Abstract: Semiconductor switches for high voltage operations are described. The semiconductor switch includes a first DE-NMOS FET including a gate coupled to a node of the switch with its source and drain coupled to input and output nodes, respectively. The switch also includes a second DE-NMOS FET with a drain coupled to the node. A gate of the second DE-NMOS FET is configured to receive a signal enabling or disabling the switch. The switch includes a voltage source (e.g., a voltage-controlled voltage source) coupled to the node, which supplies a first voltage at the node. The first voltage is greater than a second voltage at the input node by a predetermined amount such that the first DE-NMOS FET may operate within a safe operating area while supporting high voltage operations. The switch also includes a current source configured to supply current to the voltage source.

Abstract: There is provided a control device for an electric motor. The control device includes an inverter circuit and a control circuit. In a control cycle of the electric motor, the control cycle includes first to third sections. The control circuit outputs a first modulated wave in accordance with an output of the electric motor and outputs a minimum value or maximum value of a carrier wave as second and third modulated waves in the first section with a peak of first alternate-current voltage, and outputs the second modulated wave in accordance with an output of the electric motor and outputs the minimum value or maximum value of the carrier wave as the first and third modulated waves in the second section with a peak of second alternate-current voltage. The same output is applied in the third section with a peak of third alternate-current voltage.

Abstract: The present invention is a power module for a system for converting a direct electrical power into a three-phase electrical power. The power module according to the invention comprises two inputs (E1, E2), an output (S), two switches (1), two diodes (D), and two capacitors (Cs, Cov) and to a conversion system comprising such a power module.

Abstract: A motor controller is configured to stabilize a motor current. The motor controller is used for driving a motor, where the motor has a motor coil. The motor controller comprises a switch circuit, a control unit, a command unit, a counting unit, a comparing unit, and a phase detecting unit. The switch circuit is used for supplying the motor current to the motor coil. The phase detecting unit generates a phase signal to the control unit, so as to inform the control unit to switch phases. The control unit generates a plurality of control signals to control the switch circuit. The motor controller resets the counting unit based on the phase signal, such that the control signals are synchronized with the phase signal for stabilizing the motor current.

Abstract: A motor control apparatus includes an inverter comprising switching elements, current detection means for detecting a phase current value output from the inverter to each phase of a three-phase AC motor, conversion means for converting the phase current value into a digital AD conversion value, and modulation means for comparing a phase voltage command value based on the AD conversion value from the conversion means with a PWM counter value generated using a timer operating at predetermined cycles to generate a PWM signal and outputting the generated PWM signal to the inverter to thereby switch the switching elements of the inverter and control the three-phase AC motor. The conversion means outputs the AD conversion value acquired by converting the phase current value at a timing when a rectangular width of a rectangular wave of a phase voltage value corresponding to the PWM counter value is long.

Abstract: A control device alternately turns on an upper arm switch and a lower arm switch constituting an inverter on the basis of an operation pattern that is a time-series pattern that defines a switching pattern for each of the upper arm switch and the lower arm switch. The control device detects each of a present pattern that is the operation pattern currently set and a next pattern that is the operation pattern to be set next time. A plurality of timings is set in the middle of the present pattern over one electrical angle period as candidates of switching from the present pattern to the next pattern, and the control device selects a command switching timing from among the plurality of timings. The control device switches the operation pattern from the present pattern to the next pattern at the selected command switching timing.

Abstract: A magnetic field sensor for sensing an absolute position of a target object can include one or more magnetic field sensing elements disposed proximate to a mechanical intersection of first and second portions of a target object, wherein the one or more magnetic field sensing elements are operable to generate a first magnetic field signal responsive to the movement of both the first and second portions. The magnetic field sensor can also include a position detection module operable to use the first magnetic field signal to generate a position value indicative of the absolute position. The magnetic field sensor can also include an output format module coupled to receive the position value and to generate an output signal from the magnetic field sensor indicative of the absolute position.

Abstract: A motor drive control device includes: a control circuit unit for outputting a drive control signal for performing advance-angle control of a motor to drive the motor; a motor driving unit for outputting a drive signal to the motor with a phase based on the drive control signal output from the control circuit unit to drive the motor; and a current detecting circuit for detecting a voltage value corresponding to a drive current of the motor, wherein the control circuit unit detects a cross-timing between the voltage value detected by the current detecting circuit and each of two or more reference voltage values, and performs the advance-angle control based on a detection result of the cross-timing to adjust a phase of the drive current.

