Abstract: At least one embodiment of the invention relates to a protective circuit for protection of an appliance, in particular of an electric motor, against thermal overloading. In at least one embodiment, the protective circuit includes a first and a second terminal for connecting a temperature detection element; a detection unit for detecting whether a resistance value of the temperature detector element which is connected between the first and the second terminals, is in a first or a second resistance range; a short-circuit detector for identifying whether there is a short circuit between the first and the second terminals; signaling outputs for emitting signal messages to an evaluation unit when the detected resistance value is in the second resistance range and/or when a short circuit has been identified by the short-circuit detector; and a third terminal, which is connected to the second terminal via a predetermined resistance.

Abstract: An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power input, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.

Abstract: A circuit for controlling a rotation speed of a fan of an electronic device according to a temperature of the electronic device. The circuit senses the temperature of the electronic device, and outputs a voltage changing with the sensed temperature. The rotation speed of the fan changes with the voltage. The circuit slows the rotation speed of the fan down when the sensed temperature of the electronic device is decreased.

Abstract: A method for controlling a motor current supplied to an electric motor by using an inverter device is provided. The inverter device includes an inverter circuit and a capacitor connected to an input of the inverter circuit. The method includes controlling the inverter circuit in such a manner as to supply an alternating electric current to the electric motor after the temperature of the capacitor reaches a temperature at which a maximum acceptable motor current value becomes greater than or equal to a value at which the torque necessary for starting the electric motor is produced.

Abstract: A control device for controlling a recovery from a locking of a motor includes: a switching unit which supplies a motor current from a current supplying unit to the motor; and a driving control unit which supplies a PWM control signal to the switching unit to control a driving of the switching unit. The driving control unit supplies the PWM control signal with a low duty ratio lower than a regular duty ratio to the switching unit when the locking of the motor is detected depending on a variation in temperature of the switching unit. The driving control unit supplies the PWM control signal with the regular duty ratio to the switching unit when a cancel of the locking of the motor is detected depending on a variation in inter-terminal voltage of the motor.

Abstract: In order to prevent a short circuit of top and bottom arms of a motor driving IC when noise is added to six control signals for controlling six switching elements, there is provided a semiconductor device for driving a motor, being sealed with resin as one package and comprising: six switching elements for driving a three-phase motor; three output terminals for outputting voltages to the three-phase motor; at least one driving circuit for driving the six switching elements; three control signal input terminals; and a function) of generating six control signals for control of the six switching elements based on three control signals inputted through the three control signal input terminals.

Abstract: A heat dissipation system for an electronic device comprises a base, a fan, a pulse width modulation speed control circuit controlling the speed of the fan, a converter outputting a voltage signal, a selection switch connected to the motor, and a control element provided on the base, connected to the switch and to the converter. When the control element is operated, the switch selectively enables the motor be connected to the output of the pulse width modulation speed control circuit or to the output of the converter, and when the motor is electrically connected to the converter, the control element can modify the output voltage of the converter.

Abstract: A protecting device of a fan system includes at least one first switch element and at least one control unit. The first switch element receives a first input signal. The control unit is electrically connected with the first switch element, receives the first input signal, and controls the first switch element to turn on or turn off according to the first input signal. The control unit stops outputting the first input signal when the first switch element turns on. The control unit outputs the first input signal when the first switch element turns off, so that a fan of the fan system can be driven by the first input signal.

Abstract: Provided is a motor controller and method of controlling a motor with an improved maximum junction temperature rating. In accordance with one aspect of the present invention, a motor is controlled by varying a common mode voltage duty ratio for a plurality of solid state switching devices in a power inverter, generating drive signals for the solid state switching devices based at least in part upon the common mode voltage duty ratio, and changing states of the solid state switching devices based upon the drive signals.

Abstract: This invention patent is a utility type of car fan controller. The controller has a housing and inside the housing is a circuit. The housing has a top cover forming a cavity and flat bottom plate. The circuit has a circuit board and an adjustment device with other electronic components. The circuit board has a socket connector and a wire harness connector. The top cover has socket connector aligned with socket connector opening. The top cover also has a wire harness connector aligned to wire harness connector socket. The modular practical new type of invention design facilitates faster assembly and more convenient flexible use.

