Abstract: Apparatus and methods for bypassing an inductor of a voltage converter are provided. In one embodiment, a voltage converter includes an inductor and a bypass circuit that selectively bypasses the inductor based on a state of a bypass control signal. The inductor includes including a first end electrically connected to a first node and a second end electrically connected to a second node. The bypass circuit includes a first p-type field effect transistor and a second p-type field effect transistor electrically connected in series between the first node and the second node. The first p-type field effect transistor includes a body electrically connected to a first voltage, and the second p-type field effect transistor includes a body electrically connected to a second voltage greater than the first voltage.

Abstract: A power converter includes a first bus converter for converting a first direct current (DC) bus voltage into a first high frequency alternating current (AC) voltage and a second bus converter for converting a second high frequency AC voltage into a second DC bus voltage. A resonant circuit couples the first bus converter and the second bus converter. Further, a controller provides switching signals to the first bus converter and the second bus converter to operate the power converter in a soft switching mode. The controller includes a voltage detection circuit connected across at least one switching device of the power converter to detect a device voltage across the at least one switching device and a counter to count a number of hard switching detection pulses of the hard switching pulse signal detector.

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: A resonant converter, a power supply and a power controlling method thereof are provided. The power supply includes a resonant converter which includes a square wave generator configured to alternately turn on and off first and second switches according to a frequency to generate a square wave, a resonant wave generator configured to generate a resonant wave corresponding to the square wave and a rectifier configured to output a voltage corresponding to the resonant wave; and a controller configured to control a frequency modulation of the resonant converter, wherein the controller includes a variable switching circuit configured to increase the frequency of the resonant converter in response to the resonant converter entering a capacitive mode.

Abstract: In one embodiment, a dimmer circuit is coupled to an electronic load and receives an alternating current (AC) signal. A phase control circuit turns the dimmer circuit on for a first portion of the AC signal to turn on the electronic load. The dimmer circuit turns off during a second portion of the AC signal to turn off the electronic load. A switch is coupled to the phase control circuit. The switch is controlled to couple the phase control circuit to ground when the dimmer circuit is off where the switch is part of a power supply supplying power to the electronic load.

Abstract: A DC-DC converter includes a zero current detector. The DC-DC converter includes a high-side switch and a low-side switch. When the DC-DC converter works in a discontinuous conduction mode (DCM). The zero current detector detects a zero current a detection node which is arranged between the high-side switch and the low-side switch generates the zero current, the zero current detector outputs the control signal to a driver. The driver switches the high-side switch and the low-side switch off simultaneously according to the control signal.

Abstract: An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a power converter circuit that is electrically coupled to an electrical power source for receiving alternating current (AC) input power from the electrical source and delivering direct current (DC) output power to an electronic device. The power converter circuit includes a transformer and a switching device coupled to a primary side of the transformer for delivering power from the electrical power source to a primary side of the transformer. A controller is coupled to a voltage sensor and the switching device for receiving the sensed voltage level from the voltage sensor and transmitting a control signal to the switching device to adjust the voltage level of power being delivered to the electronic device.

Abstract: A control circuit varies the power of a load powered by an alternating voltage, comprising: a first thyristor and a first diode connected in antiparallel between first and second nodes, the cathode of the first diode being on the side of the first node; a second thyristor and a second diode connected in antiparallel between the second node and a third node, the cathode of the second diode being on the side of the third node; third and fourth diodes connected in antiseries between the first and third nodes, the cathodes of the third and fourth diodes being connected to a fourth node; a transistor between the second and fourth nodes; and a control unit for controlling the first and second thyristors and the transistor.

Abstract: A control device detects zero crossings of a current through a rectifier transistor during plural cycles; generates a turn-on signal of the transistor and inserts a turn-on delay equal to a fixed first quantity from the start time of for each cycle. The control device starts counting consecutive cycles after inserting the turn-on delay; detects whether a zero crossing of the current through the transistor after turning on said transistor has occurred; if no zero crossing is detected before counting a number N of consecutive cycles, decreases the turn-on delay by a fixed second quantity for the next cycle; if a zero crossing is detected, maintains turned on the transistor; if the turn-on delay is smaller than first quantity, increases the turn-on delay o for the next switching cycle; and if the turn-on delay is equal to the first quantity, maintains the turn-on delay for the next switching cycle.