Abstract: Various examples related to sinusoidal pulse width modulation (SPWM) techniques for harmonic and electromagnetic interference (EMI) noise suppression are provided. In one example, a method includes applying a DC offset to a sinusoidal modulation waveform to change an average duty cycle of a switching circuit; and controlling switching of an array of switches of the switching circuit based at least in part upon the offset sinusoidal modulation waveform and a carrier waveform, thereby reducing total energy. In another example, a system includes a switching circuit with an array of semiconductor switches that control application of a voltage source to a load; and controller circuitry that can control switching of the array of semiconductor switches by applying a DC offset to a sinusoidal modulation waveform to change an average duty cycle of the switching circuit.

Abstract: Insulation systems that present an electrical stress grading through the disposition of resistively graded networks between insulating layers is described. The resistively graded networks may be implemented by coating insulating material with resistive material, and wrapping the insulation material around a conductor. The resistive material may be linear or non-linear material. Fabrication of the insulating material, the resistive material, and the coating process are also discussed, as well as the application of the insulation to the conductor are also discussed.

Abstract: A power converter receives a DC supply voltage across a phase leg. The phase leg comprises an upper switching device and a lower switching device coupled across the DC link, wherein a junction between the upper and lower switching devices is configured to be coupled to a load. A gate driver is coupled to the phase leg activating the respective upper switching device according to an upper gate signal and activating the respective lower switching device according to a lower gate signal in response to a pulse-width modulation (PWM) control signal at a PWM frequency. The gate driver shuffles among a plurality of alternate paired sets of dead-time inserted signals. Each paired set of dead-time inserted signals corresponds to a different distortion of a current flowing in the load, so that overall distortion is dispersed.

Abstract: A motor control system is provided for compensating disturbance. The system includes a controller that supplies an input voltage to a motor based on the difference between a current command value to a motor and an actual current of the motor. A motor modeling part outputs a motor output current based on an input voltage from the controller and a disturbance observation part is formed as a reverse model of the motor modeling part to remove current noise using a current differentiation filtering method. Additionally, a disturbance compensation amount determination part determines a disturbance compensation amount based on the disturbance estimated by the disturbance observation part.

Abstract: Digital controller architecture for three-phase AC sources includes a phase accumulator, a command control, and a synchronization generator that are utilized to synchronize three controllers. Each controller provides the input to a separate power stage.

Abstract: A detecting apparatus for AC motor malfunction by using a current delay property of an AC motor and outputting a malfunction signal to an alarming device is presented. The detecting apparatus for AC motor malfunction includes a voltage phase delay setting unit, a voltage phase conversion unit, a current phase detecting unit, a current phase conversion unit, a phase comparator, a sawtooth wave generating unit, a phase difference detecting unit, a phase shift bandwidth setting unit, a noise filtering unit, and a malfunction signal output unit.

Abstract: A method is provided for operating a power tool having a motor powered by a battery. The method includes: delivering power from the battery to the motor in accordance with an operator input; detecting a condition of the power tool indicating a shutdown of the power is imminent; and fading the power delivered from the battery to the motor, in response to the detected condition, through the use of a controller residing in the power tool.

Abstract: A system and method for controlling an adjustable speed drive (ASD) to decelerate an AC load during a generating mode of operation is disclosed. The ASD includes a capacitor and an inverter coupled to a DC link. A current sensor system is coupled to an output of the inverter. The ASD further includes a control system programmed to calculate an energy of the capacitor, generate a reference power using the calculated capacitor energy, and calculate a feedback power from realtime current signals received from the current sensor system. The control system compares the feedback power to the reference power, defines a frequency offset based on the comparison, generates a speed command using the frequency offset, and outputs the speed command to the inverter to maintain a smooth DC link voltage during deceleration.

