Abstract: A method for controlling a pulse-modulated DC-to-DC converter includes: applying a control signal to a driver of an LC filter, the driver coupling power to inputs of the LC filter when the control signal is asserted and decoupling power when the control signal is de-asserted; monitoring an inductor current and an output voltage of the LC filter; calculating a goal current based at least in part on inductor energy needed to recharge an output capacitor in the LC filter; asserting the control signal when the goal current exceeds a threshold; and de-asserting the control signal when the inductor current reaches the goal current. An illustrative controller embodiment produces a trigger signal that sets a flip flop when the goal current exceeds the inductor current by more than a threshold amount; and resets the flip flop when the inductor current exceeds the goal current.

Abstract: An electric power conversion device of an embodiment includes the electric power conversion device expressed as an equivalent circuit including, a power supply, a first parasitic inductance, a first diode; a second parasitic inductance connected to the first diode in series, a second diode connected to the first diode in parallel, a third parasitic inductance connected to the second diode in series, a switching element, a gate circuit, and a load. The equivalent circuit includes a first circuit loop and a second circuit loop. The first circuit loop includes the power supply, the first parasitic inductance, the first diode, the second parasitic inductance, the switching element, and the gate circuit. The second circuit loop includes the power supply, the first parasitic inductance, the second diode, the third parasitic inductance, the switching element, and the gate circuit.

Abstract: A control circuit controls a switching element in a switching power supply unit. The control circuit includes: a controller connected to the switching element; a signal generating circuit connected to the input part of the controller; a reference voltage source connected to the signal generating circuit; and a comparator having a first input terminal to which an output voltage is input from the switching power supply unit, a second input terminal to which a comparison signal is input from the signal generating circuit, and an output terminal connected to the signal generating circuit and to the input part of the controller.

Abstract: An electronic device may include a plurality of voltage rails to provide voltages to components of a load, a plurality of voltage regulators, and a buck converter apparatus to separately couple to more than one of the plurality of voltage rails and to provide a voltage to at least a specific one of the voltage rails.

Abstract: A voltage generating circuit, in which the influence of offset of an amplifier on an output voltage is reduced, has first and second bipolar transistors (Q1, Q2) having emitter terminals at the same electric potential. A base terminal of Q1 is disposed on a collector side of Q2. A first resistance element connects the collector side of Q2 with the base side of Q2; and a second resistance element (R1) connects a collector side of Q1 to R2. A third resistance element (R3) connects a base terminal of Q2 with the electric potential of the emitter terminals. An amplifier (A1) outputs a voltage based on a voltage difference between the collector sides of Q1 and Q2; and a voltage-current converting section (MP1, MP2) converts amplifier output into a current supplied to the connection node of R1 and R2. A voltage is then output on the basis of the generated current.

Abstract: An apparatus, e.g., a boost converter, includes a first switch configured to be coupled to an inductor and to support a charging current in the inductor from a power source and at least two serially-coupled second switches coupled in parallel with the first switch and configured to selectively route current from the inductor to at least two serially-connected capacitors. The apparatus may further include a control circuit configured to operate the first switch and the plurality of second switches.

Abstract: An apparatus (200) for tuning a feedback loop that is arranged to regulate an output voltage (Vout) of a switched mode power supply, SMPS (100), in accordance with a control law defined by control law parameters. The apparatus includes a natural frequency estimator (210) arranged to determine a respective estimate of a natural frequency of each of two zeros in a transfer function that corresponds to a model of the feedback loop.

Abstract: An electric power conversion device includes a plurality of cell converters connected in cascade and including main circuits, drive circuits, and self-feeding devices for supplying power to the drive circuits by being supplied with power from the main circuits. The drive circuit is supplied with power via a first feed line from the self-feeding device in the corresponding cell converter, and supplied with power from the self-feeding device in another cell converter via a second feed line on which an insulation input/output circuit is provided. When the self-feeding device is abnormal, the drive circuit is supplied with power from the self-feeding device in the other cell converter, whereby the electric power conversion device continuously provides a desired output.