Abstract: A heat dissipation system includes at least one fan, at least two controllers, a signal generator, and a signal converter. The controllers are electrically connected to the fan and generate an enable signal according to a feedback signal of the fan. The signal generator is electrically connected to the controllers and generates a control signal according to the enable signal. The signal converter is electrically connected to the signal generator and the fan, converts the control signal to a drive signal to the fan, thereby controlling rotation speed of the fan.

Abstract: In the case of an electromotive auxiliary drive for vehicles, particularly for windscreen wiper drives or adjustment drives for vehicle elements with a secondary transmission for the electromotor, with at least one magnetic sensor, which acts in conjunction with a signal transmitter or permanent magnet arrangement formed of at least one permanent magnet and rotating with a drive shaft or a gear wheel in order to record the angle position and/or modification of the angle position of the rotation of the shaft or the gear wheel, the permanent magnet arrangement is arranged on the front side on a shaft end bedded in a bearing arrangement or on a drive element bedded in the bearing arrangement and arranged on the shaft. The at least one magnetic sensor is arranged opposite the permanent magnet arrangement in the direction of the shaft axis within the bearing arrangement.

Abstract: An apparatus for detecting a type of fan and controlling the fan, the fan providing during operation a tachometer signal indicating a speed of the fan, the apparatus includes: a direct current (DC) generator for coupling to the fan and configured to provide a first voltage to the fan; a resistor for providing, while the DC generator provides the first voltage, a sensed voltage relating to the type of the fan, wherein the resistor is connected to a reference voltage and for coupling to a pulse-width modulation (PWM) control terminal of the fan; an input judgment component coupled to the resistor to receive the sensed voltage, the input judgment component being configured to determine whether the fan is a 4-wire PWM fan with an internal pull-up resistor based on the sensed voltage and to provide a judgment signal indicating the determination; a PWM generator coupled to the input judgment component to receive the judgment signal, the PWM generator being configured to provide to the fan a PWM control signal to co

Abstract: An electric motor controller for a vehicle has a voltage detecting section for detecting the voltage of a filter capacitor inserted on a direct current side of an inverter device including a semiconductor element for large electric power; an electric current detecting section for detecting an output electric current of the inverter device; and a temperature detecting section arranged in a cooling means of the semiconductor element for large electric power. Loss generated by a switching operation of the semiconductor element for large electric power is sequentially calculated by outputs of the detecting sections. Excessive temperature is detected when junction temperature of the large electric power semiconductor element calculated by this loss reaches an allowable temperature.

Abstract: This invention provides a motor control method which comprises the steps of operating a motor at a fanless operation mode when a ambient temperature is lower than a lower temperature, operating the motor at a silent operation mode when the ambient temperature is higher than the lower temperature and lower than a higher temperature, and operating the motor at a cooling operation mode when the ambient temperature is higher than the higher temperature. When the motor operates at the fanless operation mode, the rotation speed of the motor is zero rpm. When the motor operates at the silent operation mode, the motor operates at a constant rotation speed. When the ambient temperature is higher than the higher temperature, the rotation speed of the motor is a linear function of the temperature and varies between the higher temperature and a maximum temperature corresponding to the full rotation speed of the motor.

Abstract: A switch-type power converter comprising an PET switch operating in a variable duty cycle mode under the control of a Unitrode 3846 integrated circuit controller. Indications of excess input voltage and reverse battery connections are provided by circuits including an element which permanently changes state. A cooling fan mounted on a finned heat sink is operated in a variable speed mode. A single thermistor sensor provides inputs to both the fan speed control and a thermal shutdown circuit connected to shut down the gate drives to the FET switch in the event of a high temperature condition. Another shutdown function is provided in response to an input overvoltage condition by way of an operational amplifier. The converter uses foldback for short circuit protection and is compatible with microprocessor units to selectively provide multiple output voltage levels.

Abstract: A self-magnetizing motor incorporates a control circuit that starts the motor, controls a magnetizing unit, and then operates the motor. The control circuit can include relay, such as a bi-directional conductive power semiconductor device, and one or more PTC (Positive Temperature Coefficient) switches. This control circuit eliminates the need for a separate controller and the implementation costs can be reduced.