Abstract: According to an exemplary implementation, a power quad flat no-lead (PQFN) package includes a multi-phase inverter situated on a leadframe. The PQFN package further includes drivers situated on the leadframe and configured to drive the multi-phase inverter. The PQFN package also includes bootstrap diodes respectively coupled to the drivers. The bootstrap diodes are in a common integrated circuit (IC) that is situated on the leadframe. The common IC can include the drivers. The drivers can be high side drivers that are coupled to high side power switches of the multi-phase inverter. Also, the bootstrap diodes can be coupled to a supply voltage terminal of the PQFN package. Furthermore, the PQFN package can include wirebonds coupling the common IC to bootstrap supply voltage terminals of the PQFN package.

Abstract: A bridge output circuit includes an output terminal, a high side transistor, a low side transistor, a high side driver for controlling a gate voltage of the high side transistor, a low side driver for controlling a gate voltage of the low side transistor, and a controller for controlling the high side and low side drivers. The low side driver includes a first current source, a second current source, and a first assist circuit. The controller is configured to control the turning-on and turning-off states of the first current source, the second current source and the first assist circuit.

Abstract: A packaged device includes a first die, a second die, and specially spaced and positioned sets of package terminals. The first die includes a pulse-width modulator (PWM), a processor, a timer, high-side drivers, low-side drivers, and a fault protection circuit. The second die includes ultra-high voltage high-side drivers. In an ultra-high voltage application, the PWM and external circuitry together form a switching power supply that generates a high voltage. The high voltage powers external high-side transistors. The processor and timer control the ultra-high voltage high-side drivers, that in turn supply drive signals to the external high-side transistors through the package terminals. External low-side transistors are driven directly by low-side drivers of the first die. If the fault protection circuit detects an excessive current, then the fault protection circuit supplies a disable signal to high-side and low-side drivers of both dice.

Abstract: A control system (128) for controlling a switched reluctance (SR) machine (110) having a rotor (116) and a stator (118) is provided. The control system (128) may include a converter circuit (122) operatively coupled to the stator (118) and including a plurality of switches (132) in selective communication with each phase of the stator (118) and a controller (130) in communication with each of the stator (118) and the converter circuit (122). The controller (130) may be configured to determine a position of the rotor (116) relative to the stator (118), and generate a modulated switching frequency (152) based on the rotor position.

Abstract: In a control apparatus for a rotary electric machine receiving power from a DC power supply, a DC-AC converting circuit is provided with serially connected circuits each having high-potential-side and low-potential-side switching elements. When a short-circuit occurs at the switching elements, all the switching elements are turned OFF for failsafe and a path connecting the machine and the battery is opened. In such a case, a switching element belonging to part of the switching elements is turned ON, with potential at all the terminals of the rotary electric machine being the same. A location of the short-circuit occurs is identified, based on changes in current passing through the machine and being detected in response to turning ON the switching element. The changes are at least one of a reduction change in deviation of the current from a zero point and a reduction change in an absolute value of the current.

Abstract: The present invention relates to a motor controller employing bootstrap-capacitor supplies and in particular to the situation where the bootstrap supplies have to be charged, while the motor controller is connected to a spinning and energized motor. The present invention introduces a method of recharging based on choosing a recharging sequence from a set of recharging sequences, where the choice depends on the state of the connected motor and in particular on the back-EMF voltages of the motor.

Abstract: A combined battery charger and motor driver circuit assembly includes a rechargeable battery, a traction motor configured to accept a pulse-width-modulated (PWM) drive, a PNP transistor array, a charging source of chopped and rectified DC, and a control circuit configured to apply a discrete PWM drive signal to the gate of each transistor in the PNP transistor array.

Abstract: An switch array for use in a motor control circuit with a power source, controller and a motor includes a plurality of bidirectional switches positioned between the power source and the motor, wherein the bidirectional switches are PWM controlled by high speed control signals from the controller to provide power from the power source to the motor as desired, wherein the switch array is positioned substantially adjacent to the motor. The power source may be a three phase AC power source. The switches are preferably bidirectional gallium nitride (GaN) switches.

Abstract: A method serves for starting a polyphase electric motor which is operated in a star connection. The method conductively bridges at least one winding part of a phase of the motor and electrically disconnects the bridged winding part, in order in this manner, to supply a higher voltage to the remaining, electrically effective windings, and thus to increase the flow of current and thus the torque.

