Abstract: A PFC circuit includes: a boost inductor, an auxiliary winding, an auxiliary switch tube, a main switch tube, a clamping capacitor, a series resistor and a control module; the boost inductor and the auxiliary winding have mutual inductance, a first terminal of the auxiliary winding is connected to a first terminal of the auxiliary switch tube, a second terminal of the auxiliary switch tube is connected to a first terminal of the clamping capacitor, a second terminal of the clamping capacitor is connected to a first terminal of the series resistor, and a second terminal of the series resistor is connected to a second terminal of the auxiliary winding; the main switch tube is connected between the boost inductor and the ground; and the control module is respectively connected to a control terminal of the main switch tube and a control terminal of the auxiliary switch tube.

Abstract: A voltage-controlled oscillator (VCO) generates a clock signal in response to an input feedback signal by applying tuning to a control loop error signal related to the input feedback signal and generating the clock signal using a voltage ramp signal that is ground referenced. The VCO includes an input tuning circuit applying tuning to a difference signal to generate a tuned voltage signal, a comparator to compare the tuned voltage signal to the ground-based ramp signal, an one-shot circuit to generate an one-shot signal pulse in response to the ramp signal increasing to the tuned voltage signal. The one-shot signal pulse is the clock signal and is also used to reset the ramp signal. In some embodiments, the voltage-controlled oscillator of the present disclosure is incorporated in a current mode hysteretic modulator.

Abstract: A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

Abstract: A phase-redundant voltage regulator apparatus includes groups of regulator phases, each having a multi-phase controller (MPC) connected to each regulator phase. The MPC transfers, to control logic, phase fault signals and a pulse-width modulation (PWM) phase control signal received from the regulator phases of a phase group. Spare regulator phases include output ORing devices to limit current flow into spare regulator phase outputs. Output switching devices are configured to electrically couple spare regulator phase outputs to a common regulator output. Control logic is connected to the phase groups MPC and asserts phase enable signals to, transfers PWM phase control signals to, and receives phase fault signals from the spare regulator phases. The control logic electrically interconnects a spare regulator phase to a phase group including a failed regulator phase in response to receiving a phase fault signal from an MPC.

Abstract: A solar module can have its output processed based on the frequency responses. The high and low frequency responses can be processed separately, thus allowing the solar module to respond optimally to the rapid fluctuation of power generation, such as due to changes in weather.

Abstract: An LED drive circuit with leakage protection and ballast includes a first filtering circuit, a rectifying circuit, a power module, a second filtering circuit, a compatibility and leakage protection circuit and a LED load, the input of the first filtering circuit is connected to a power input, the output of the first filtering circuit is connected to the input of the rectifying circuit, the output of the rectifying circuit is connected to the input of the second filtering circuit, the output of the second filtering circuit is connected to the input of the power module, the output of the power module is connected to the LED load, the input of the compatibility and leakage protection circuit is connected to the input of the rectifying circuit and the input of the second filtering circuit, and the output of the compatibility and leakage protection circuit is connected to the rectifying circuit output.

Abstract: An integrated circuit includes an output terminal a first input terminal is configured to receive a signal proportional to a voltage between first and second terminals of the primary winding, and a second input terminal is configured to receive a signal proportional to a current flowing through the primary winding. A quasi-resonant (QR) circuit has a first input coupled to the first terminal, and a second input coupled to an output of an oscillator circuit. A selector circuit has a first input coupled to the output of the oscillator circuit, a second input coupled to an output of the QR circuit, and a select input. An output control circuit includes a first input coupled to the second input terminal, a second input coupled to an output of the selector circuit, and an output coupled to a control terminal of the switching transistor.

Abstract: A boost PFC converter includes a rectifier, a converter and an output stage comprising an output capacitor where the DC output voltage is provided across the output capacitor. The rectifier includes four rectifying elements connected in a full bridge configuration where the upper two of these four rectifying elements are thyristors and where the lower two are diodes. In that the thyristors are controlled such as to be open for only a part of each half period of the input voltage, the amount of current per half period that is passed to the output capacitor is controllable and can be made very small. Accordingly, the charge current for precharging the output capacitor can be controllably limited such that a bulky precharge resistor is not required anymore to avoid high inrush currents.

