Abstract: A compensation circuit and a compensation method for providing compensation of a power converter are proposed. A current sense circuit is coupled to receive a switching current for generating a current signal. A signal generation circuit is developed to generate a first compensation signal and a second compensation signal for adjusting the current signal. The first compensation signal is coupled to adjust the current signal for the output power limit of the power converter. The second compensation signal is coupled to adjust the current signal for the slope compensation. The slope of the first compensation signal is decreased when the power transistor is turned on. The slope of the second compensation signal is increased in response to the turn on of the power transistor.

Abstract: There is provided an inverter device capable of simplifying the circuit structure, lowering the cast, and downsizing of the device. The inverter device detects a switching change of an inverter by a pulse and is equipped with a pulse signal detector capable of detecting a motor residual voltage or a phase and a detector for detecting a residual voltage or a phase. The inverter device includes a voltage detector, a circuit for detecting a pulse signal based on a comparison between a phase voltage detection value per one phase output from the voltage detector and a first reference voltage value, a circuit for detecting a line residual voltage based on phase voltage detection values of two phases output from the voltage detector, and a circuit for detecting a line phase based on a comparison between the line residual voltage and a second reference voltage value.

Abstract: Systems, methods, and apparatus for supplying AC power to an AC power grid from a DC power source, such as a photovoltaic (PV) array are disclosed. The systems and methods can include a converter coupled to the DC power source that provides DC power to a DC bus at a DC bus voltage. The systems and methods can further include an inverter coupled to the DC bus for converting the DC power of the DC bus to an output AC power. The systems and methods can further include a control system configured to regulate the DC bus voltage of the DC bus to operate at a variable DC bus voltage setpoint. The control system can adjust the DC bus voltage setpoint based at least in part on the DC bus voltage and the output AC current of the inverter.

Abstract: An example controller for a power converter according to aspects of the present invention includes a switching control that switches a power switch to regulate an output of a power converter. The controller also includes a sensor coupled to receive a signal from a single terminal of the controller. The signal from the single terminal is representative of a line input voltage of the power converter during at least a portion of an on time of the power switch. The signal from the single terminal is also representative of an output voltage of the power converter during at least a portion of an off time of the power switch. The switching control is responsive to the sensor.

Abstract: A controller for use in a power converter to detect changes in output voltage. An example controller includes a drive circuit to generate a switching signal. The switching signal is coupled to be received by a power switch to be coupled to an energy transfer element and an input of the power converter to control a transfer of energy from the input of the power converter to an output of the power converter. An output voltage sensor is coupled to the drive circuit and coupled to receive a feedback signal representative of the output of the power converter. The output voltage sensor includes first and second pulse sampler circuits. The first pulse sampler circuit is coupled to capture a first peak voltage representative of a second peak of a ringing voltage of the feedback signal at a first time in the feedback signal.

Abstract: The present invention mainly discloses low power non-isolated driver that can be used for LED lighting and other non-isolated power supply appliance, in which the input side is connected to an AC or DC input, a PWM control circuit is connected to the buck converter switch, a capacitor filters the output voltage ripple and an output voltage/current control circuit provides feedback signal to the PWM control circuit. The present invention has such features of less component number, low total cost, high reliability, and better line/load regulation.

Abstract: A supplying power adjusting apparatus has excellent temperature response and excellent stabilities to power supply change and load change. The apparatus is provided with a semiconductor inverter for high-speed switching power control, which converts a direct current rectified by a rectifying circuit (10) into alternating current power in response to a control signal and supplies a heater (7) with the power; a temperature change detecting circuit (24) for detecting the temperature change of the heater (7); a power supply change detecting circuit (22) for detecting the power change of the rectifying circuit (10); a load change detecting circuit (23) for detecting the change of the alternating current power supplied to the heater (7); and a power control signal generating circuit (15) which calculates a power quantity to be supplied to the heater (7) and controls the frequency or duty ratio of a control signal to be added to the power controlling semiconductor inverter in response to the calculated results.