Abstract: Automated control is provided of rotational velocity of an air-moving device cooling an electronics subsystem of an electronics rack. The automated control includes: automatically responding to a failure event associated with the electronics subsystem of the rack by setting rotational velocity of the air-moving device to a first upper limit (RPM1) above a normal operating limit; sensing motor temperature of a motor of the air-moving device; automatically increasing rotational velocity of the air-moving device to a second upper limit (RPM2) if the sensed motor temperature is below a first predefined temperature threshold (T1), wherein RPM2>RPM 1; maintaining rotational velocity of the air-moving device at the second upper limit while the sensed motor temperature is below a second predefined temperature threshold (T2), wherein T2>T1; and returning to normal operating rotational velocity of the air-moving device subsequent to servicing of the electronics rack responsive to the event.

Abstract: Kinematic control of an electronic positioner and its associated actuator is effected through a control algorithm that delivers energy to the actuator based on observed motion produced by a previous delivery of energy. The algorithm achieves control based on a desired or user-specified resolution. Electronic braking between energy delivery intervals improves the speed at which the desired position is achieved. Temperature of the force producing mechanism is determined, as by monitoring energy consumed, and used to control how power is delivered to the actuator.

Abstract: An electronic apparatus includes: a timer member that clocks time on the basis of the power supplied from a power source. A power supply member supplies the power to an electric motor of the electronic apparatus and to the timer member from the power source and interrupts the power supply thereto. A heat storage calculating member calculates heat storage of the electric motor and calculates heat storage of the electric motor after stop of the drive on the basis of the time clocked by the timer member. A controller controls the electric motor and controls the power supply member by initiating power-on and power-off operations. This is performed so as to, maintain the power supply to the timer member and the heat storage calculating member during a predetermined time, even after the power-off operation of the operation member.

Abstract: A generator-motor apparatus includes a control circuit, an alternator, electrode plates, and switching devices. The electrodes plates have a substantial horseshoe shape, and are provided on an end surface of the alternator so as to surround a rotating shaft of the alternator. Each of the switching devices is formed by sandwiching a MOS transistor between two electrodes, and has a can structure for sealing the internal space of the switching device using a resin. The switching devices are directly attached to the electrode plate by means of soldering, and the switching devices are directly attached to the electrode plate by means of soldering. The control circuit controls the switching devices. The switching devices drive the alternator as an electric motor or an electric power generator.

Abstract: When a fan drive current has become excessive, a fan drive device intercepts that current, waits for just a fixed time period T1, and thereafter flows that current for a second time. The fan power supply current flowed to the fan drive device is detected by a shunt resistor R. The value of the fan power supply current detected by the shunt resistor R is inputted to a controller, and the cause of any abnormality of the fan is decided upon by this controller, based upon the magnitude of the above described fan power supply current and the time period over which it has continued.

Abstract: According to an example embodiment, a method is provided for limiting an operational temperature of a motor. The method includes generating a maximum allowable current I*S(max) for a motor based on a temperature difference between a temperature reference T* of a power inverter module and a semiconductor device temperature T of the power inverter module. The method further includes generating a maximum allowable torque T*e(max) based on the maximum allowable current I*S(max) and a maximum allowable flux ?*S(max), and using the maximum allowable torque T*e(max) to limit the torque command T*e in order to suppress the semiconductor device temperature T to below the temperature reference T*.

Abstract: An apparatus, system, and method are disclosed for controlling fan speed in a power supply. The apparatus measures input power to the power supply and measures the output power provided by the power supply over an interval. The apparatus determines values for the input power and output power and, using the two, determines how much power has been dissipated in the power supply. Power dissipation values are associated with particular fan speeds, and the apparatus adjusts the speed of the fan in the power supply based on how much power was dissipated during the interval. Increasing levels of power dissipation increases the fan speed, and decreasing levels of power dissipation decrease the fan speed.