Abstract: A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

Abstract: A phase control device includes: at least one switching element connected to an AC power source, the switching element being capable of: turning on and off at specified timings; delivering AC power to a load upon turn-on and cutting it off upon turn-off; and keeping an on-time from the start to the end of turn-on and an off-time from the start to the end of turn-off, the on-time and off-time being variable; a timing setting portion that sets a turn-on and turn-off timing for turning on and off the switching element; a judgment portion that judges whether or not the turn-on and turn-off timing are on at a phase within a first or second phase range; and a processor that starts turning on and off the switching element at the turn-on and turn-off timing, the processor being capable of adjusting the on-time and off-time depending on the judgment result.

Abstract: An AC/DC converter includes: a first terminal and a second terminal for receiving an AC voltage and a third terminal and a fourth terminal for supplying a DC voltage. A rectifying bridge includes input terminals respectively coupled to the first terminal and the second terminal, and output terminals respectively coupled to the third terminal and fourth terminal. A first branch of the rectifying bridge includes, connected between the output terminals, two series-connected thyristors with a junction point of the two thyristors being connected to a first one of the input terminals. A second branch of the rectifying bridge is formed by series connected diodes. A control circuit is configured to generate control signals for application to the control gates of the thyristors.

Abstract: Embodiments of a circuit for controlling DC offset error for an inductor current ripple based, constant-on time DC-DC converter are disclosed. The circuit includes a ripple generation circuit coupled to a reference voltage input and to a sense voltage input, and having a reference voltage output to form a main loop. The circuit also includes a DC error correction circuit connected between the reference voltage input and the sense voltage input, and the reference voltage output of the ripple generation circuit. The DC error correction circuit includes a coarse DC error correction loop coupled between the sense voltage input and the reference voltage output and a fine DC error correction loop coupled between the reference voltage input and the reference voltage output. A method for controlling DC offset error for an inductor current ripple based, constant-on time DC-DC converter, is also disclosed.

Abstract: An error amplifier amplifies a difference between a feedback signal VFB that corresponds to an output voltage VOUT of a DC/DC converter and its target value VREF, so as to generate an error signal VERR. A pulse width modulator for each channel is configured as a peak current mode modulator comprising a PWM comparator that compares a current detection signal VIS with the error signal VERR, and a logic circuit. When the number of enabled channels is switched, a soft shedding circuit selects at least one channel as a correction target channel. The soft shedding circuit generates a correction signal VCORR for each correction target channel, and superimposes each correction signal VCORR on at least one of two inputs of the corresponding PWM comparator.

Abstract: A power control system includes a multi-phase power source, an ungrounded multi-phase load, a plurality of power switching circuits and a plurality of zero-crossing circuits. The multi-phase power source includes a plurality of phase power outputs. The plurality of power switching circuits are each connected to provide power from one of the plurality of phase power outputs to the ungrounded multiphase load. The plurality of zero-crossing circuits are connected to provide control signals to the plurality of power switching circuits. Each of the plurality of zero-crossing circuits are connected between one of the plurality of power phase outputs and an ungrounded reference.

Abstract: Systems, methods, and devices are disclosed for implementing a bootstrapped power circuit. Devices may include a controller configured to generate an output signal. Devices may include a power converter configured to receive the output signal, configured to store an amount of energy in response to receiving the output signal, and further configured to release the amount of energy in response to detecting a change in the output signal. Devices may include a switch configured to be toggled between a first and second position. Devices may include a power source configured to store a second voltage having a second amplitude. Devices may include a bootstrap circuit configured to receive a third voltage from the power source when the switch is in the first position, and configured to receive at least some of the amount of energy from the power converter when the switch is in the second position.