Abstract: An embodiment of an apparatus, such as a circuit breaker, includes an input node, an output node, and a digital circuit. The input node is configured to receive an input voltage, and the output node is coupled to the input node and is configured to carry an output current. And the digital circuit is configured to uncouple the output node from the input node in response to a power drawn from the input node exceeding a threshold.

Abstract: Communication and charging circuitry for an implantable medical device is described having a single coil for receiving charging energy and for data telemetry. The circuitry removes from the AC side of the circuit a tuning capacitor and switch traditionally used to tune the tank circuitry to different frequencies for telemetry and charging. As such, the tank circuitry is simplified and contains no switchable components. A switch is serially connected to the storage capacitor on the DC side of the circuit. During telemetry, the switch is opened, thus disconnecting the storage capacitor from the tank circuit, and alleviating concerns that this capacitor will couple to the tank circuit and interfere with telemetry operations. During charging, the switch is closed, which allows the storage capacitor to couple to the tank circuitry through the rectifier during some portions of the tank circuitry's resonance.

Abstract: A control circuit includes an auxiliary pin for receiving an auxiliary voltage of an auxiliary winding of a power converter; a first detection unit for detecting a first time point when the auxiliary voltage begins resonance, and outputting a first detection signal according to the first time point; a second detection unit for detecting a second time point when the auxiliary voltage reaches a predetermined voltage, and outputting a second detection signal according to the second time point; a delay time controller for obtaining a delay time according to a output time difference between the first detection signal and the second detection signal, and outputting a driving signal with delay of the delay time when receiving the second detection signal; and a gate control signal generator for generating a gate control signal to a power switch of the power converter according to the driving signal of the delay time controller.

Abstract: A method for providing non-resonant zero-voltage switching in a switching power converter. The switching power converter converts power from input power to output power during multiple periodic switching cycles. The switching power converter includes a main switch and an auxiliary capacitor adapted for connecting to the main switch, and an inductor connectible to the auxiliary capacitor. When the main switch is on, a previously charged (or previously discharged) auxiliary capacitor is connected to the main switch with auxiliary switches. The main switch is switched off with zero voltage while discharging non-resonantly (charging) the auxiliary capacitor by providing a current path to the inductor. The auxiliary capacitor is disconnected from the main switch. The voltage of the auxiliary capacitor is charged and discharged alternatively during subsequent switching cycles.

Abstract: The present document relates to multiphase DC-DC power converters. In particular, the present document relates to the compensation of the phase offset incurred in multiphase DC-DC power converters which are controlled based on coil current zero crossing. A control circuit for a multiphase power converter is described. The multiphase power converter comprises a first and a second constituent switched-mode power converter, wherein the first and second constituent power converters provide first and second phase currents, respectively. The first and second phase currents contribute to a joint load current of the multiphase power converter. The first and second constituent power converters comprise first and second half bridges with first and second high side switches and first and second low side switches, respectively.

Abstract: A signal generation device and a signal generation method may measure leakage currents, such as an input current value I and phase-shifted current values I cos ? and I sin ? in a short period of time and automatically output the detected values without calculating a vector of a phase difference. The signal generation device generates logical signals from a voltage waveform and a current waveform of a measured power line through first and second comparators, sets parameters, full-wave rectifies the current waveform, and performs quantization transform on the full-wave rectified current waveform using a successive ??ADC.

Abstract: A semiconductor device includes: first and second switching elements connected in series through a switching node; a pulse control unit that pulse-controls switching operations of the first and the second switching elements; an inductor that outputs an output voltage from a second end, a first end of the inductor being coupled to the switching node; a detection unit that detects that an inductor current flowing through the inductor is zero; and a first determination unit that determines that an operation mode of an external circuit to which the output voltage is supplied is a second mode when a period during which the inductor current is zero is longer than a first reference period, a power consumption in the second mode being smaller than that in a first mode.

Abstract: A DC-DC converter includes a zero current detector. The DC-DC converter includes a high-side switch and a low-side switch. When the DC-DC converter works in a discontinuous conduction mode (DCM). The zero current detector detects a zero current a detection node which is arranged between the high-side switch and the low-side switch generates the zero current, the zero current detector outputs the control signal to a driver. The driver switches the high-side switch and the low-side switch off simultaneously according to the control signal.