Abstract: A zero current detecting circuit is disclosed. The zero current detecting circuit includes a first zero current comparator for determining current variation on an inductor of a synchronous switching power converter so as to output a zero current signal to turn off a down-bridge transistor of the synchronous power converter; a second zero current comparator for determining whether the first zero current comparator turns off the down-bridge transistor too early or too late and outputting a comparison result; a counter coupled to the second zero current comparator for ascending or descending a control bit according to the comparison result, and an adjustable delay unit coupled to the first zero current comparator and the counter for adjusting a delay time according to the control bit, and delaying and outputting the zero current signal according to the delay time, to compensate a negative offset voltage by delay.

Abstract: A switching power converter includes an inductor coupled to a terminal operably supplied with an input voltage. A semiconductor switch is coupled to the inductor and configured to enable and disable an input current passing through the inductor in accordance with a drive signal. A current sense circuit is coupled to the inductor or the semiconductor switch and is configured to generate a current sense signal representing the input current passing through the inductor or the semiconductor switch. A control circuit receives the current sense signal and is configured to: close the semiconductor switch regularly in accordance with a clock frequency, to integrate the current sense signal thus providing an integrated current sense signal to compare the integrated current sense signal with a threshold that is a function of the input voltage.

Abstract: Systems and methods are provided for regulating a power conversion system. An example system controller includes a first controller terminal and a second controller terminal. The first controller terminal is configured to receive a first signal associated with an input signal for a primary winding of a power conversation system. The second controller terminal is configured to output a drive signal to a switch to affect a first current flowing through the primary winding of the power conversion system, the drive signal being associated with an on-time period, the switch being closed during the on-time period. The system controller is configured to adjust a duration of the on-time period based on at least information associated with the first signal.

Abstract: An apparatus and method for supplying power to an electronic device are provided. The apparatus includes a power converter, a main converter, and a sub converter. The power converts includes a rectifier configured to convert alternating current (AC) power into direct current (DC) power, and a smoothing condenser connected to an output terminal of the rectifier. The main converter is connected with an output terminal of the power converter and configured to supply power to a first component of the electronic device. The sub converter is connected with the output terminal of the power converter, and configured to supply power to components other than the first component, and to stop supplying the power in response to a momentary power interruption or a voltage dip occurring in the AC power.

Abstract: Disclosed is a switching power-supply device that induces a pulse voltage in a secondary winding of the transformer, and outputs, to a load, an output voltage rectified and smoothened by a secondary-side rectification smoothing circuit including a rectifier diode and a smoothing capacitor. An input-voltage detection circuit detects the input voltage of the alternating-current power supply. An error amplifier compares the output voltage with a reference voltage, and transmits a resultant error voltage to a primary side as a feedback signal. An internal oscillation circuit selects any of frequency decrease settings according to the input voltage detected by the input-voltage detection circuit, and performs, by using the selected frequency decrease setting, a frequency decreasing function of decreasing a switching frequency of the switching element at a light load, in response to the feedback signal transmitted from a secondary side to inform a state of the load.

Abstract: A controller for adjusting an output voltage of a power converter includes a gate control signal generation circuit, a feedback signal detection module, and a reference voltage generation module. The gate control signal generation circuit generates a gate control signal to a power switch of a primary side of the power converter according to a reference voltage and a plurality of signals corresponding to the primary side and a secondary side of the power converter. The feedback signal detection module generates a logic signal according to a combination corresponding to the plurality of signals. The reference voltage generation module generates the reference voltage to the gate control signal generation circuit according to the logic signal. The power switch adjusts the output voltage of the secondary side of the power converter according to the gate control signal.