Abstract: A power supply device includes a first switching element, a second switching element, a transformer having a primary coil, a low-pass filter including an input port connected to the secondary coil, an output terminal connected to an output port of the low-pass filter, a detector for outputting a voltage that follows a voltage at the output terminal, a reference signal generator for generating a reference voltage, a comparator unit for outputting a signal based on a result of comparison between the voltage supplied from the detector and the reference voltage, and an operation pause circuit controlling the first and second switching elements. The operation pause circuit is operable to drive the first and second switching elements according to the signal output from the comparator unit, and to cause the first and second switching elements not to conduct regardless of the signal output from the comparator unit.

Abstract: A method and apparatus for generating AC power. In one embodiment, the apparatus comprises a DC/AC inversion stage capable of generating at least one of a single-phase output power, a two-phase output power, or a three-phase output power; and a conversion control module, coupled to the DC/AC inversion stage, for driving the DC/AC inversion stage to selectively generate the single-phase output power, the two-phase output power, or the three-phase output power based on an input power to the DC/AC inversion stage.

Abstract: A resonant converter is provided which may be used for supplying power to the primary conductive path of an inductively coupled power transfer (ICPT) system. The converter includes a variable reactive element in the resonant circuit which may be controlled to vary the effective inductance or capacitance of the reactive element. The frequency of the converter is stabilised to a nominal value by sensing the frequency of the converter resonant circuit, comparing the sensed frequency with a nominal frequency and varying the effective inductance or capacitance of the variable reactive element to adjust the converter frequency toward the nominal frequency.

Abstract: An isolating circuit for a DC/AC converter includes an input, an output, an energy storage element and a switch element. The DC/AC converter includes an energy storage isolated from mains during a freewheeling phase. The output of the isolating circuit is configured to be connected to the DC/AC converter, and the energy storage element is connected to the input and serves for storing energy received from the input. The switching element is connected between the energy storage element and the output of the isolating circuit and is operative to connect the energy storage element to the output during the freewheeling phase, and to isolate the energy storage element from the output outside the freewheeling phase of the DC/AC converter.

Abstract: A circuit with an isolation interface and a remote on/off function is disclosed. The circuit includes a controller included in a primary side of the circuit. The controller is coupled to receive a primary side feedback signal and the controller is configured to enter a shutdown mode when the primary side feedback signal exceeds a feedback signal threshold. The circuit also includes an isolation interface coupled to galvanically isolate the primary side from a secondary side of the circuit. The isolation interface translates a secondary side feedback signal from the secondary side into the primary side feedback signal on the primary side. The isolation interface is configured to adjust the primary side feedback signal to exceed the feedback signal threshold in response to an on/off signal.

Abstract: A converter and a driving method thereof are provided. The converter includes first and second switches, and generates a square wave signal according to operations of the first and second switches. The converter includes a first capacitor and a primary coil, and resonates a driving voltage by using a driving voltage with the first capacitor and the primary coil so as to generate a driving current. The converter includes a secondary coil that forms the primary coil and the transformer, and generates output power by rectifying a current and a voltage generated in the secondary coil. In addition, the converter detects the phase of the driving current, and increases switching frequencies of the first and second switches if a phase difference of the phase of the driving current and that of the driving voltage is smaller than a predetermined value.

Abstract: A heating device for an inductive cooking device is provided and includes a first resonant circuit, with at least one first and one second inductor, for the transmission of heat energy to a heating element for heating thereof and a first circuit for energising the first resonant circuit and introduction of the heat energy to the inductors. Differing cooking containers may be effectively heated, whereby the heating device has a switching device by which the heating energy is selectively supplied to only one of the inductors or simultaneously to both inductors in a parallel circuit.

Abstract: A driving circuit includes a generation unit configured to generate a driving signal for turning on and off a power switching device, the driving signal having plural levels of voltage at which the power switching device is turned on. The driving circuit also includes a switching control unit configured to switch between the plural levels of voltage at which the power switching device is turned on, depending on a status of the power switching device.