Abstract: An AC electric motor includes an annular A-phase winding WA wound in the circumferential direction of a stator, a stator pole group SPGA configured to generate magnetic flux ?A to interlink with the A-phase winding WA, an annular B-phase winding WB wound in the circumferential direction, and a stator pole group SPGB configured to generate magnetic flux ?B to interlink with the B-phase winding WB. The motor additionally includes a third stator pole group SPGC, N and S magnetic poles of the rotor, and X magnetic poles, which serve as third rotor poles, showing magnetic characteristics between the N and S magnetic poles of the rotor. DC currents are supplied to the A-phase and B-phase windings WA and WB to generate rotational torque.

Abstract: An electronic circuit for a power tool includes a plurality of high-side and low-side switches connected in series between terminals of a power source and coupled to a load, a bootstrap circuit comprising a plurality of bootstrap capacitors arranged to provide sufficient amount of drive voltage to turn ON and OFF the plurality of high-side switches, and a control unit configured to turn ON and OFF the plurality of low-side switches in succession to sequentially charge the bootstrap capacitors.

Abstract: A motor drive device includes an inverter circuit, a driver circuit for outputting a PWM signal to the inverter circuit, a booster circuit for boosting a power supply voltage supplied from a power supply circuit, a fail safe circuit arranged between the inverter circuit and the motor, and a fail safe drive unit for outputting a signal for turning ON/OFF a semiconductor switching element of the fail safe circuit. A boost voltage output from the booster circuit is supplied to the driver circuit and also supplied to the fail safe drive unit. The fail safe drive unit drives the semiconductor switching element of the fail safe circuit by such boost voltage.

Abstract: An inverter circuit for an electric motor includes a first terminal and a second terminal, via which the inverter circuit is connectable to an energy store. The inverter circuit also includes a parallel circuit having three half-bridge circuits located between the first terminal and the second terminal. Each of the half-bridge circuits includes in each case two switching devices, between which a half-bridge terminal, via which the respective half-bridge circuit is connectable to a respective input of an electric motor, is arranged in each case. The two switching devices of at least one of the half-bridge circuits are in each case configured to be driven linearly and to be operated as a current source, while the respective other switching device of the at least one half-bridge circuit is in the on state.

Abstract: A control unit for controlling commutation of a brushless direct current (BLDC) motor provided. The control unit controls high-side and low-side switches arranged between a power source and the motor and configured as a three-phase bridge to commutate the motor. The control unit is configured to provide drive signals to drive each of the high-side and low-side switches to control, for each phase of the bridge, a pulse-width modulation (PWM) of one of the high-side or low-side switches. For each phase of the bridge, immediately following a first cycle ending with a falling edge of the drive signal for one of the high-side or low-side switches, the control unit introduces a special commutation edge pulse in the drive signal of the other of the high-side or low-side switches to shunt the current from the motor before turning both the high-side and the low-side switches off during a second cycle.

Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.

Abstract: To make it possible to avoid an unstable state with a simple configuration even one of the phases of the motor fails. A motor drive system in accordance with the present invention includes a motor to which a plurality of phase coils of five phases or more are connected in a star connection, an inverter connected to one end of each of the phase coils, the inverter being configured to convert a DC power into an AC power and supply the AC power to each phase of the motor, a power relay disposed at another end of each of the phase coils, the power relay being configured so as to be able to cut off a supply power to at least one phase coil among the plurality of phase coils of the motor by using a plurality of contact points interposed between the star-connected coils, and a control unit that generates a control signal for the inverter and thereby controls driving of the motor.

Abstract: The present invention provides an electronic commutator circuit for use with a stator winding of an electrical machine. The stator winding of the electrical machine includes a number of coils linked by the same number of points of common coupling. The electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals. Each switching stage further includes a first reverse blocking semiconductor power device (such as a Reverse Blocking Gate Turn Off Thyristor (RB-GTO 1) capable of being turned on and off by gate control having its anode connected to the first dc terminal, and a second reverse blocking semiconductor power device (RB-GTO 2) capable of being turned on and off by gate control having its cathode connected to the second dc terminal.