Abstract: The present invention provides a flyback power converter, a secondary side control circuit, and a control method thereof. The flyback power converter converts an input voltage to an output voltage, and provides a load current to a load circuit. The flyback power converter includes: a transformer circuit, a power switch circuit, a switch current sense circuit, a primary side control circuit, and a secondary side control circuit. The secondary side control circuit adaptively adjusts a frequency of a zero of a compensator gain function and/or a mid-frequency gain of the compensator gain function according to the load current, such that a number of poles of a system open loop gain function of the flyback power converter is at most more than a number of zeroes of the system open loop gain function by one under a crossover frequency.

Abstract: A power source capable of supplying power to operate electronics of a system is disclosed. In one example, the power source takes advantage of an electrical potential difference between primary and secondary grounds. The power source can reduce system cost and power consumption.

Abstract: A method and semiconductor device for controlling skip mode operation during light load conditions in a resonant power converter includes a skip mode controller circuit that compares a feedback signal corresponding to the secondary output level with a reference voltage to determine when to invoke skip mode. When entering skip mode the skip mode controller ceases switching by turning on the lower switch for a prolonged time to leave the resonant capacitor partially charged. Upon resuming switching, the lower switch is turned on first to drive current through the inductances, and asymmetric switching is used where the upper switch is on, initially for shorter periods to allow zero voltage switching. If the load increases, the on-time of upper and lower switches converge and conventional symmetric switching resumes.

Abstract: A DC/DC converter includes: a transformer; a main MOS transistor connected in series between a primary side inductance of the transformer and a ground potential; a synchronous rectification MOS transistor connected in series between a secondary side inductance of the transformer and the ground potential; a refluxing MOS transistor connected between a secondary side output of the transformer and the ground potential; and a controller. If an operation is stopped, the controller stops the main MOS transistor and stops the synchronous rectification MOS transistor and the refluxing MOS transistor after a lapse of a predetermined period of time.

Abstract: A switching power supply device includes: a transformer; a first switch connected between a high potential terminal of an input DC voltage source and a primary winding; a second switch connected between a low potential terminal of the input DC voltage source and a primary winding; a control circuit outputting a driving pulse signal for synchronizing the first and second switches; first and second rectifying devices; a synchronous rectifier circuit; and a positive bias circuit that applies a positive bias to a control terminal of one of the first and second switches so as to constantly turn the one of the first and second switches ON. When the first and second switches stop a switching operation while an output voltage exists between the output terminals, the positive bias circuit applies the positive bias to the one of the first and second switches.

Abstract: Switching regulator methods and systems for supplying output current at a regulated voltage level to a load. The regulator has a primary side that is galvanically isolated from a secondary side. The regulator includes a transformer having a primary winding on the primary side and a secondary winding on the secondary side, coupled to a load. A switch, coupled to the primary winding, controls current flow through the primary winding. A first feedback control loop, responsive only to primary side signal values, regulates a constant average voltage at the output node. An optional second feedback control loop, responsive only to primary side signal values, reduces voltage ringing at the output node.

Abstract: Included are a switching power supply device main body, and a frequency control circuit that controls the switching frequency of a switching element in accordance with a feedback signal in accordance with the output voltage of the switching power supply device main body. The frequency control circuit is divided into a frequency control region wherein the amount of the feedback signal is greater than a predetermined boundary value and a frequency control region wherein the amount is less, linear frequency control whereby the switching frequency of the switching element is caused to change linearly in accordance with the feedback signal is executed in the frequency control region wherein the feedback amount is less, and linear cycle control whereby the switching cycle of the switching element is caused to change linearly in accordance with the feedback signal is executed in the frequency control region wherein the feedback amount is greater.

Abstract: A DC power supply device including a DC/DC converter having FETs each driven by a drive transformer. A voltage from a single drive power supply disposed in common for the FETs is divided into positive and negative biases to be applied to the FETs, and an operational state of the FETs is detected based on voltage signals. A sequence circuit turns on an input from a three-phase AC power supply by driving a relay circuit at a time point when it is confirmed that the FETs have normally started stable ON/OFF operation, and drives a power factor improvement circuit, which converts AC voltage from the three-phase AC power supply into a DC voltage by simultaneously performing full-wave rectification and power factor improvement.