Abstract: A controller for a power converter is disclosed. An example circuit controller according to aspects of the present invention includes an input voltage sensor to be coupled to receive an input signal representative of an input voltage of the power converter. A current sensor is also included and is to be coupled to sense a current flowing in a power switch. A drive signal generator is to be coupled to drive the power switch into an on state for an on time period and an off state for an off time period. The controller is coupled to adjust a duty cycle of the power switch in response to a difference between a time it takes the current flowing in the power switch to change between two current values when the power switch is in the on state and a control time period.

Abstract: In one embodiment, a power converter system comprises an input terminal operable to connect to a DC power source and an output terminal at which an output voltage can be provided. An active clamped forward converter is operable to provide forward power flow from the DC power source to the output terminal. A flyback converter is operable to provide backward power flow from the output terminal to the DC power source. The active clamped forward converter and the flyback converter cooperate to generate a rectified sinusoidal waveform at the output terminal.

Abstract: The present invention discloses a charger control circuit and a charger control method for controlling a charger having a transformer, the transformer including a primary winding and a secondary winding. The charger control circuit comprises: a power switch coupled to the primary winding; a switch control circuit controlling the operation of the power switch; and a detection circuit which generates a signal according to a voltage at a node between the power switch and the primary winding, and supplies the signal to the switch control circuit.

Abstract: A power conditioner of a photovoltaic system is configured operate at higher accuracy. A chopper circuit, a capacitor connected in parallel to the chopper circuit, and a control circuit that controls an ON/OFF status of switch elements in the chopper circuit to control charging and discharging of the capacitor are provided. The control circuit includes a measurement control section that measures an inter-end voltage of the capacitor and a control circuit section that performs a predetermined control operation from a measurement output of the measurement circuit section. The measurement circuit section includes a differential amplifier circuit that differentially amplifies the inter-end voltage of the capacitor. The circuit control section calibrates an in-phase component in the output of the differential amplifier circuit as an in-phase error and performs the control from the calibrated output from the differential amplifier circuit.

Abstract: A power supply regulator including a variable current limit threshold that increases during an on time of a switch. In one aspect, a power supply regulator includes a comparator coupled to receive a signal representative of a current through a switch during an on time of the switch. The comparator is further coupled to receive a variable current limit threshold that increases during the on time of the switch. The power supply regulator also includes a feedback circuit coupled to receive a feedback signal representative of an output of a power supply. A control circuit is also included and is coupled to the switch, to an output of the comparator, and to an output of the feedback circuit. The control circuit is coupled to control a switching of the switch in response the output of the comparator and the output of the feedback circuit to regulate the output of the power supply.

Abstract: A switching power conversion circuit includes a power circuit, a feedback circuit and a control circuit. The power circuit includes a switching circuit and a first magnetic element. The first magnetic element generates a magnetic flux change by alternately conducting or shutting off the switching circuit, so that an input voltage is converted into the output voltage by the power circuit. The feedback circuit generates a feedback signal according to the output voltage. The control circuit is used for controlling an on duration and an off duration of the switching circuit, thereby maintaining the output voltage at a rated voltage. The off duration of the switching circuit is maintained at a constant interval under control of the control circuit. The on duration of the switching circuit is adjusted to be a specified interval smaller than a maximum on duration according to the magnitude of the input voltage.

Abstract: A power supply device of controlling feedback synchronization is connected to an electric power source for obtaining an input power and includes first and second converters for modulating the input power. The first and second converters include first and second output terminals for providing first and second output power respectively. The power supply device further includes a feedback synchronization unit electrically coupled to the first and second output terminals of the first and second converters for obtaining first and second feedback signals, and producing and transmitting a synchronous feedback signal to the second converter according to a voltage difference of the first and second feedback signals to synchronizing output voltage level of the second converter with the first converter. The aforementioned circuit can control the synchronization of a voltage boost time and output time of the first and second converters.