Abstract: Presented in an apparatus for controlling a brushless DC motor with a permanent magnet arranged on a rotor and a stator with windings. The apparatus includes an observer that is adapted to determine an estimated temperature of the permanent magnet as a function of the temperature of the windings, and determine at least one actuating signal for controlling the DC motor as a function of the estimated temperature of the permanent magnet.

Abstract: A fan driving circuit includes a temperature sensor, a super input and output (SIO) chip, an integrator, a feedback circuit, and a control circuit. The temperature sensor is configured for measuring a temperature of a computer component and outputting a temperature signal according to the measured temperature. The SIO chip is configured for converting the temperature signal into a digital pulse width modulation (PWM) signal. The integrator is configured for converting the PWM signal into an analog signal. The feedback circuit is configured for processing a driving voltage powering a fan to dissipate heat from the computer component and outputting a feedback signal for to compare with the analog signal. The control circuit is configured for comparing the feedback signal with the analog signal and outputting a new driving voltage to control the speed of the fan.

Abstract: A dynamic braking load analyzer that determines the proper resistance value for a dynamic braking load resistor to be used in combination with a variable frequency drive or servo-drive to accommodate the power dissipated from an induction motor when it is being reduced in speed. The analyzer includes a resistor bank having a plurality of resistors electrically coupled in parallel. Switches are provided between the resistors, and a resistor selector switch determines which resistors are switched into the resistor bank circuit. A heat sensing resistor in the resistor bank measures the heat generated by the resistors and provides a signal that is read by a heat meter. The combination of the temperature measurement and the resistance of the resistors in the circuit gives the proper braking resistance value for the deceleration of the induction motor.

Abstract: Method and arrangement in connection with a motor fed with a frequency converter provided with an intermediate voltage circuit. The method comprises steps of feeding motor voltage to the motor along a motor cable with a frequency converter for controlling the motor, rectifying the voltage of the motor cable and restricting the magnitude of the voltage of the motor cable at the end of the motor cable on the side of the motor with a clipper circuit coupled in parallel with the motor, using the rectified voltage for rotating one or more cooling fans of the motor.

Abstract: An apparatus and method for controlling fan operation in a system having a fan are provided. The apparatus includes a temperature sensor configured to detect at least one internal temperature of the system as a whole or component devices thereof, a power supply configured to convert one or more different input powers into predetermined voltage levels and supply the voltage levels to the fan, and a controller connected to the temperature sensor and the power supply and configured to control operation of the fan, wherein the controller controls fan operation based on a fan control mode selected by a user and the sensed at least one internal temperature.

Abstract: Methods and apparatuses to manage working states of a data processing system. At least one embodiment of the present invention includes a data processing system with one or more sensors (e.g., physical sensors such as tachometer and thermistors, and logical sensors such as CPU load) for fine grain control of one or more components (e.g., processor, fan, hard drive, optical drive) of the system for working conditions that balance various goals (e.g., user preferences, performance, power consumption, thermal constraints, acoustic noise). In one example, the clock frequency and core voltage for a processor are actively managed to balance performance and power consumption (heat generation) without a significant latency. In one example, the speed of a cooling fan is actively managed to balance cooling effort and noise (and/or power consumption).

Abstract: A method for controlling fan speed is disclosed. Firstly, a number of temperature ranges are defined. Each temperature range is associated with a corresponding fan speed. Each two adjacent temperature ranges overlap. The temperature of an electronic system is measured and is compared with the defined temperature ranges to determine whether it enters into a new range. If the measured temperature exceeds any one of the limits of a temperature range associated with the current fan speed, it enters into a new temperature range. The fan speed is adjusted to which is associated with the new entered temperature range. The overlap of each two adjacent temperature ranges covers the fluctuation of the temperature of the electronic system caused solely by the adjustment of fan speed caused by the traversing of the measured temperature between the two adjacent temperature ranges.

Abstract: A device includes a transmitter, at least one temperature sensor; and a controller. The controller is responsive to the at least one temperature sensor indicating that a temperature has risen above a first threshold to control the transmitter to reduce transmit power from a first power level to a second power level, wherein the second power level is a non-zero power level.

