properly interpret the attached atomizer's electrical resistance and subsequently calibrate the proper electrical output. This prevents the device from overheating the coil and producing temperatures that will degrade the expected liquids. Further, the user may be able to input a code for the corresponding “flash points” of the intended liquid to determine the optimum output for both delivery of compounds formulated and also for the proper temperature range of the device. In other embodiments, the device is configured to interface with an electronic device such as a smart phone.

Abstract: A fluid heater includes a heating circuit, a temperature monitoring circuit, a controller, and an overheat sensing element. The controller is disposed in a control unit and is in circuit communication with a temperature gauge and a power supply switch, the controller being configured to operate the power supply switch in response to feedback from the temperature gauge to maintain the heater at a setpoint temperature. The overheat sensing element is disposed in a heater housing proximate to a thermal fuse and is in circuit communication with the controller to provide an indication to the controller when the overheat sensing element reaches an overheat temperature lower than the critical temperature. The controller is configured to operate the power supply switch to reduce or shut off power to the heating element in response to receiving the indication that the overheat sensing element has reached the overheat temperature.

Abstract: Described embodiments include apparatus for use with a catheter. The apparatus includes a sheath configured for insertion into a body of a subject, and a sensor, coupled to the sheath, configured to detect an electric current passing through the catheter, when the catheter passes through the sheath and into the body of the subject. Other embodiments are also described.

Abstract: A power supply includes a casing; an AC-to-DC converter; an inverter electrically coupled to the AC-to-DC converter; a transformer having a primary side and a secondary side, wherein the inverter is electrically coupled to the primary side of the transformer; an output rectifier electrically coupled to the secondary side of the transformer; a fan, disposed in the casing and configured to remove heat from the casing generated by the AC-to-DC converter, the inverter and the output rectifier; and a fan controller configured to control when the fan is operational, wherein the fan controller is configured to execute a state machine that is configured to change states based at least on a dynamically adjustable counter.

Abstract: In a method for controlling engine power during charge depleting (CD) mode heating of a plug-in hybrid electric vehicle (PHEV), the engine power is controlled according to an amount of heat of an engine required for heating determined using a level of an air-conditioning blower at a point in time at which an operation of the engine starts, an outdoor air temperature, and a coolant temperature, if a full automatic temperature controller (FATC) operates the engine for heating when the vehicle is driven in a CD mode.

Abstract: Disclosed is a mesh heating system including: two or more electrodes configured to supply a current to the wire mesh heating element; a mesh heating element comprising filaments disposed between the two or more electrodes; and a tensioner to maintain the wire mesh heating element at tension along an axis of tension as the wire mesh heating element is heated, wherein some of the filaments of the mesh heating element are disposed to intersect the axis of tension at a non-orthogonal angle.

Abstract: A passive cooling system for an electric motor drive circuit in a bathing installation, including a section of hollow pipe made of a thermally conductive tubing material, the pipe configured to form part of a water recirculation path of the bathing installation. An adapter structure has a conformal surface configured for attachment to an outer surface of the pipe and a circuit contacting surface for attachment to the motor drive circuit, the adapter structure fabricated of a thermally conductive adapter material. The adapter structure provides a thermal conductive path between the motor drive circuit and the pipe section, configured to pass heat generated by the circuitry to the pipe section and into spa water flowing through the water recirculation path, to cool the circuitry and warm the spa water.

Abstract: A temperature control system for appliances, such as an electric grill, air fryer, vacuum blender, convection oven, induction cooker (e.g., wok), coffeemaker, etc. The control system comprises digital circuitry for controlling temperature of the appliance, and includes a first safety component in the circuitry for stopping the heating function at a threshold parameter, such as a maximum temperature, and a second safety component in the circuitry for stopping the heating function at a second threshold temperature if the first safety component fails at the first threshold temperature. The first and second safety components, preferably switches or fuses, are connected in series to establish a redundant safety mechanism.

Abstract: The slow cooker with heating and cooling functions comprises a base with both heating and cooling functions, a crock, and a lid. Food may be placed into the crock and covered with the lid. The crock may then be placed into the base, which may be programmed to heat and/or cool the food in the crock. The base further comprises a controller that determines when, how long, and to what extent the heat or cooling should be applied to the crock. The controller may display operational status and accept operational input from a touch sensitive display on the front of the base. The controller may communicate wirelessly with a smart device so that operational status and operational input that are accessible on the front of the base may be accessed from the smart device.