Abstract: A power converter having a bootstrap refresh control circuit and a method for controlling the power converter. The bootstrap refresh control circuit is configured to monitor a bootstrap voltage across a bootstrap capacitor and to provide an enhanced high side driving signal to a high side switch of the power converter. The bootstrap refresh control circuit is further configured to controlling the charging of the bootstrap capacitor through regulating the on and off switching of the high side switch and a low side switch based on the bootstrap voltage. The bootstrap refresh control circuit can refresh the bootstrap voltage in time to support driving the high side switch normally, without causing large spikes in an output voltage of the power converter and without influencing the power conversion efficiency of the power converter.

Abstract: A signal generation device and a signal generation method may measure leakage currents, such as an input current value I and phase-shifted current values I cos ? and I sin ? in a short period of time and automatically output the detected values without calculating a vector of a phase difference. The signal generation device generates logical signals from a voltage waveform and a current waveform of a measured power line through first and second comparators, sets parameters, full-wave rectifies the current waveform, and performs quantization transform on the full-wave rectified current waveform using a successive ??ADC.

Abstract: Reducing current harmonics at light loads is disclosed. In an example, a method includes increasing output voltage of a boost converter to reach a higher potential in a low power mode. After reaching the higher potential, the method includes dropping a set point for the output voltage.

Abstract: The present invention relates to a quasi-resonant controlling and driving circuit and method for a flyback converter. In one embodiment, a controlling and driving circuit for a flyback converter, can include: a differentiation circuit configured to receive a third controlling signal and a drain-source voltage of a main power switch of the flyback converter; where the drain-source voltage is configured to be differentiated by the differentiation circuit to generate a differential voltage when the third controlling signal is active within an interval that the main power switch is shut-off; a valley voltage detection circuit coupled to the differentiation circuit, and configured to receive the differential voltage; and where a valley controlling signal is configured to be generated by the valley voltage detection circuit to achieve quasi-resonant driving for the main power switch of the flyback converter when the differential voltage crosses zero with a positive slope.

Abstract: A switching regulator has an output stage which, with an output switch element, an inductor, a rectifying element, and a smoothing element, generates an output voltage from an input voltage, a divided voltage generator which generates a divided voltage from a switch voltage generated at one terminal of the rectifying element, a selector which outputs one of the divided voltage and a fixed voltage in accordance with a switching signal as a select voltage, a zero-cross comparator which monitors the select voltage to generate a zero-cross detection signal, and a controller which generates the switching signal in accordance with the necessity of monitoring the zero-cross of an inductor current and which performs on/off control of the output switch element reflecting the zero-cross detection signal.

Abstract: An IGBT/FET-based energy savings device, system and method wherein a predetermined amount of voltage below a nominal line voltage and/or below a nominal appliance voltage is saved, thereby conserving energy. Phase input connections are provided for inputting analog signals into the device and system. A magnetic flux concentrator senses the incoming analog signal and a volts zero crossing point detector determines the zero volts crossing point of the signal. The positive half cycle and negative half cycle of the signal are identified and routed to a digital signal processor for processing the signal. The signal is reduced by pulse width modulation and the reduced amount of energy is outputted, thereby yielding an energy savings for an end user.

Abstract: A power conversion apparatus includes first, second, third, and fourth switching elements. In a first period, the second and third switching elements are switched ON, and first and fourth switching elements are alternately switched ON/OFF. In a second period, the first and fourth switching elements are switched ON, and the second and third switching elements are alternately switched ON/OFF. In a third period, the first and second switching elements are switched ON, and the third and fourth switching elements are switched OFF. The power conversion apparatus provides a release path for inductive energy accumulated in a reactor.

Abstract: A zero-crossing detector circuit includes: a first capacitor including a first electrode configured to connect to one end of an AC power supply and a second electrode; a second capacitor including a first electrode configured to connect to the other end of the AC power supply and a second electrode; a current path, which is connected in series between the second electrode of the first capacitor and the second electrode of the second capacitor, and which is connected to a reference potential, and which generates a second-electrode-side voltage when the AC current passes through the current path; a signal converting circuit, which is connected to the AC power supply to receive the second-electrode-side voltage and then converts the second-electrode-side voltage into a pulse signal; and a detecting unit, which detects a pulse period of the pulse signal, which and detects zero-crossing points by using the pulse period.