Abstract: The present invention can include an image forming apparatus having an electrical load, a supplying circuit configured to supply an electrical power to the electrical load, and an output circuit configured to output a voltage according to a current value of the electrical power being supplied to the electrical load. The present invention may also provide for a controller configured to control an electrical current flowing in the electrical load based on an output voltage value of the output circuit as a feedback value, and an inhibiting circuit configured to inhibit a reverse current to flow in the output circuit when the supplying circuit is turned off.

Abstract: A switching control IC outputs a rectangular wave signal from an output terminal thereof to a driving circuit. A feedback circuit compares a value of a divided voltage of a voltage across output terminals of a switching power supply device with a reference voltage, generates a feedback signal, and inputs the feedback signal into a feedback terminal of the switching control IC. A capacitor and a Zener diode are connected between the feedback terminal and a ground terminal. The Zener diode is selectively connected, and a voltage at the feedback terminal is changed in accordance with the presence of the Zener diode. A voltage at the feedback terminal is detected, and one of a latch method and a hiccup method is selected as a method for an overcurrent protection operation in accordance with the detected voltage.

Abstract: A ripple voltage suppression apparatus includes a DC/DC converter and a control circuit. The DC/DC converter has a power electronic switch. The control circuit has a voltage detector detecting a DC output voltage of the DC/DC converter, a ripple voltage suppression circuit receiving the detected DC output voltage to generate an AC control signal for controlling an AC component of a duty ratio of the power electronic switch, an output voltage regulation circuit receiving the detected DC output voltage to generate a DC control signal for controlling an DC component of a duty ratio, an adder adding the AC and DC control signals to form a combined control signal, and a PWM circuit converting the combined control signal into a PWM signal to control the power electronic switch. Only the DC output voltage of the DC/DC converter has to be detected for the control circuit.

Abstract: In one embodiment, an SMPS includes a rectifier for generating an input DC voltage from an input AC voltage. A switching transistor is coupled to a primary coil of a transformer for generating power which is transferred to a second side of the transformer according to an operation of the switching transistor. A switching controller receives a feedback voltage corresponding to an output voltage, a sensing signal corresponding to a current flowing through the switching transistor, and a first signal corresponding to a voltage difference between a first electrode and a second electrode of the switching transistor. The switching controller controls an on/off operation of the switching transistor. The switching controller sets a threshold period whenever the first signal has a value greater than a reference value, thereby setting a plurality of threshold periods during operation of the switching mode power supply.

Abstract: The present invention relates to a senseless MPPT control apparatus of a photovoltaic power generation system and a method thereof. The control apparatus includes a current transformer, an A/D converter, a new and old current detector, a new duty ratio detector, an old duty ratio detector, a new and old duty ratio comparator, first and second new and old current comparators, a duty ratio adder, a duty ratio subtractor and a PWM signal generator. A maximum output point of a solar battery cell is tracked by using only one feedback current flowing into a load. Further, feedback factors can be reduced to one. It is possible to simplify the construction of a control circuit and minimize tracking control failure.

Abstract: A switching power supply includes an energy-storing device, a power switch, a driving circuit and a thermal sensing device. The energy-storing device is coupled to an input power source and controlled by the power switch to increase or decrease the power therein. The power switch has a control terminal connected to the driving circuit for switching. The thermal sensing device is connected to the control terminal of the power switch and powered by the driving circuit. When sensing an operation temperature exceeding a predetermined range, the thermal sensing device disables the driving circuit.

Abstract: A regulation circuit for use in DC to DC converter is disclosed. One such regulation circuit includes a feedback circuit to be coupled an energy transfer element output to receive a feedback signal to indicate whether the energy transfer element output is above or below a threshold level. A control circuit is included that is to be coupled to a switch that is coupled to an energy transfer element input. The control circuit is further coupled to the feedback circuit to generate a drive signal to control the switch to regulate the energy transfer element output to approximately the threshold level. The control circuit is to maintain an on-time of a current cycle of the drive signal and not allow an on-time of a next cycle of the drive signal in response to the energy transfer element output rising above the threshold level.