Abstract: A method of controlling a DC motor is presented. In a determining action, a thermal power dissipation is determined from a motor input and a motor velocity. In another determining action, a motor temperature is determined based on a thermal model using the thermal power dissipation. In an adjusting action, a usage of the motor is adjusted, taking the motor temperature into account.

Abstract: A movable barrier operator having a motor controller (10) and motor (11) that control selective movement of a movable barrier (12) also has an obstacle detector (14) that utilizes an automatically determined excess force threshold value to permit reliable detection of an obstacle under a wide variety of operational circumstances, including changing physical circumstances, aging components, temperature variations, and motor runtime. In a preferred embodiment, a characteristic force value for the system is frequently updated as a function of actual measured force requirements (and further compensated, pursuant to various embodiments, with respect to other conditions such as temperature and motor runtime). This characteristic force value is then utilized to determine the excess force threshold value.

Abstract: The invention relates to a method for temperature limitation according to the current and/or voltage, for an actuating device (10) associated with an electric motor (M), especially a fan regulator (12) of a motor vehicle, the temperature limitation being carried out according to at least one operating parameter of the motor (M). The invention also relates to a corresponding device (1) and a fan regulator (12).

Abstract: A rotating speed adjustment circuit for a heat dissipation fan includes a first node, a second node, a reception end for receiving a first control signal, a first resistor coupled to a voltage source and the first node, a second resistor coupled to the first node and the second node, a third resistor coupled to the second node and a ground end, a capacitor coupled to the first node and the ground end, a transistor coupled to the reception end, the second node and the ground end, an oscillator for generating an oscillating signal, and a comparator for comparing a signal of the first node and the oscillating signal, so as to output a second control signal to control a rotating speed of the heat dissipation fan.

Abstract: An air movement system including a blower and an external controller operable to receive signals from a sensing device and generate a command based on the received signals. The command includes an address. The system also includes a communication channel coupled to the external controller and configured to communicate the command, and a motor assembly operable to drive the blower. The motor assembly includes a stator and rotor assembly coupled to the blower, and a drive circuit coupled to the stator and rotor assembly. The motor assembly includes a second controller and a memory. The memory includes a set of data having a plurality of addresses and an instruction associated with each address, respectively.

Abstract: A fan with failure detecting function includes a power input terminal, a current limiting resistor, a light emitting diode (LED), and a fan motor. The power input terminal is coupled to the anode of the LED via the current limiting resistor. The cathode of the LED is coupled to one terminal of the fan motor, another terminal of the fan motor is grounded.

Abstract: A system for controlling the fan speed is described. Specifically, one embodiment of the present invention set forth a computing system, which includes a first processing unit including a first sensor, wherein the first processing unit is configured to generate a first pulse-width modulation signal, and a first transmission line further including a first direct current voltage converter configured to convert the first pulse-width modulation signal to a first direct current voltage and a first diode coupled to the first direct current voltage converter, wherein the first diode determines whether the first direct current voltage passes through the first diode. The computing system further includes an amplifier coupled to the first diode, wherein the amplifier is configured to amplify a selected direct current voltage to drive a fan.

Abstract: A disk drive is disclosed including a disk, a head coupled to a distal end of an actuator arm, and a voice coil motor (VCM) operable to rotate the actuator arm about a pivot to actuate the head radially over the disk, wherein the VCM comprises a coil. Control circuitry within the disk drive measures a load resistance of the coil prior to executing a load operation, wherein the load operation moves the actuator arm off a ramp to load the head onto the disk. The load resistance of the coil is then converted into an initial coil temperature estimate.

Abstract: Provided is an electric device capable of encouraging a user to perform maintenance in a forceful manner when the performance such as safety, operation efficiency or the like decreases. In an electric device of the present invention, a control circuit controlling an operation of the actuator includes detecting means for detecting a drive condition value which varies in accordance with deterioration of one or a plurality of components forming the electric device, and output limit means for limiting an output of the actuator in accordance with the drive condition value detected by the detecting means.