Abstract: A cooking equipment running method and device are provided, and relate to the technical field of terminals. The method includes: a current running mode is acquired if it is detected that a water level of cooking equipment exceeds a preset water level during a running process of the cooking equipment; a target running mode is determined according to the current running mode, heating power in the target running mode being less than heating power in the current running mode; and the current running mode is switched to the target running mode.

Abstract: A radio frequency (RF) heating and defrosting apparatus may include an electrode which, when supplied with RF signal energy, may responsively radiate electromagnetic energy into a cavity of the RF heating and defrosting apparatus. This radiated electromagnetic energy may cause a thermal increase of a load in the cavity. A capacitor may be formed from a portion of the electrode and a conductive plate disposed adjacent to the electrode. The conductive plate may be coupled to a ground reference structure. Dielectric material(s) having a low dielectric constant may be disposed directly between the electrode and the conductive plate.

Abstract: It is advantageous to switch an active element with a background element. By using a switching mechanism, a background element can be made active while the application remains active. That is, the application does not need to be taken offline to switch the active element with a previously loaded background element. Single input/single output (SISO) relationships are defined for background elements and an active element which provides one or many functions and an active element which provides one or many functions between one input variable and one output variable. The switching mechanism acts on a given SISO relationship to determine the background element to use to replace the active element.

Abstract: A control system of an exhaust sensor controlling an exhaust sensor comprises a heater control part controlling a heater and a temperature estimating part estimating a temperature of an exhaust pipe around the exhaust sensor. The heater control part sets the target temperature to a first target temperature after startup of the internal combustion engine and until the estimated temperature of the exhaust pipe reaches a first exhaust pipe temperature, sets the target temperature to a second target temperature from when the estimated temperature of the exhaust pipe reaches the first exhaust pipe temperature to when it reaches a second exhaust pipe temperature, and sets the target temperature to an operating temperature of the electrochemical cell when the estimated temperature of the exhaust pipe reaches the second exhaust pipe temperature.

Abstract: The present invention generally relates to a system and method for high accuracy temperature control of an oven used to operate an electronic device, sensor, or resonator at a fixed temperature. The fixed temperature operation may result in high stability and operation accuracy of the devices across varying environment temperature conditions. Specifically, the present invention relates to systems and methods that enable realizing, sensing, and controlling the temperature of an ovenized device with high temperature control, accuracy, relaxed temperature sense, and control electronics requirements.

Abstract: A building management system includes a controller configured to control building equipment by providing a control input to the building equipment for each of the plurality of time steps and generate a set of training data for a system model for the building. The training data includes input training data and output training data for each of the plurality of time steps. The controller is further configured to perform a system identification process to identify parameters of the system model. The system identification process includes predicting, for each time step, a predicted value for one or more of the output variables for each of a plurality of subsequent time steps, generating a prediction error function by comparing the output training data to the predicted values, and optimizing the prediction error function to determine values for the parameters of the system model that minimize the prediction error function.

Abstract: A semiconductor substrate support for supporting a semiconductor substrate in a plasma processing chamber includes a multi-plane heater such as a heater array comprising thermal control elements operable to tune a spatial temperature profile on the semiconductor substrate. The multi-plane heater includes at least one pair of vertically offset heating elements connected in series or parallel to control heating output in a heating zone on the substrate support. The thermal control elements can be powered by two or more power supply lines and two or more power return lines wherein each power supply line is connected to at least two of the heater zones and each power return line is connected to at least two of the heater zones.

Abstract: A high-efficiency modulating gas furnace (herein ‘gas furnace’) includes a furnace controller. The gas furnace further includes a gas valve and at least one pressure switch that is coupled to the furnace controller. The electrical contacts of the at least one pressure switch are removed from a series electrical circuit with the gas valve such that the gas furnace operates without de-energizing the gas valve as soon as the electrical contacts of the at least one pressure switch are opened. Further, the furnace controller operates the induced draft blower at or close to a lowest RPM at which the electrical contacts of the at least one pressure switch can be kept closed, which is between a make point RPM at which the electrical contacts of the at least one pressure switch close and a break point RPM at which the electrical contacts of the at least one pressure switch open.