Abstract: A system and a method that uses primary side sensing to regulate the output voltage at a cable end without any remote sensing of cable connections back from the load. This is accomplished by approximating the current from the control voltage in the control loop through the relationship that defines the Ton time in terms of the control voltage Vc. Once the approximation of the output current is known, it is multiplied by a known fixed cable resistance, and this value is subtracted from the feedback sensor output before it is subtracted from the digital reference. This forces the regulator to raise the output voltage by the amount of drop across the cable, causing the output of the cable to be maintained at the targeted regulation point.

Abstract: A method and apparatus for converting DC electricity to AC electricity, the AC electricity having a sine wave shape. DC electricity is supplied to a pulse width modulator. A pulse width modulated signal is formed from the DC electricity, the pulse width modulated signal comprising a plurality of pulses, each pulse having a duration representing an amplitude of the sine wave during an interval of the sine wave represented by the pulse, the pulse width modulated signal comprising a plurality of pulses (or a pulse train) during one sine wave period. The sine wave is generated from the pulse width modulated signal, values of the sine wave during successive sine wave intervals responsive to the duration of the pulse that represents the sine wave interval.

Abstract: A controller for use in a power supply regulator is disclosed. One controller includes a feedback circuit coupled to generate a feedback current signal that corresponds to a peak switching current in response to a sense signal from a power supply regulator output. A comparator is coupled to compare the feedback current signal with a reference voltage. A modulation circuit is coupled to the feedback circuit to generate a pulse width modulated switching signal with fixed switching frequency in response to the feedback current signal and the reference voltage. A multi-cycle modulator circuit is coupled to the output of the comparator. The multi-cycle modulator circuit is coupled to enable or disable a switch signal from the controller to be coupled to a switch of the power supply regulator. A group of two or more consecutive switching cycles is separated from a next group having two or more switching cycles by a time of no switching.

Abstract: Methods and apparatus to provide low harmonic distortion AC power for distribution by converting energy from natural or renewable sources into electrical form, and constructing a current waveform on a primary winding of a transformer by recapturing inductive energy previously stored in the transformer so as to transform the converted electrical energy into substantially sinusoidal AC voltage at a secondary winding of the transformer. For example, AC power may be supplied to a utility power grid from raw electrical energy from renewable energy sources (e.g., solar cells). An inverter may construct the primary winding current waveform using two unidirectional switches. On each half cycle, one of the switches first applies energy previously recaptured from primary winding inductance, and then applies the raw energy to the transformer primary winding at the utility power grid frequency. Accordingly, the constructed primary winding current may exhibit substantially improved total harmonic distortion.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: An integrated control circuit for controlling a switching power supply, a switching power supply incorporating the same, and a method of controlling the switching power supply, where the control IC includes a current comparator that detects current flowing through a switching device, a flip-flop circuit that controls the ON-period of the switching device, an averaging circuit that converts the peak load current value to a time-average, a comparator that detects an overloaded state from the load current, a delay circuit that sets a time from detecting the overcurrent state to stopping the switching operation, a latch circuit that stops the switching operation for a period of time, a first reference voltage supply used in the current comparator, which has a higher voltage value than a second reference voltage supply used in the comparator.