Abstract: A boost chopper circuit is described that an alternating current (AC) power source; at least one inductor connected to said AC power source; a rectifier connected to said inductor and AC power source; at least one switch shorting our said rectifier; a series circuit connected in parallel with said switch of at least one diode and a capacitor; and a load connected in parallel with said capacitor. A control technique is employed that includes turning on and off the switch in order to keep the average current per pulse cycle proportional to the AC input voltage during the same pulse cycle.

Abstract: A multiphase regulator includes a plurality of output phases, each operable to deliver a phase current through a separate inductor to a load connected to the output phases via the inductors and an output capacitor. The multiphase regulator further includes a controller operable to regulate a voltage delivered to the load by adjusting the phase currents delivered to the load by the output phases, and monitor the phase currents delivered to the load by the output phases. The controller is further operable to determine if the monitored phase currents indicate any of the individual output phases, any of the individual inductors or the output capacitor are faulty, even if the total current delivered to the load is within specified limits.

Abstract: A semiconductor device includes a voltage hold circuit that raises a second boosted voltage with rise of an output voltage of a booster circuit that generates a first boosted voltage and then maintains the second boosted voltage at a point when the output voltage reaches a hold voltage level after that, and a first switch that short-circuits a first output terminal through which the first boosted voltage is output and a second output terminal through which the second boosted voltage is output until the output voltage reaches the hold voltage level.

Abstract: An example method for controlling a circuit may include determining an input signal in a circuit, the input signal comprising distortion; determining a fundamental component of the input signal; determining an error of the input signal using the input signal and the fundamental component; determining a distortion metric using the error; and controlling the circuit as a function of the distortion metric.

Abstract: Systems and methods for relative phase detection and zero crossing detection for power line communications (PLC) are described. In some embodiments, both transmit and receive PLC devices detect a zero crossing on an AC mains phase. The devices start a phase detection counter (PDC) by generating a zero crossing pulse within 5% of the actual zero crossing time. When a frame is transmitted, the transmitting device includes a PDC value in the frame control header (FCH). The PDC value corresponds to the start time of the FCH. When the frame is received at the receive PLC device, the receive PLC device measures a local PDC value between the zero crossing and the start of the FCH. The receive device compares the local PDC value to the PDC value in the FCH of the received frame and determines if the devices are on the same phase.

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: A phase current estimator for a switching power converter includes analog circuitry for generating a phase current estimate error by comparing a phase current of the switching power converter to an analog representation of an estimate of the phase current. The phase current estimator further includes digital circuitry for revising the phase current estimate based on the phase current estimate error and a plurality of parameters associated with operation of the switching power converter. An estimator fault detection unit is provided for determining whether a difference between the phase current and estimate exceeds a threshold for indicating substandard phase current estimation.

Abstract: Phase detection between service nodes in a as “PRIME” (“PoweRline Intelligent Metering Evolution”) communications network, in which the service nodes are connected to one phase of a three-phase power distribution network. A service node joining a sub-network receives packet data units from other service nodes in the sub-network, including those that can potentially serve as a switch node to which the joining service node can register. The joining service node measures an elapsed time between a zero crossing of the AC power waveform at its phase and the start of a frame in the received packet data units. This elapsed time is compared with a similar zero crossing gap communicated by other service nodes in the packet data units, to identify the relative phases to which the two service nodes are connected.

Abstract: An example controller includes a measurement block and a drive block. The measurement block determines an amount of time that a dimmer circuit, that is coupled to an input of a power supply, disconnects an ac input voltage. The drive block generates a drive signal to control switching of a switch included in the power supply. The drive block operates a closed loop dimming control when the amount of time is less than or equal to a threshold and operates an open loop dimming control when the amount of time is greater than the threshold. The closed loop dimming control includes setting one or more operating conditions of the drive signal in response to a feedback signal that is representative of an output quantity of the power supply. The open loop dimming control includes holding the one or more operating conditions of the drive signal to a value.

