Abstract: The present disclosure provides a smart connection device, a jump starter and a battery clamp. The smart connection device includes a power connection terminal coupled to an energy storage module, a load connection terminal coupled to an external load, a switch element, a power supply loop, and a reverse connection detection module. The reverse connection detection module outputs a first control signal to the power supply loop, when the external load is reversely coupled to the load connection terminal. The power supply loop is in a disconnection state and supplies no power to the switch element when it receives the first control signal. The switch element is in an off state when it receives no power supply, to make the power connection terminal and the load connection terminal be in a disconnection state, thereby preventing the energy storage module from providing a discharge output to the external load.

Abstract: An electronic device according to various embodiments may comprise a power converter configured to generate DC(direct current) power based on power obtained from outside, a state detecting unit, comprising a first photo coupler and a first diode electrically connected with the first photo coupler, configured to detect a state of a user device that comprises the electronic device or is electrically connected with the electronic device, a driving power supply unit configured to supply driving power for the user device based on the DC power, a power cut-off unit, comprising a first field effect transistor (FET), configured to cut off the DC power provided to the driving power supply unit according to the state of the user device, a control unit electrically connected with the state detecting unit.

Abstract: A measurement device configured to deliver a voltage corresponding to an overlay of an input voltage applied to the terminals of the measurement device and of an image voltage of a current circulating in a first capacitor to the terminals of which the input voltage is applied, the measurement device includes a shunt filter intended to be mounted in parallel with the first capacitor and comprising a second capacitor and a first resistor mounted in series with the second capacitor, a second resistor mounted in parallel with the second capacitor.

Abstract: A driver for improving reliability of a switch in a power device, comprising one or more sensors configured to sense an operational parameter of a power device. The driver comprises a controller configured to receive one or more sensor values from the respective sensors. The controller is configured to adjust a driving pulse according to the sensor values. The controller is configured to apply the driving pulse to one or more control terminal of one or more switch of the power device.

Abstract: A system for power management of an electronic device. The system comprises a programmable system microcontroller; power ports configured to sink or source electrical power; and a programmable power multiplexor connected between the power ports and the system microcontroller. The system further comprises bi-directional load switches connected between the power port and a bi-directional voltage convertor, and configurable to allow electrical power to flow through the bi-directional load switch. The bi-directional voltage convertor converts a first voltage supplied by the bi-directional load switch to a second voltage and supplies power at the second voltage to the electronic device or external device through the power ports. The programmable system microcontroller controls the direction in which each bi-directional load switch allows power to flow and the second voltage, such that the system sinks or sources power at each of the power ports according to programming of the system microcontroller.

Abstract: A circuit breaker includes a monitor to detect a performance of an electrical load in an electrical circuit, a converter to create a digital signal based on the detected performance of the electrical load, and a digital integrated circuit to compare the digital signal with a predetermined threshold reference signal, and generate a command signal to electrically disconnect the electrical load from the electrical circuit when a level of the digital signal exceeds the predetermined threshold reference signal. The electrical load may be configured to receive a fixed or variable amount of current or voltage. The predetermined threshold reference signal may include a signal level threshold and a time threshold. The digital integrated circuit may generate the command signal when the level of the digital signal exceeds the signal level threshold and the detected performance of the electrical load exceeds the time threshold.

Abstract: A power converter with over temperature protection compensation includes a main conversion unit, a primary-side control unit, a secondary-side control unit, a secondary detection circuit, and an over temperature adjustment circuit. The secondary-side control unit obtains a secondary voltage change value through the secondary detection circuit, and the secondary-side control unit correspondingly provides a current change value to the over temperature adjustment circuit according to the secondary voltage change value. The over temperature adjustment circuit provides a temperature control voltage according to the current change value so that the secondary-side control unit determines whether an over temperature protection is activated according to the temperature control voltage.

Abstract: A power converter with over temperature protection compensation includes a main conversion unit, a primary-side control unit, a primary detection circuit, and an over temperature adjustment circuit. The primary-side control unit obtains a primary voltage change value through the primary detection circuit, and the primary-side control unit correspondingly provides a current change value to the over temperature adjustment circuit according to the primary voltage change value. The over temperature adjustment circuit provides a temperature control voltage according to the current change value so that the primary-side control unit determines whether an over temperature protection is activated according to the temperature control voltage.