Abstract: A multiple output switching power source apparatus includes first and second switching elements Q1 and Q2, a first series resonant circuit connected in parallel with Q1 or Q2 and having a first current resonant capacitor and a primary winding of a transformer that are connected in series, a first rectifying-smoothing circuit to rectify and smooth a voltage generated by a secondary winding of the transformer, a second series resonant circuit connected in parallel with the secondary winding and having a second current resonant capacitor and a second resonant reactor that are connected in series, a second rectifying-smoothing circuit to rectify and smooth a voltage of the second series resonant circuit, and a control circuit to determine an ON period of Q1 according to a voltage obtained from one of the first and second rectifying-smoothing circuits, determine an ON period of Q2 according to a voltage obtained from the other of the first and second rectifying-smoothing circuits, and alternately turn on/off Q1 an

Abstract: A controller is adapted for controlling a switch of a resonant direct current/direct current converter, and includes: a pulse width modulation controlling unit for detecting an output voltage of the resonant direct current/direct current converter, and for generating a pulse width modulation signal according to the output voltage detected thereby; a fixed frequency signal generating unit for generating a fixed frequency signal; and a logic synthesizing unit for synthesizing the pulse width modulation signal and the fixed frequency signal so as to generate a driving signal that is adapted to drive the switch of the resonant direct current/direct current converter.

Abstract: Single-phase full bridge boost converter systems and methods are provided. One system includes a direct-quatrature (D-Q) control system configured to generate a control voltage (vcon) including direct-phase and quadrature-phase voltage components. The system also includes a comparator configured to compare vcon to a carrier waveform voltage, generate switching commands based on the comparison, and transmit the switching commands to a current switch. Another system includes a boost converter including multiple switches coupled to a load and an AC voltage source. The switches are configured to provide charging current to the load in response to receiving switching commands. A D-Q control system configured to receive and delay an ia value, and issue switching commands based on the ia and delayed ia value is also included.

Abstract: A bi-directional DC-DC converter uses a transformer for both step-down and step-up operations. A switching frequency for operating a switching device is set separately for the step-down and step-up operations. When, for example, the switching frequency during the step-up operation is lower than the switching frequency during the step-down operation, the range in which the duty ratio in PWM control can be controlled is widened, compensating for step-up ratio insufficiency. Conversely, step-down ratio insufficiency is compensated for by making the switching frequency during the step-down operation lower than the switching frequency during the step-up operation.

Abstract: A power source device includes an input terminal, a first switching element connected to the input terminal, a second switching element connected to the first switching element, a transformer having a primary coil connected to a connecting node between the first and second switching elements, a low-pass filter including a series body of a coil and a capacitor connected to a secondary coil of the transformer, an output terminal connected to a connecting node between the coil and the capacitor, a comparator having a first input terminal connected to the output terminal, and an alternating signal generator connected to a second terminal of the comparator. An output terminal of the comparator is connected to each control terminal of the first switching element and the second switching element via the temporary amplitude generation permissible section.

Abstract: According to one aspect of the invention, a DC-DC converter including a soft-start function of a soft start in response to a soft-start signal, comprises: a detection circuit that detects whether the soft-start signal is active at an end of a soft-start operation; and an output voltage control circuit that controls an output voltage based on detection result of the detection circuit.

Abstract: A voltage detection device that is connected to a DC circuit to which a DC voltage is applied and that detects the DC voltage applied to the DC circuit includes a voltage conversion unit for outputting a first voltage that increases as the DC voltage increases and a second voltage that decreases as the DC voltage increases, an error detection unit for detecting an error for the first voltage and the second voltage based upon the first voltage and the second voltage when the DC voltage is 0, and a voltage calculation unit for correcting a difference between the first voltage and the second voltage based upon the error detected by the error detection unit and calculating the DC voltage based upon the corrected difference between the first voltage and the second voltage.

Abstract: In a PFC (Power Factor Correction) converter control unit, a PWM (pulse width modulated) signal is produced by comparing a PFC converter output voltage error signal, produced by a transconductance amplifier, with a ramp signal, which may be from a control unit of a resonant mode converter in cascade with the PFC converter. Level shifting is used to match the amplitude ranges of the compared signals. A current, representing an input current of the PFC converter and produced by a current mirror, is switched by the PWM signal to a parallel resistance and capacitance to produce a smoothed voltage constituting a control signal for the PFC converter.