Abstract: An electronic circuit and method for sampling negative coil current in a power converter includes a zero crossing detector and a sample-and-hold circuit. A switch determines whether a charging or discharging current is flowing through a coil.

Abstract: A control circuit of a power converter includes: a zero current detection circuit for detecting a current flowing between an inductor and a voltage output terminal of the power converter to generate a zero current detection signal; an adjusting circuit for generating an adjustment signal according to the zero current detection signal; a clock signal generating circuit for adjusting a frequency of a clock signal according to the adjustment signal; a periodical signal generating circuit for generating a periodical signal according to the clock signal; an error detection circuit for generating an error signal; and a control signal generating circuit for generating a control signal to control operations of a power switch. If the and amount of pulses generated by the zero current detection circuit satisfy a predetermined condition, the adjusting circuit switches the power converter's operation mode from DCM to CCM.

Abstract: An image forming apparatus includes a heat source of a fixing device to heat when an alternate current signal is supplied thereto; a conduction control circuit for controlling an alternate current power source with a conduction control signal, and for supplying the alternate current signal to the heat source; and a control unit for outputting the conduction control signal in a specific pattern. The conduction control circuit includes a conduction control element for switching between conduction and non-conduction at a zero cross timing of the alternate current power source according to the conduction control signal, and for supplying the alternate current signal.

Abstract: Various embodiments of the present invention provide for an adaptive and accurate zero cross circuit that can operate without directly sensing an inductor current. Certain embodiments allow adjustment of a zero crossing condition while eliminating the need for a blanking time. In certain embodiments this is accomplished by detecting the effects of turning off a switch on a switching node voltage of a buck converter. Some embodiments use a counter to lengthen or shorten the delay time between an inductor crossing a zero value and the effect of the switching event. In one embodiment, the effect of the switching event includes a change in the direction of the switching node voltage from which the direction of a current flowing in the buck converter inductor.

Abstract: Disclosed are driving control methods and circuits for quasi-resonant control of a main power switch of a switching power supply. In one embodiment, a driving control circuit can include: (i) a clamp circuit coupled to a gate of the main power switch, where the clamp circuit is configured to clamp a voltage of the gate to a clamping voltage that is greater than a threshold voltage of the main power switch; (ii) a valley voltage detection circuit configured to activate a valley control signal when a drain-source voltage of the main power switch is at a resonance valley level; and (iii) a source voltage control circuit configured to reduce a voltage of a source of the main power switch to turn on the main power switch in response to the valley control signal being activated.

Abstract: The present invention relates to a switch control circuit, a switch control method, and a converter using the same. An input voltage rectified from an AC input in a converter is transmitted to an inductor, and output power is generated from an inductor current by the input voltage. The converter includes a power switch connected to the inductor to control the inductor current and a sense resistor having a first end connected to a ground and a second end connected to the AC input. At a time point that a sense voltage generated in the sense voltage reaches the peak point and then decreased to an on-reference voltage, the power switch is turned on. The on-reference voltage is a sense voltage at a resonance start time point between a parasite capacitor of the power switch and the inductor.

Abstract: The present invention relates to a switch controller and a converter including the same. The switch controller generates an oscillating voltage determining a switching frequency alternately switching a high-side switch and a low-side switch, senses a power source voltage supplied to the switch controller, and maintains the high-side switch and the low-side switch in the turn-off state in a case that the change of the power source voltage is not generated after one of the high-side switch and the low-side switch is turned off according to the oscillating voltage.

Abstract: A resonance-based DC-DC converter for converting a DC input voltage to a first DC output voltage (VOUT1) on a output conductor (9) includes an inductor (L) having a first terminal connected to a source (2) of a DC input voltage (VIN) and a second terminal coupled to a first conductor (4) and a capacitor (CRES) having a first terminal coupled to the first conductor. A first switch (SW1) is coupled between the resonance conductor and the output conductor to conduct inductor current (IL) into the output conductor during a first phase (Phase1). A second switch (SW2) is coupled between a second terminal of the capacitor and the output conductor to conduct inductor current through the capacitor into the output conductor (9) during a second phase (Phase2).