Abstract: A power transfer system includes DC-DC power conversion circuitry that has a first switch and a second switch on either side of a transformer with a first capacitor and a second capacitor cross-connected across the transformer. A direction of power transfer is determined, and primary and secondary sides of the DC-DC power conversion circuitry are aligned based on the direction of power transfer. A quantity of power transfer through the DC-DC power conversion circuitry is determined based on power and voltage characteristics of electrical components. A duty cycle and a switching frequency for the first switch or second switch is determined based on the quantity of power to be transferred. The primary and secondary switches are controlled using switching.

Abstract: Converters (1) for supplying pulsed power to light sources (8) comprise switching parts (2) and controlling parts (3) for adapting switching parameters of the switching parts (2) for improving a performance. The switching part (2) may comprise first/second switches (41, 42) that are in first/second modes during a first time interval of a cycle and vice versa during a second time intervals of a cycle. A group of cycles results in a pulse of the pulsed power. A switching parameter such as the first time interval of a first cycle may be shortened to reduce overshoot. A switching parameter such as the second time interval of the first cycle may be shortened or lengthened. A switching parameter such as the second time interval of a last cycle may be lengthened or shortened to reduce overshoot. A third switch (93) for switching the light source (8) is activated and de-activated delayedly to improve transient behavior.

Abstract: A parallel resonant converter including a control circuit and at least two resonant conversion circuits connected in parallel between an input bus and an output bus is provided by the invention. The control circuit is configured to provide a switching frequency signal to the at least two resonant conversion circuits. Moreover, the control circuit is further configured to control the voltage of the output bus to linearly vary along with the switching frequency signal in a rated range by using a linear current-balancing curve (gain-frequency), and thus achieving the purpose of current-balancing for the at least two resonant conversion circuits. The invention is capable of controlling the output voltage of the parallel resonant converter, so as to reduce the ripple on the output voltage of the power supply system.

Abstract: First and second switch are connected in series to both terminals of a DC power source. A series circuit comprising a reactor, a primary winding of a transformer, and a capacitor connected in series, and is connected to a node between the first and second switches and one terminal of the DC power source. A rectifier smoothing circuit rectifies and smoothens a voltage generated across a secondary winding of the transformer and outputs a DC voltage. A control circuit alternately turns the first and second switches on and off. A voltage detection circuit detects the DC voltage from the rectifier smoothing circuit. A signal generation circuit generates a feedback signal from the DC voltage detected by the voltage detection circuit, and outputs the signal for turning the first and second switches on and off. A load current detection circuit detects load current contained in resonance current flowing through the capacitor.

Abstract: A power conversion device includes: a DC current calculation unit for calculating a circulating current component for each phase which circulates between the phases through first arms and/or second arms not via an AC power supply and a DC power supply; and a circulating current control unit for controlling the circulating current component for each phase so as to follow a predetermined circulating current command value, thereby reliably suppressing variation in voltages of DC capacitors of unit cells among the phases even in such a case where an impedance is additionally inserted in a DC circuit.

Abstract: Techniques for supplying auxiliary power to AC powered lighting devices are disclosed. An auxiliary power supply can be used, for example, to provide auxiliary power to lighting control circuitry, an LED driver, or any other electronic lighting device. In some example embodiments, the linear regulator is connected to a switch that is controlled by a control circuit such that the linear regulator operates only when the instantaneous line input voltage is in a certain range where the linear regulator has a somewhat good efficiency. In such cases, when the linear regulator is operating, energy is stored with an auxiliary capacitor connected to the output of the linear regulator. In some embodiments, the linear regulator is configured to operate only when the line voltage is between a determined upper and lower voltage threshold; while in other cases the linear regulator is configured to operate only when the line voltage is increasing through the predetermined voltage threshold values.