Abstract: A method and apparatus is featured for providing linear control of a regulated electrical property (e.g., current or voltage) in a switch mode power supply of a thermal processing system that includes an inductive element and at least one switching element. The method and apparatus feature structure, or steps, for generating a nonlinear model that predict values for a regulated electrical property of the inductive element based on a given duty cycle of the at least one switching element and structure, or steps, for generating a nonlinear model that determines a duty cycle for the at least one switching element based on the nonlinear predictive model for the regulated electrical property, the nonlinear model determining the duty cycle such that a linear relationship results between the regulated electrical property and a selected value.

Abstract: A signal converter for generating switch drive signals for a multi-level converter comprises an input for a first pulse-width-modulation signal and a second pulse-width-modulation signal and an input for a polarity signal indicating a first polarity or a second polarity. The signal converter comprises four outputs for four switch drive signals for driving four switches of the multi-level converter. Also, the signal converter comprises a logic circuit for driving the switch drive signals in dependence on the polarity signal. The logic is configured to drive the switch drive signals in dependence on the polarity signal.

Abstract: A switched mode converter is disclosed that includes mode logic for switching between voltage mode and current mode. The converter includes sensing circuitry for sensing current on the primary side, load current on the secondary side, and converter output voltage. When load current is less than a predetermined value, the converter operates in voltage mode wherein output voltage of the voltage mode controller is used to control the duty cycle of a PWM controller. When load current is greater than a predetermined value, the converter operates in current mode wherein primary current is used to control the PWM controller. Thus during a light load when the converter is voltage controlled there is no need for a minimum load to stabilize the control loop. In current-mode the control loop will have faster transient response and avoid flux imbalance. Thereby providing advantages of both voltage and current controlled switched mode converters.

Abstract: A current-mode controller comprises an inductance element, at least one semiconductor switch coupled to the inductance element, and a ramp compensator coupled to sense an indication of current through the inductance element and coupled to control the at least one semiconductor switch that senses current during on-time of the DC-DC converter, infers current during off-time of the DC-DC converter, and determines a slope compensation signal based on the sensed and inferred currents.

Abstract: A sleep circuit for use in a resonant inverter is disclosed. The sleep circuit activates a “sleep mode” (non-continuous operation) when the inverter output has no connected load, or a connected load is non-operative (e.g., fails). The “sleep mode” utilizes hysteresis control via the under voltage lockout protection feature of a control IC of the inverter. A primary DC source permanently connects to the Vcc pin of the control IC for startup (on) and burst (non-continuous) operation modes. An auxiliary DC source connects to the Vcc pin via a switch for continuous operation mode. A load current sensor controls the switch. When a sensed output current is above a threshold level, the switch connects the auxiliary DC source, and the control IC (and the inverter) operates continuously. When the sensed output current falls below the threshold, the auxiliary DC source is not provided and the inverter operates in “sleep mode”.

Abstract: A switching power supply circuit uses a magnetic material that is harder to be magnetically saturated than ferrite as a core of a transformer or a choke coil and suitably protects a switching element. The circuit includes a transformer having a core made of a magnetic material of amorphous metal, a primary-side winding and a secondary-side winding. The circuit further includes a switching element for flowing current through the primary-side winding of the transformer according to a pulsive drive signal, and a primary-side current detection circuit for detecting the current flowing through the primary-side winding. The circuit further includes plural circuit elements for rectifying and smoothing a voltage generated in the secondary-side winding of the transformer to generate an output voltage, and a control circuit for generating the drive signal based on at least a detection result of the primary-side current detection circuit, and limiting a period for flowing the current in the primary-side winding.

Abstract: The present invention provides a method and a control circuit to detect an input voltage for the control and protections of a power converter. It includes a current sense circuit for generating a current signal in response to a switching current of a transformer. A detection circuit is coupled to sense the current signal for generating a slope signal in response to a slope of the current signal. A protection circuit is further developed to control the switching signal in accordance with the slope signal. The level of the slope signal is corrected correlated to the input voltage of the power converter.