Abstract: A switching loss is reduced by reducing a deviation from the operational principle of zero-volt switching (ZVS). A semiconductor integrated circuit includes high-side switch elements Q11 and Q12, a low-side switch element Q2, and a controller CNT. A decoupling capacitance Cin is coupled between one end of a high-side element and an earth potential, and the high-side element includes the first and second transistors Q11 and Q12 coupled in parallel. In changing the high-side elements from an on-state to an off-state, CNT controls Q12 from an on-state to an off-state by delaying Q12 relative to Q11. Q11 and Q12 are divided into a plurality of parts inside a semiconductor chip Chip 1, a plurality of partial first transistors formed by dividing Q11 and a plurality of partial second transistors formed by dividing Q12 are alternately arranged in an arrangement direction of Q11 and Q12, inside the semiconductor chip Chip 1.

Abstract: The present invention provides a controller for a power converter. The controller comprises a PWM circuit, a detection circuit, a signal generator, an oscillation circuit, a valley-lock circuit, a timing circuit and a burst circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to control and disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a waveform obtained from the transformer. The signal generator is coupled to receive the feedback signal and the valley signal for generating an enabling signal. The oscillation circuit generates a maximum frequency signal. The maximum frequency signal associates with the enabling signal to generate a turning-on signal. The turning-on signal is coupled to enable the switching signal. A maximum frequency of the turning-on signal is limited.

Abstract: The synchronous switching power converter comprises an inductor; a down bridge transistor; and a zero current detection circuit comprising a zero current comparator for receiving a fixed comparing level at a negative input end for comparison to change state of a comparing result; a delay unit, for delaying the comparing result to change state of a turn off signal according to a compensation voltage, to turn off the down bridge transistor when determining current on the inductor is zero; a transient state adjusting circuit for indicating a transient period when detecting state of the turn off signal is changed; and an integrator for integrating the compensation voltage by analog manner to adjust value of the compensation voltage and providing to the delay unit within the transient period; wherein the zero current comparator determines the integrator to integrate positively or negatively within the transient period.

Abstract: The invention relates to an electrical power tool, particularly an electric hand power tool, for operating with alternating current, having an electric motor, and electronic control device, and an electrical power switch for actuating the electric motor, wherein the electronic control device comprises a bias voltage output and a detection input, connected to each other by means of a voltage divider comprising a summation point and to the side of the power switch facing the electric motor, and the control device is further designed such that the potential at the detection input is monitored after actuating the power switch and used for checking whether the power switch is conducting, and that it is actuated again if the power switch was not conducting or returned to the non-conducting state during the monitoring, and that said checking and any renewed actuation of the power switch is repeated within a half-wave of the alternating voltage.

Abstract: A zero voltage switching (ZVS) technique for use in isolated and non-isolated switching power converters and regulators, e.g. based upon buck, boost, buck-boost, and double-clamped topologies is disclosed. During a reverse energy phase of the converter operating cycle, energy is transferred in reverse from the load or the clamp capacitor to the inductor, allowing the current in the inductor to increase in magnitude with a reverse polarity, building up reverse energy. The reverse energy may be used for charging and discharging parasitic and other circuit capacitances for ZVS. The reverse energy phase is adjusted based upon circuit operating conditions, so that the amount of energy stored in the inductor L at the end of the reverse energy phase is approximately equal to, but preferably no greater than, that required to turn the switches ON at substantially zero voltage. Thus full ZVS may be achieved under a wide variety of operating conditions without incurring unnecessary losses.

Abstract: A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

Abstract: Embodiments of the invention relate generally to power management and the like, and more particularly, to an apparatus, a system, a method, and a computer-readable medium for providing power controlling functionality to generate configurable power signals and to deliver power during fault conditions. In at least some embodiments, a power control unit can generate power signals having configurable attributes as a function of a mode of operation, a fault type, and the like.

Abstract: A boost regulator is provided that has increased efficiency. The increased efficiency is provided by incorporating a sensing circuit that senses when the current in the boost regulator's inductor is near zero or when the voltage at its switching node is near zero or virtual ground. A switching signal is provided to the boost regulator's switching transistor when the near zero current or voltage is sensed. Switching at the near zero current or voltage moment (the “critical conduction moment”) helps to eliminate or minimize the power loss associated with switching the transistor at a time other than during the critical conduction moment.