Abstract: A power converter includes an energy transfer element and a power switch coupled the energy transfer element and an input of the power converter. A control circuit is coupled to generate a switching signal to control switching of the power switch in response to a feedback signal representative of an output of the power converter. A programming interface circuit is coupled to the control circuit and a coupling switcher coupled to the programming interface circuit. A programming terminal is selectively coupled to the programming interface circuit through the coupling switcher. A programming circuit coupled to the programming terminal is coupled to the programming interface circuit through the coupling switcher during a startup programming condition and during a fault condition of the power converter, and is decoupled from the programming interface circuit by the coupling switcher during a normal operating condition of the power converter.

Abstract: A controller may predict an estimated occurrence of a high-resistance state of a dimmer, wherein the high-resistance state occurs when the dimmer begins phase-cutting an alternating current voltage signal. The controller may also be configured to operate in a trailing-edge exposure mode for a period of time wherein the period of time includes a time of the estimated occurrence of the high-resistance state in order to allow the controller to detect the occurrence of the high-resistance state, wherein energy is transferred from an input to a dissipative element during the trailing-edge exposure mode. The controller may further be configured to minimize a time between a beginning of the period of time and the estimated occurrence of the high-resistance state by modifying the period of time based on an estimated charging time of a capacitor of the dimmer.

Abstract: An image forming apparatus that heat-fixes a toner image onto a recording sheet passing through a fixing nip formed by pressing a pressurizing member against a heating rotational body heated by a heater, comprising: a storage unit storing a basic power consumption level of the heater determined in advance in a situation where inflow of inrush current to the heater is not occurring; an estimation unit calculating an estimated power consumption level of the heater by estimating an increase in the power consumption level, with respect to the basic power consumption level, brought about by inflow of inrush current to the heater; and an output unit outputting the estimated power consumption level. The heater switches between a heating state of receiving power supply and a non-heating state of not receiving power supply. The increase is estimated according to a duration of a non-heating state immediately preceding the heating state.

Abstract: A power saving arrangement for use with a phase cut dimmer, the power saving arrangement constituted of: a power converter arranged to convert a received alternating current power signal to a direct current signal; a detector arranged to detect the presence, or absence, of the phase cut dimmer blocking a portion of an alternating current mains power sine wave from reaching the power converter; and a controllable minimum holding current circuit in communication with the received alternating current power signal, the controllable minimum holding current circuit responsive to an output of the detector, wherein in the event that the detector detects the absence of the phase cut dimmer, the controllable minimum holding current circuit is disabled such that a minimum holding current is not provided.

Abstract: A high-voltage (HV) startup device is disclosed. The HV startup device is connected with a control circuit of a switching power supply and receives a high voltage to provide and increase a triggering voltage received by the control circuit, wherein the control circuit is a pulse width modulator (PWM) or a pulse frequency modulator (PFM). When the triggering voltage reaches to a preset voltage of the control circuit, the control circuit sends out a control signal and the switching power supply uses the control signal to generate a sense signal. The HV startup device receives the control signal or the sense signal to stop providing the triggering voltage.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A charge pump includes: a first diode that is connected to a first node; a second diode that is connected to a second node; a pump capacitor that is connected to a third node to which the first diode and the second diode are connected; a power supply capacitor that is connected to the pump capacitor; a third diode that is connected between the pump capacitor and the power supply capacitor; and a zener diode that is connected in parallel to the third diode and the power supply capacitor. A power supply device decreases a ripple of an output current using a ripple reduction signal.

Abstract: A DC-DC converter includes: an error amplifier for outputting an error between an output voltage and a predetermined voltage; a phase compensation impedance element for accumulating the error across one end to generate an error phase; a determination unit for determining whether the voltage output by the error amplifier is higher, or lower than a reference voltage that is consonant with the predetermined voltage, and outputting a determination signal indicating determination results; and a voltage setting unit for setting a voltage for one end of the phase compensation impedance element higher than a lower output voltage limit for the error amplifier when the determination signal indicates that the voltage output by the error amplifier is lower than the reference voltage, or for canceling setting of the voltage when the determination signal indicates that the voltage output by the error amplifier is higher than the reference voltage.