Abstract: It is presented a converter arm for power conversion. The converter arm comprises: a plurality of converter cells, wherein each converter cell comprises a plurality of semiconductor switches, an energy storage element and at least three control signal connections arranged to control the conducting state of the plurality of semiconductor switches. Each converter cell is connected to receive a control signal from at least three entities via said control signal connections, wherein at least two of the three entities are neighboring converter cells, and each converter cell is arranged to forward a control signal to all connected neighboring converter cells via said control signal connections. A corresponding converter device is also presented.

Abstract: An inverting apparatus and a control method thereof are provided. The inverting apparatus includes an inverting circuit, a detection circuit, and a control circuit. The control circuit is coupled to the inverting circuit and the detection circuit and configured to provide a control signal to control the inverting circuit so as to adjust a voltage value of an input voltage into a command voltage represented by the control signal. The control circuit calculates a voltage difference between the detected input voltage and the command voltage so as to determine whether the voltage difference is greater than a preset value. When determining that the voltage difference is greater than the preset value, the control circuit sets the voltage value of the command voltage as the voltage value of the current input voltage.

Abstract: A method is described for the pulse-width-modulated control of switching elements of a pulse-controlled inverter, the impulses of successive signal periods of the control signal, in a first control mode, respectively having a uniform start or end time within the signal period, or being situated uniformly centered in the middle of the signal period, and the impulses of successive signal periods of the control signal, in a second control mode, being situated alternately at the beginning of the signal period and at the end of the signal period.

Abstract: A circuit includes first and second electronic switches, first and second excitation circuits, and first and second inductors. The first and second electronic switches are electrically coupled in series. The first and second excitation circuits are used for respectively controlling the first and second electronic switches to be turned on and turned off and are configured to synchronously switch the first and second electronic switches. The first inductor is electrically coupled between the first excitation circuit and the first electronic switch, for transmitting the switch control signal of the first excitation circuit to the first electronic switch. The second inductor is electrically coupled between the second excitation circuit and the second electronic switch, for transmitting the switch control signal of the second excitation circuit to the second electronic switch.

Abstract: A phase leg for a multilevel inverter includes a positive DC lead, a first outer MOSFET connected to the positive DC lead, a first inner IGBT connected to the first outer MOSFET, a second inner IGBT connected to the first inner IGBT, and a second outer IGBT connected to the second inner IGBT. The first and second outer MOSFETs are superjunction MOSFETs voltage balanced by the first and second IGBTs for reducing voltage stress in the solid-state switch phase leg when the superjunction MOSFET and the IGBT are conducting current from the DC lead to the AC lead.

Abstract: An alternating current to direct current converter system includes an alternating current power supply, an external electronic load, a first MOS transistor, a first control module, a first switch and a second control module. The alternating current power supply includes a first output end and a second output end. The first control module controls the first MOS transistor to active when the first output end has a positive voltage and control the first MOS transistor to turn off when the second output end has a positive voltage. The first switch connects to a first end of the external electronic load and the second output end. The second control module connects to the first switch. The second control module controls the first switch to active when the second output end has a positive voltage and controls the switch to turn off when the first output end has a positive voltage.

Abstract: Technologies for communicating information from an inverter configured for the conversion of direct current (DC) power generated from an alternative source to alternating current (AC) power are disclosed. The technologies include determining information to be transmitted from the inverter over a power line cable connected to the inverter and controlling the operation of an output converter of the inverter as a function of the information to be transmitted to cause the output converter to generate an output waveform having the information modulated thereon.

Abstract: A transducer, and a method for manufacturing the transducer are provided. The transducer includes a substrate-side electrode provided in one side of an insulative substrate and an opposite plate including an opposite electrode disposed opposite to the substrate-side electrode, and which performs a function such as a reduction in impedance, conversion of capacitance, signal amplification, thereby achieving size reduction of the transducer itself. An upper plate is made of a silicon monocrystal and is arranged so as to face a substrate-side electrode. In the upper plate, an integrated circuit section which is an impurity region of an IC circuit is formed by a thermal diffusion method or an ion implantation method. By this transducer, an improvement in conversion efficiency, an improvement in productivity, and a size reduction of a mount system are achieved.