Abstract: A method of controlling a heating element within a steering wheel of a vehicle comprising: presenting a vehicle comprising a steering wheel including a heating element, a controller in communication with the heating element, the controller including a Pre-established Predictive Activation Model setting forth rules governing activation of the heating element as a function of data relating to Certain Identifiable Conditions, and a user interface configured to allow the heating element to be manually activated or deactivated; collecting data relating to the Certain Identifiable Conditions; determining, by comparing the collected data to the rules of the Pre-established Predictive Activation Model, whether the collected data satisfies the rules of the Pre-established Predictive Activation Model so as to initially automatically activate the heating element; and automatically activating the heating element.

Abstract: A hot water supply method according to one embodiment of the present invention comprises the steps of: measuring a temperature of water flowing into an water inlet part; turning on a first heater and a second heater if a target temperature is a standard temperature or higher; adjusting a degree of opening and closing of a flow rate adjusting valve on the basis of a difference between the target temperature and the temperature of water flowing into the water inlet part; measuring a temperature of water discharged to a water outlet part; and readjusting the degree of opening and closing of the flow rate adjusting valve on the basis of a difference between the target temperature and the temperature of water discharged to the water outlet part.

Abstract: A water heater monitoring and notification method includes determining, by a controller of a water heater system, a deviation of a duration of a pre-purge operation from a pre-purge duration average value. The method further includes determining, by the controller of the water heater system, a deviation of a flame current from a flame current average value and determining, by the controller of the water heater system, a deviation of a pulse-width-modulation (PWM) parameter from a PWM parameter average value. The method also includes providing a notification related to a combustion system of the water heater system based on at least the deviation of the duration of the pre-purge operation from the pre-purge duration average value, the deviation of the flame current from the flame current average value, and the deviation of the PWM parameter from the PWM parameter average value.

Abstract: Electric apparatus for cooking and/or heating food includes a chamber to receive food, electric heating elements associated with said chamber, at least one temperature sensor to measure a temperature in the chamber, and a temperature control device provided with a control and power supply unit configured to receive the temperature measured by the sensor and compare it with a desired temperature in a central zone of the chamber. The temperature control device may also comprise at least one estimator filter configured to receive at entrance: the temperature detected, the actual power supplied to the electric heating elements by said control unit and the data relating to previous temperature estimations and able to supply at exit an estimated temperature, wherein said control unit is configured to use the estimated temperature transmitted by the estimator filter to establish the correct mean power to be supplied by the electric heating elements.

Abstract: A thin-film device for generating a blackbody spectrum is disclosed. The device includes first layer configured to generate heat in response to an applied voltage and a second layer configured to generate the blackbody radiation spectrum in response to the heat from the first layer. A thermocouple is disposed between the first layer and the second layer for measuring a temperature at the second layer. The thermocouple measures temperature at the second layer in order to control temperature at the second layer. The thermocouple can be a copper-carbon nanotube thermocouple.

Abstract: A thin-film device for generating a blackbody spectrum is disclosed. The device includes first layer configured to generate heat in response to an applied voltage and a second layer configured to generate the blackbody radiation spectrum in response to the heat from the first layer. A thermocouple is disposed between the first layer and the second layer for measuring a temperature at the second layer. The thermocouple measures temperature at the second layer in order to control temperature at the second layer. The thermocouple can be a copper-carbon nanotube thermocouple.

Abstract: An oven controlled crystal oscillator consisting of heater-embedded ceramic package includes a substrate, a crystal package, a crystal blank, a metal lid, a first IC chip, and a cover lid. The crystal package is mounted on the substrate, and a central bottom of the crystal package is provided with the first IC chip. The crystal blank is mounted in the crystal package and sealed by the metal lid. The crystal package has an embedded heater layer establishing a symmetric thermal field with respect to the first IC chip and the crystal blank. Alternatively, a heater-embedded ceramic carrier substrate is arranged between the first IC chip and the crystal blank to establish a symmetric thermal field with respect to the first IC chip and the crystal blank. The cover lid is combined with the substrate to cover the crystal package and the metal lid.