Abstract: A control circuit includes a current sensing circuit, an analog digital converter (ADC), an amplifying circuit, a processor, and a switching circuit. The current sensing circuit senses current supplied to an electronic device by a power supply and outputs a first voltage signal. The amplifying circuit amplifies the first voltage signal output from the current sensing circuit to a second voltage signal. The ADC converts the second voltage signal to a digital signal. The processor outputs pulse width modulation (PWM) signals according to the digital signal. The switching circuit receives the PWM signals to control a fan of the electronic device according to the PWM signals.

Abstract: The present disclosure provides a brushless motor driving circuit capable of clamping an output voltage at a proper voltage, even when a power source voltage changes. Namely, a pre-driver circuit generates a voltage for driving a brushless motor from a source voltage by turning on/off first and second PMOS transistors and first and second NMOS transistors in an H bridge circuit of a drive voltage generating circuit, and applies the voltage to a coil of the brushless motor. A first clamp circuit turns on/off the first NMOS transistor on the ground side so that the output voltage at a first output terminal becomes equal to or lower than the source voltage. A second clamp circuit turns on/off the second NMOS transistor on the ground side so that output voltage at a second output terminal becomes equal to or lower than the source voltage.

Abstract: A method of braking a washing machine from an operational speed to a reduced non-zero speed is provided (as well as a washing machine incorporating the method) for a washing machine driven by one of a synchronous or asynchronous motor. Upon receipt of a speed reduction signal, the motor rotating magnetic fields are collapsed for a defined time period. After the defined time period, DC braking voltage is applied to the motor stator windings at a controlled ramp-up rate to an amplitude to generate a controlled ramped braking torque on the motor until the motor has slowed to a defined reduced speed. Thereafter, the amplitude of the DC braking voltage is set to 0V and the motor is soft started to an amplitude and reduced frequency needed to maintain the defined reduced speed.

Abstract: A multiphase motor driving device has an inverter circuit. The inverter circuit includes a pair of upper and lower switching elements, a shunt resistor for phase current detection, and a voltage for driving a multiphase motor. The device includes a determination unit for shifting a detection timing of the current flowing to the shunt resistor from the OFF period to the ON period of the switching element on the upper side in the phase. The determination unit determines whether or not ON failure occurs based on the current flowing to the shunt resistor of the phase in the ON period. The device has a current value estimation unit for estimating a current value of the phase in a case where the detection timing is shifted based on currents flowing to the shunt resistors of other phases.

Abstract: The present invention relates to a motor controller employing bootstrap-capacitor supplies and in particular to the situation where the bootstrap supplies have to be charged, while the motor controller is connected to a spinning and energized motor. The present invention introduces a method of recharging based on choosing a recharging sequence from a set of recharging sequences, where the choice depends on the state of the connected motor and in particular on the back-EMF voltages of the motor.

Abstract: A driving control apparatus includes an inverter circuit, a motor driving circuit and a motor control unit. In performing overlap energization, at a start time of an overlap time period, a pulse width of a first PWM signal at an energization side is widened to increase a number of pulses of a second PWM signal accordingly, and a first PWM signal at an energization side corresponding to a constant voltage side is also widened.

Abstract: Power conversion systems and methods are provided for driving a plurality of motor loads, in which an autotransformer receives AC input currents and provides a plurality of multiphase outputs at a non-zero phase angle relative to one another, and the individual multiphase outputs are provided to corresponding motor drives with rectifiers to convert the multiphase outputs to DC electrical power, and inverters to convert the DC power to AC to drive corresponding motor loads.

Abstract: A motor control device is electrically connected with a motor. The motor control device includes a controller and a driving circuit. The controller has a default value of time and generates a first driving signal and a second driving signal. The driving circuit includes a first switching element and a second switching element, the first switching element and the second switching element receive the first driving signal and the second driving signal respectively, and the first switching element and the second switching element are switched on or switched off alternately according to the first driving signal and the second driving signal respectively, so as to drive the motor to operate.

Abstract: An AC electric motor includes an annular A-phase winding WA wound in the circumferential direction of a stator, a stator pole group SPGA configured to generate magnetic flux ?A to interlink with the A-phase winding WA, an annular B-phase winding WB wound in the circumferential direction, and a stator pole group SPGB configured to generate magnetic flux ?B to interlink with the B-phase winding WB. The motor additionally includes a third stator pole group SPGC, N and S magnetic poles of the rotor, and X magnetic poles, which serve as third rotor poles, showing magnetic characteristics between the N and S magnetic poles of the rotor. DC currents are supplied to the A-phase and B-phase windings WA and WB to generate rotational torque.