Abstract: A vibration wave actuator includes a vibrator, a driven element, and a magnet. The vibrator has at least an electro-mechanical energy conversion element and an elastic body to which the electro-mechanical energy conversion element is joined, the elastic body including a contact portion. The driven element is in pressure contact with the contact portion of the vibrator, and includes a magnetic substance. The magnet is arranged such that the vibrator is placed between the driven element and the magnet.

Abstract: Disclosed is a magnet in a high vacuum tube levitated by at least one magnet outside the tube and stabilized by at least one diamagnet inside or outside the tube. The magnet may have a rotational symmetry axis aligned with the magnetization axis and the diamagnet may be laminated to minimize eddy-current damping. The magnet or magnets outside the tube are used to control the levitation position and to temporarily bring the magnet into contact with a part of the tube structure. Contact is used in combination with a rotor to initiate the spinning motion of the magnet. The passively spinning and levitating magnet will continue to spin for an unusually long period of time due to the lack of contact and extremely low air drag and eddy-current friction.

Abstract: A drive device for a vehicle, in particular a rail vehicle, includes a set of drive units each having at least one electric traction motor and a power generation unit which is provided for generating power for the traction motor, and a set of motor contactor units each being assigned to a traction motor. In order to provide a type of drive device which has a high availability in the event of a failure, has few structural elements and can be produced economically, at least one motor contactor unit includes at least one switching device which is connected between the power generation unit for the associated traction motor and a feed point.

Abstract: A power source device includes a power source body including first and second secondary batteries and an inverter. When the power source connection status is switched from parallel to serial statuses, the motor generator is operated as a motor and the power source connection status is switched to a single second power source status, after switching to the first connection status in which the power source body and the first inverter are connected, the first motor generator operates as a motor, and power source connection status is switched to a single second power source status, and the inverter connection status is switched to a second connection status in which the power source body in the single second power source status and the inverter are connected.

Abstract: Provided is a power conversion device, including a fault determination unit (11) for determining, based on phase voltages of a polyphase dynamo-electric machine (4) detected by phase voltage detection units (10), a power, earth, or open fault of armature windings of the polyphase dynamo-electric machine (4). The fault determination unit (11) determines, in a state that all power semiconductor switching elements (2) are in an off state and no induction voltage is generated in the armature windings of the polyphase dynamo-electric machine (4), the power fault when all the phase voltages are substantially equal to an anode potential of a DC power supply (3), the earth fault when all the phase voltages are substantially equal to a cathode potential of the DC power supply (3), and the open fault when all the phase voltages are not substantially the same potential.

Abstract: In a thyristor control device which converts a first AC voltage to a DC voltage and converts the DC voltage to a second AC voltage to be supplied to a synchronous motor, a DC voltage detector is configured to detect the DC voltage, and is provided with an AC voltage detector configured to detect the second AC voltage and an arithmetic circuit configured to determine the DC voltage on the basis of the second AC voltage detected by the AC voltage detector. As a result, there is no need to separately provide a DV voltage detector, which makes it possible to make the device compact in size and cheap in price.

Abstract: There are disclosed herein various implementations of a method and a system enabling operation of a motor in reverse. Such a method includes applying a first drive signal to begin rotating the motor in a reverse direction, the first drive signal being applied for a predetermined period of time. The method also includes using a position sensor signal for the motor to control motor drive in the reverse direction when the motor reaches a predetermined reverse speed, and operating the motor in the reverse direction.