Abstract: A universal load control module may include a power supply that operates over a wide voltage range, a microcontroller, and one or more functional control blocks. A functional control block may include a dimmer circuit for controlling a lighting load that provides reverse phase cut mode dimming, forward phase cut mode dimming, and hybrid phase cut mode dimming, as well as thermal protection. One or more universal control modules may be housed in a cabinet that include a cabinet control module. The cabinet may include additional thermal protection measures.

Abstract: An electronic system includes a controller that controls switching in a switching power converter in accordance with a dynamically determined, minimum line voltage switching threshold based on one or more operating parameters of the electronic system. In at least one embodiment, the one or more operating parameters of the electronic system include power utilization of a load. The controller utilizes the dynamically determined, minimum line voltage switching threshold to determine when to enable and disable switching in the switching power converter. Since the controller bases determination of the dynamically determined, minimum line voltage switching threshold on power utilization of the load, the controller operates more efficiently by reducing switching losses while still meeting power demand by the load.

Abstract: A power control circuit and method of formation is provided, which in one embodiment includes a low voltage detection circuit to process a rectified input voltage from at least one alternating current (AC) voltage source and to output a low voltage indication signal upon detection of an initiation of an increase in the rectified input voltage; and a driver circuit configured to receive a signal representative of the low voltage indication signal and, in response, to output a drive signal to the switch control input of the power switch to turn on the power switch.

Abstract: A method is provided in one example embodiment and includes computing energy usage associated with a domain that includes a plurality of endpoints; identifying particular endpoints of the plurality of endpoints that are capable of switching from a first power source to a battery power source; and communicating a broadcast message to the particular endpoints to switch to their corresponding battery power source.

Abstract: A voltage divider circuit is provided that automatically and dynamically adjusts its voltage divider chains as a supply voltage changes. The voltage divider circuit includes a plurality of voltage divider branches having different divider factors to divide the supply voltage and obtain a divided supply voltage. Additionally, a control circuit is coupled to the plurality of voltage divider branches and adapted to automatically monitor the supply voltage and dynamically select a voltage divider branch from among the plurality of voltage divider branches to maintain a selected divided supply voltage within a pre-determined voltage range.

Abstract: One embodiment of an impedance stabilizer for use with a switching voltage regulator supplied by a source of an electrical voltage has an impedance and a switch controllable to permit current from a source to flow through the impedance. Control circuitry to operate the switch cyclically with a controlled duty cycle is responsive to variations in the voltage of the source having a frequency lower than a cycle rate of the switch to increase the duty cycle of the switch as the voltage of the source increases.

Abstract: A circuit for generating a D.C. signal for controlling an A.C. switch referenced to a first potential, from a high-frequency signal referenced to a second potential, including: a first capacitive element connecting a first input terminal, intended to receive the high-frequency signal, to the cathode of a rectifying element having its anode connected to a first output terminal intended to be connected to a control terminal of the switch; and a second capacitive element connecting a second input terminal, intended to be connected to the second reference potential, to a second output terminal intended to be connected to the first reference potential, a second rectifying element connecting the cathode of the first rectifying element to the second output terminal.

Abstract: A switching power supply includes a switch and a controller for dimming control of the switching power supply. The controller includes a phase angle measurement block and a drive logic block. The phase angle measurement block is coupled to receive an input sense signal. The phase angle measurement block generates a phase angle signal representative of a phase angle of an input voltage of the power supply in response to the input sense signal. The drive logic block is coupled to control switching of the switch. The drive logic block controls the switch in a closed loop dimming control when the phase angle is less than or equal to a phase threshold and in a open loop dimming control when the phase angle is greater than the phase threshold.

Abstract: A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to provide the phase control signal in the forward phase-control mode to the electrical load.

Abstract: Switch-mode power conversion system and method thereof. The switch-mode power conversion system includes a primary winding configured to receive an input voltage, and a secondary winding coupled to the primary winding and configured to, with one or more other components, generate an output signal. Additionally, the switch-mode power conversion system includes a feedback component configured to receive the output signal and generate a feedback signal based on at least information associated with the output signal, and a voltage detector configured to receive the input voltage and output a detection signal. Moreover, the switch-mode power conversion system includes a mode controller configured to receive the detection signal and the feedback signal and generate a switch signal based on at least information associated with the detection signal and the feedback signal, and a switch configured to receive the switch signal and affect a first current flowing through the primary winding.