Abstract: An object of the invention is to provide a motor-driving apparatus for driving a variable-speed motor, which increases a motor torque and efficiency at a high rotation speed. The motor-driving apparatus has a three-phase inverter and a boost DC/DC converter, which are operated the single-phase-switching method. The three-phase inverter consists of a nine-switch inverter applying the three-phase voltage to two three-phase windings of the motor. The single-phase-switching method reduces a switching power loss of the nine switch inverter largely. The boost DC/DC converter boosting a battery voltage reduces a copper loss of the inverter and the motor, too.

Abstract: A motor driver circuit for driving the gate node of a high-side driver transistor to a boosted voltage from a charge pump draws little or no static current from the charge pump. The gate node is pulled to the boosted voltage by a p-channel pullup-control transistor that is driven by p-channel transistors that are pumped by capacitors that cut off current flow to ground from the charge pump. An n-channel output-shorting transistor shorts the gate node to the output when the high-side driver is turned off. A coupling capacitor initializes the shorting transistor for each output transition. A p-channel output-sensing transistor generates a feedback to a second stage that drives the coupling capacitor. P-channel diode transistors and an n-channel equalizing transistor control the voltage on the coupling capacitor.

Abstract: A switch section includes a common terminal connected to a terminal at one end of each of a pair of motors, a first terminal connected to a terminal at the other end of one of the motors and a second terminal connected to a terminal at the other end of the other of the motors, and three-contact switches each including one common contact and two switching contacts. In the switch section two switches corresponding to one direction selected from the up and down directions form a switch group, at least one switch corresponding to the other direction selected from the up and down directions is provided, two switches corresponding to one direction selected from the left and right directions form a switch group, and at least one switch corresponding to the other direction selected from the left and right directions is provided.

Abstract: The present invention relates to a motor controller, including a converter for converting commercial AC power into DC power, an inverter including a plurality of switching elements, the inverter receiving the DC power, converting the DC power into AC power of a specific frequency through switching operations, and supplying the AC power to a three-phase motor, and a noise filter unit connected between the commercial AC power and the converter in order to remove a high frequency current and including normal mode inductors and common mode inductor. Accordingly, the motor control can control the power factor, limit a high frequency current, and eliminate noise components, that is, ripple components of an input current.

Abstract: A circuit arrangement for controlling an electrical load is provided with a bridge circuit which comprises four electronic switches with the load arranged in a transverse leg of the bridge circuit. A control circuit has respective control terminals for the four electronic switches. The control terminal for the first electronic switch is connected to the control terminal for the fourth electronic switch by means of a series connection consisting of a first capacitor and a first resistance, and the control terminal for the third electronic switch is connected to the control terminal for the second electronic switch by means of a series connection consisting of a second capacitor and a second resistance.

Abstract: The servo motor is controlled by a control signal from a control circuit. A common branch line is separated from a positive common line in accordance with information that a safety door is opened. Thus, a first gate drive circuit group is made inoperative. Then, a second gate drive circuit group is operated to thereby short-circuit the U?, V? and W?phases of the motor to place in a regenerative braking state.

Abstract: A radiation hardened motor drive stage utilizes a non-radiation hardened P-channel FET switch. The radiation hardened motor drive stage includes a non-radiation hardened P-channel FET switch that is connected three (3) pairs of upper and lower switch blocks or legs wherein the output of each pair is connected to a motor winding switch terminal. The upper switch blocks or legs are connected the P-channel switch a. The lower switch block or legs are connected to a negative power bus. The negative power bus permits the N-channel FETS or IGTS within the switch blocks or legs exposed to ionized radiation to be controlled, even when their gate threshold voltage has dropped below zero volts.

Abstract: A controller is capable of executing direct couple control that directly couples a first power device and a second power device without causing a DC/DC converter to convert voltage. During the direct couple control, a drive signal that causes no voltage conversion is intermittently output to at least one of a plurality of switching devices.