Abstract: An output MOS transistor has a drain connected with a power supply and a source connected with an output terminal. The short-circuit MOS transistor has a source connected with the output terminal. The short-circuit MOS transistor is formed in a semiconductor substrate connected with the power supply. A switching device is formed in a semiconductor region which is formed in the semiconductor substrate, and contains a first diffusion layer connected with the gate of the output MOS transistor and a second diffusion layer formed in the semiconductor region and connected with the drain of the short-circuit MOS transistor.

Abstract: A system and method for controlling the main field current in an electrical generator is disclosed. The system can include a controller to sense the voltages and currents in the system to identify load faults. The system can also comprise one or more switches and an energy dissipator to absorb, store, or dissipate the main field current in the event of a load fault, such as a short circuit. In the event of a load fault, the controller can change the position of the one or more switches to redirect the main field current from the main field windings of the rotor to the energy dissipator. The energy dissipator can absorb or store the main field current significantly reducing the time required to stop the output current of the generator.

Abstract: A controller includes a voltage determination module, a bus voltage command module, and a power factor correction (PFC) control module. The voltage determination module determines a desired direct current (DC) bus voltage for a DC bus electrically connected between a PFC module and an inverter power module that drives a motor. The voltage determination module determines the desired DC bus voltage based on at least one of torque of the motor and speed of the motor. The bus voltage command module determines a commanded bus voltage based on the desired DC bus voltage. The PFC control module controls the PFC module to create a voltage on the DC bus that is based on the commanded bus voltage.

Abstract: An ac synchronous electrical machine includes a stator and a multi-phase stator winding that defines a plurality of stator poles. The stator winding has two or more coil groups, each coil group including a plurality of coils for each phase that are received in winding slots in the stator. The stator winding is connected to a power source/sink. The coil groups are connected in series and each coil group is connected to a power source/sink by a respective switch (26a, 26b . . . ). This allows one or more of the coil groups to be selectively supplied with power from the associated power source/sink or selectively supply power to the associated power source/sink. The switches are operated by a controller. The coils in each coil group are arranged substantially symmetrically around the circumference of the stator to define selected poles of the electrical machine and to produce a constant and balanced rotating torque when any particular coil group or combination of coil groups is active.

Abstract: Reduced is occurrence of hunting in which a power factor corrector continuously turns on and off alternately for a short period of time. A power factor correction controller turns on a power factor corrector if a parameter value for an input current into the power factor corrector is greater than or equal to a first threshold, and turns off the power factor corrector if the parameter value is smaller than or equal to a second threshold below the first threshold. Through a predetermined time period from a moment when the power factor corrector is switched either from on to off or from off to on, the power factor correction controller maintains a state of the switched power factor corrector, regardless of the parameter value.

Abstract: Weighing system (FIG. 3, FIG. 6) to weigh items, parcels and the like while they are moving, for example, on a conveyor. A servo amplifier (14) and servo controller (20) are arranged to drive a servo motor in a feedback (15) configuration, and acquire torque sensing signals (17) responsive to commanded acceleration of the conveyor while the item(s) are on board. Preferably, constant acceleration of the item(s) is realized during one or more measurement intervals, and mass is derived by a processor (30) based on the measurement data (FIG. 5). Other embodiments are described for weighing granular and slurry materials (FIG. 7) and for weighing multiple, potentially overlapping, parcels in motion (FIG. 8).

Abstract: A door opening/closing control device includes: a controller controlling driving of an actuator opening or closing a door; a position detector detecting an opening/closing position of the door; a speed calculator calculating an opening/closing speed of the door based on a temporal change in the opening/closing position detected by the position detector; and a target assisting force calculator calculating target assisting force based on the opening/closing position and the opening/closing speed of the door. The controller controls the driving of the actuator to assist an operation of opening or closing the door based on the target assisting force calculated by the target assisting force calculator. Further, the controller controls the driving of the actuator such that the door is fully closed upon judgment that the opening/closing position of the door is in the vicinity of the fully closed position based on the opening/closing position detected by the position detector.