Abstract: Exemplary apparatus and associated methods involve a bypass module for modulating conductivity of one or more current paths to provide a first set of LEDs that are conducting near minimum output illumination and having a larger conduction angle than that of a second set of LEDs that conduct at a maximum output illumination. In an illustrative example, the conductivity of a bypass path in parallel with a portion of the second set of LEDs may be reduced while the AC input excitation is above a predetermined threshold voltage or current. The bypass path may be operated to provide a reduced effective turn-on voltage while the input excitation is below the predetermined threshold. For a given maximum output illumination at a maximum input excitation, the bypass module may control current through selected LEDs to construct an input current waveform with substantially improved power factor and reduced harmonic distortion.

Abstract: In various embodiments, a power supply device for light sources may include a feed line from mains via a phase-cut dimmer, selectively switchable between a conductive state and a non-conductive state, to permit or interrupt feeding of the device from mains. The device may include a power stage to feed at least one light source from said feed line from mains; a drive stage for said power stage; and a supply stage for said drive stage, said supply stage connected to said feed line from mains. The device may further include a sensor to detect when said dimmer is non-conductive and when said dimmer is conductive. The drive stage may be coupled to the sensor to disable driving of said power stage when the sensor indicates that the dimmer is non-conductive, and enable driving of the power stage when the sensor indicates that the dimmer is conductive.

Abstract: An image forming apparatus includes a fuser that fuses a paper medium and a fuser control device that controls an AC power supplied to the fuser. The fuser control device includes a phase detecting device that receives an AC voltage, detects zero-crossing points of the AC voltage, outputs a phase detecting signal when the zero-crossing points are detected, and selectively cuts off a flow of AC power into the phase detecting device in response to a mode control signal, a signal generator that generates a phase control signal to control a phase of the AC power supplied to the fuser based on the phase detecting signal, and a temperature controller that controls a temperature of the fuser by controlling the phase of the AC power supplied to the fuser according to the phase control signal.

Abstract: The regulating method is employed in a polyphase rotating electrical machine operating as a generator and having an excitation coil (10). The method is of the type in which a DC voltage (B+) is slaved to a predetermined setpoint, the voltage being produced by rectifying an AC voltage generated by the machine by controlling the duty cycle of a periodic excitation current (+EXC,?EXC) by means of a microcontroller (11), or the like, as a function of sampled values of the DC voltage (B+). The duty cycle is determined by the microcontroller (11) twice during an excitation current cycle (+EXC, ?EXC).

Abstract: An LED drive circuit in which an alternating voltage is input and an LED is driven, and which can be connected to a phase control dimmer The LED drive circuit is provided with an edge detector for detecting an edge of the output voltage of the phase control dimmer; and a current extractor for extracting a current from a current feed line for feeding an LED drive current to the LED; wherein the value of the current extracted from the current feed line by the current extractor is varied in accordance with the detection results of the edge detector.

Abstract: A voltage converter circuit can include a boost converter having a switching transistor and configured to receive an input voltage, produce an output voltage and selectively operate in one of a boost mode, a skip mode and a linear mode. In the boost and skip modes, the boost converter can switch on and off the switching transistor at a switching frequency to produce an output voltage at magnitudes greater than input voltage magnitudes. In the linear mode, the boost converter can turn off the switching transistor at all times to pass the input voltage unboosted to produce an output voltage at magnitudes less than input voltage magnitudes.

Abstract: This invention relates to a controller, more particularly, to a controller for driving a power transistor for obtaining improving impedance matching. An embodiment of a flow chart is revealed for the operation of the controller. The controller has frequency modulation capability with Lenz current of a loop linking to the driven power transistor to function with, Miller effect cancelling capability to its driven power transistor and fault detecting capability by detecting the absence of a Lenz current of a loop linking to the driven power transistor to function with.