Abstract: A switching power supply device includes: a non-linear control type switching control unit that, in accordance with a result of a comparison between a feedback voltage and a reference voltage, performs on/off control of a switch element, and thereby generates an output voltage from an input voltage; a backflow current detection unit that, upon detecting a backflow current flowing to the switch element, forcibly switches off the switch element; and an on-time setting unit that sets an on-time of the switch element, in a case of the backflow current not being detected, in accordance with a duty of the switch element, and in a case of the backflow current being detected, in accordance with a switch voltage appearing at one end of the switch element or the output voltage.

Abstract: Aspects of the invention include a switching power supply device that includes a zero current detecting circuit that detects zero current of electric current flowing through the inductor to turn ON the switching element, an ON width generating circuit that determines the ON width of the switching element to turn OFF the switching element, and an OFF width detecting circuit that detects the OFF width of the switching element based on the output of the ON width generating circuit and the output of the zero current detecting circuit, and holds the OFF width until the next operating cycle. Aspects of the invention also include an ON width adjusting circuit that is included in the ON width generating circuit and adjusts the ON width of the switching element in the next operation cycle according to the width detected by the OFF width detecting circuit.

Abstract: The present invention relates to a power factor correction circuit and a driving method thereof. The power factor correction circuit includes a power switch controlling an inductor current flowing in an inductor, an auxiliary inductor coupled to the inductor with a predetermined turn ratio, and a power factor correction controller controlling output power by controlling a switching operation of the power switch. The power factor correction controller determines whether or not an output voltage of the output power is an over-voltage by using the sum of a source current and a sink current that control a zero current detection voltage to be included within a predetermined clamping range, the zero current detection voltage corresponding to an auxiliary voltage that is a both-end voltage of an auxiliary inductor.

Abstract: In a switching power source of a flyback converter system according to the present invention, large electric power can be applied, by reducing loss of a switching element, a coil, and an output smoothing circuit, input voltage is applied to a primary coil of a transformer, and switching drive of the input voltage is carried out by a switching element, so that direct-current electric power is outputted from a secondary coil of the transformer through a rectifier circuit. The power source apparatus includes a trigger-control circuit which detects direct-current output voltage to control an “on” period, detects that current of the secondary coil becomes zero based on a voltage signal from a control coil, and turns on the switching element, and a timer circuit which is operated according to the voltage signal of the control coil, and gives an ON signal to the trigger-control circuit according to a timing signal.

Abstract: A sequential switching shunt regulator cell comprising: a power line (PL) for connecting a power source (SA) to a power bus (PB); a shunting (SSW) switch for shunting said power line; and driving means (DM) for opening or closing said shunting switch depending on an error signal (MEA) indicative of a voltage level of said power bus; characterized in that it also comprises: a non-redundant rectifier (D3) connected in series to said power line for disconnecting the power bus from the shunting switch when the latter is closed; and a fault detector (FD) for detecting a short-circuit fault condition of said non-redundant rectifier, and for opening the shunting switch in reply to said condition. Advantageously, the rectifier can be a synchronous rectifier. A solar power regulator comprising a plurality of solar arrays connected to a power bus through respective sequential switching shunt regulator cells of the kind described above.

Abstract: A power detection regulation device including a power detection signal generator, a power state detector and a regulated output unit is disclosed. The power detection signal generator receives the input power from an external power supply and generates a power detection signal. The power state detector generates a power state signal based on the power state derived from the power detection signal. The regulated output unit receives the power state signal and generates a driving signal to an external electrical device in accordance with the feedback signal from the external electrical device. The power state signal is provided for the external electrical element to perform relevant processes, and the regulated output device can output the predetermined driving signal on receiving the power state signal indicating some abnormal situation in the input power so as to maintain the normal operation performed by the actuating element in the external electrical device.

Abstract: A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

Abstract: The present invention relates to a protection circuit, a resonance converter having the same, and a protection method thereof. A resonance converter having high-side and low-side switches senses a current flowing through the low-side switch and determines a zero voltage switching failure by using a width of a current flowing to a negative direction of the low-side switch.

Abstract: A switch controller for switching power supply is coupled to an auxiliary winding of the switching power supply through a detecting resistor. The switch controller provides a detecting current passing through the detecting resistor for keeping the voltage level of a detecting signal transmitted by the detecting resistor higher than a predetermined voltage. In this way, the switch controller can avoid the latch-up phenomenon caused by receiving the detecting signal of the negative voltage level. In addition, the switch controller can detect the magnitude of an input voltage of the switching power supply by means of the detecting current, and accordingly control the operation of the switching power supply.