Abstract: A power steering apparatus includes an electric motor, a temperature sensor, and a control unit. The electric motor produces an assist steering effort in a steering system. The temperature sensor measures a temperature of a first portion subject to thermal influence of operation of the electric motor. The control unit determines an estimated temperature of a second portion in accordance with a value of a motor current, the second portion being subject to thermal influence of operation of the electric motor. The control unit determines a first upper limit value in accordance with the measured temperature; determines a second upper limit value in accordance with the estimated temperature; limit the motor current to a smaller one of the first and second upper limit values, when determining that the temperature sensor is normal; limit the motor current to the second upper limit value, when determining that the temperature sensor is abnormal.

Abstract: A motor control device includes a motor, a control portion controlling the motor, estimating a heating temperature of the motor on the basis of an electric current value and an energizing time period or a stopping time period of the motor, and restricting an electrification of the motor in a case where the estimated heating temperature becomes equal to or greater than a limit value, and a temperature sensing device for detecting a temperature of a predetermined portion of a vehicle, wherein the control portion estimates an initial temperature of the motor when an engine is started on the basis of a temperature signal outputted from the temperature sensing device and determines the limit value on the basis of the estimated initial temperature.

Abstract: A main power off-delay device for a power supply of a computer system is described, which comprises a control device connected to the outer power supply or disposed on a circuit board of a computer system host. Using the switch electrically coupled to a circuit of said control device and the transmitted signals, main power and standing power are continuously supplied by the power supply when the computer operational system is turned off.

Abstract: A device for driving a single phase motor is provided. The device controls the rotation of the single phase motor according to at least a control signal. The single phase motor driving device includes a control apparatus and a detection apparatus. The control apparatus detects the rotation or stopped rotation of the single phase motor, and outputs a detection signal and at least the control signal. The detection apparatus coupled to the control apparatus generates a first comparison signal and a second comparison signal according to the detection signal, compares the first comparison signal with the second comparison signal to generate a comparison result, and then further outputs a rotation signal or a stopped rotation signal according the comparison result; wherein the control apparatus generates the at least the control signal according the rotation signal and the stopped rotation signal.

Abstract: When it is determined that a battery temperature is lower than a threshold value, an inverter control circuit alternately switches an operation point of an AC motor between an optimum operation point and a motor loss increase point. At the motor loss increase point, an increase in the amplitude of the motor current increases copper loss occurring in the three-phase coil of the AC motor. On the other hand, at the optimum operation point, a reduction in the amplitude of the motor current reduces copper loss. Corresponding to the cyclical increase/reduction in the copper loss, the battery is cyclically charged/discharged by the electric power corresponding to the copper loss. The change in the battery current occurred by the charge/discharge causes the internal resistance to generate heat, whereby the temperature of the battery is increased.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: A system for compensating the characteristics of a fan, applied to a heat-dissipating fan of an electronic device. This system comprises of an analyzing module for analyzing the relation between the duty ratio of pulse width modulation (PWM) and the rotational speed of the fan to generate analyzing data, and a compensating module for generating compensating data basing on the analyzing data and a specific proportion relation between the temperature and the duty ratio of PWM.

Abstract: Thermal variable-operation regulator that regulates the operation of an operating device by progressively limiting the operation of the operating device (24) as a limitation temperature (Tset) increases. The limitation temperature (Tset), based on which the operation of the operating device (24) is limited, is set to a smoothed temperature (Ttmp), obtained by performing a predetermined smoothing process on the detected temperature (Tiny), by a limitation temperature setting means when a change amount (AT) of the detected temperature (Tiny) is equal to or less than a predetermined change amount (Tref). However, when the change amount (AT) of the detected temperature (Tiny) is greater than the predetermined change amount (Tref), the limitation temperature (Tset) is set without using the detected temperature (Tiny).

Abstract: A fan control system includes a power source, a switch control circuit, a switch control signal delivering unit and a fan circuit module. The power source outputs a nominal power, the switch control circuit electrically connects to the power source, the switch control signal delivering unit electrically connects to the switch control circuit and can send a power control signal to the switch control circuit, and the fan circuit module electrically connects to the switch control circuits. In an initial operation state, the nominal power output from the power source can be reduced to a control power sending to the fan circuit module via the switch control circuit to drive at least one fan within the fan circuit module, and then the power control signal controls the control power after the switch control signal delivering unit sends the power control signal to the switch control circuit.