Abstract: A vehicle includes: a battery charger configured to be able to perform external charging that charges a battery using electric power from an external power source; and a warming device configured to warm the battery, the warming device being connected to an electric power line connected to the battery. When temperature of the battery is less than a second prescribed temperature that is lower than a first prescribed temperature during execution of charging control that controls the battery charger to perform the external charging, warming control that controls the warming device to warm the battery is executed, and when the temperature of the battery is equal to or more than the second prescribed temperature, execution of the warming control is suppressed.

Abstract: Techniques are provided for power optimization of home automation system devices (e.g., battery-powered devices). In one example embodiment, the power optimization is based on service states for a room associated with the device. A service state is determined for each of one or more services available in the room. The device is maintained in a low-power inactive state while there are no active services in the room. In response to at least one service being activated, the device transitions from the inactive state to a full-power in-use state. Such transition is performed preemptively, absent any current attempt to use the device by a user or another device. In response to expiration of a timer since a last use of the device or the transition to the in-use state was made and no actual use occurred, the device exits the in-use state and may eventually return to the inactive state.

Abstract: Automatic coffee machines have very low thermal efficiency because they have to heat a considerable thermal mass, constituted by the heater 3) appearing in FIG. 1, which has a weight generally ranging between 0.5 and 1 Kg of metal, typically consisting of aluminum. Said mass is used to stabilize the temperature of the water to be injected in the blend of coffee. In this configuration, 90% or more of the thermal energy is wasted. The energy saving coffee machine, the subject matter of the present invention, is instead constructed with a heater 3), appearing in FIG. 4, that has a thermal mass much lower than the mass of the liquid to be heated, and is typically constructed with metal tube 30), as shown in FIG. 4, weighing a few grams. The heating current 41) in FIG. 4 flows directly on said tube, heating it together with the water contained therein, while a very rapid temperature control circuit makes it possible to maintain a constant temperature of the water flowing through the heater 3) shown in FIG. 4.

Abstract: A drug delivery apparatus provides autonomous variable rate delivery of a substance. In some embodiments, the delivery apparatus may be programmable. In some embodiments, the delivery apparatus may be disposable. Optionally the rate of delivery may be dependent on a temperature of a component of the apparatus. Optionally, there may be a time delay between activation of the apparatus and delivery power of the substance.

Abstract: The control system of an internal combustion engine controls an internal combustion engine comprising an exhaust sensor. The control system comprises a motoring device driving rotation of a crankshaft of the internal combustion engine, a motoring control part configured to control the motoring device, a heater control part configured to control supply of electric power to the heater, and a temperature estimating part configured to estimate a temperature of the sensor element. The motoring control part is configured to drive the motoring device for a predetermined time when the temperature of the sensor element estimated by the temperature estimating part is outside a predetermined cracked element temperature region while the heater control part is supplying electric power to the heater, and stop driving the motoring device when the temperature of the sensor element is within the cracked element temperature region.

Abstract: An oven controlled crystal oscillator consisting of heater-embedded ceramic package includes a substrate, a crystal package, a crystal blank, a metal lid, a first IC chip, and a cover lid. The crystal package is mounted on the substrate, and a central bottom of the crystal package is provided with the first IC chip. The crystal blank is mounted in the crystal package and sealed by the metal lid. The crystal package has an embedded heater layer establishing a symmetric thermal field with respect to the first IC chip and the crystal blank. Alternatively, a heater-embedded ceramic carrier substrate is arranged between the first IC chip and the crystal blank to establish a symmetric thermal field with respect to the first IC chip and the crystal blank. The cover lid is combined with the substrate to cover the crystal package and the metal lid.

Abstract: A method for controlling the temperature of glow plugs of a combustion engine is described, wherein all glow plugs are heated up for an engine start by the input of electrical energy according to a profile which is uniformly specified for all glow plugs of the engine, a change in resistance ?R is ascertained for each of the glow plugs for at least one specified time span, and a target resistance value is calculated for each glow plug from the associated change in resistance ?R, this value being expected for the glow plug when it has reached its target temperature, and the target resistance value is used to control the temperature of the glow plug to the target temperature.