Abstract: A control device for a power semiconductor switch, has a first, second and third electrical control device terminal, and a control device that according to a control signal generates an actuation voltage on the third control device terminal and actuates the power semiconductor switch. An overcurrent detection circuit determines a first voltage corresponding to a primary power semiconductor switch voltage present between the first and second control device terminals and, if the first voltage, further to commence the generation of an actuation voltage for a switch-on of the power semiconductor switch, and if the voltage exceeds a reference voltage, to generate an overcurrent detection signal.

Abstract: There is provided a power supply device having a primary side on which a primary winding of a transformer is located and a secondary side on which a secondary winding of the transformer is located, and supplying power to a load, the device including: a photo coupler transmitting load short-circuit information from the secondary side to the primary side, a standby power supply terminal supplying power to the photo coupler; and a current passing unit connecting the photo coupler to the load.

Abstract: A power supply can provide brown-out protection and overheat protection. The power supply includes a rectifier, a transformer, and a power management device. The rectifier is used for receiving an alternating current voltage. The alternating current voltage has a voltage cycle. The transformer coupled to the rectifier has an inductor coupled to a switch for supplying an output voltage. The power management device is used for controlling the switch to make the inductor save power or release power. The power management device has a multi-functional pin coupled to the rectifier for receiving a detection voltage corresponding to a positive half cycle of the alternating current voltage. The multi-functional pin is also coupled to a thermistor for receiving an overheat protection signal.

Abstract: Systems and methods are provided for protecting a power conversion system. A system controller includes a first controller terminal and a second controller terminal. The first controller terminal is configured to provide a drive signal to close and open a switch to affect a first current flowing through a primary winding of a power conversion system. The second controller terminal is configured to receive first input signals during one or more first switching periods and receive second input signals during one or more second switching periods. The system controller is configured to determine whether a temperature associated with the power conversion system is larger than a predetermined temperature threshold, and in response to the temperature associated with the power conversion system being larger than the predetermined temperature threshold, generate the drive signal to cause the switch open and remain open to protect the power conversion system.

Abstract: A power supply apparatus supplies regulated power to an external apparatus. A power switch is turned on to receive AC power and turned off not to receive the AC power. The AC power is rectified by a rectifying section and is switched by a switching section into switched DC power which is smoothed by a rectifying/smoothing section. Upon reception of an alarm signal, the power disconnecting section stops sending the switched DC power to the rectifying/smoothing section. If the AC switch is turned off and then back on again after stopping sending the switched DC power to the smoothing section, the power disconnecting section allows receiving of the AC power only a time after turn-off of the power switch. Upon reception of an auto-off signal indicative of an idle state of the external apparatus, an auto-off section does not send the switched DC power to the rectifying/smoothing section.

Abstract: One embodiment of the invention relates to a switching control system for controlling an isolated power supply. The system includes a pulse-width modulation (PWM) switching controller configured to generate at least one primary switching signal having a first duty-cycle for activating at least one primary-side switch of the isolated power supply. A synchronous rectifier (SR) switching controller is configured to generate at least one SR switching signal having a second duty-cycle for activating at least one SR switch of the isolated power supply to conduct an output current through a secondary winding of a transformer and an output inductor to generate an output voltage, the second duty-cycle being independent of the first duty-cycle in a soft-start mode.

Abstract: An example controller for a power converter includes a feedback sampling circuit, drive logic and a false sampling prevention circuit. The feedback sampling circuit is coupled to sample a feedback signal received from a terminal of the controller and to generate a sample signal representative of a value of the feedback signal. The drive logic is coupled to the feedback sampling circuit and coupled to control the power switch to regulate an output of the power converter in response to the sample signal. The false sampling prevention circuit is coupled to receive a sampling complete signal that indicates when the sampling of the feedback signal is complete. The false sampling prevention circuit is further coupled to the drive logic to extend the off time of the power switch until the sampling complete signal indicates that the sampling of the feedback signal by the feedback sampling circuit is complete.

Abstract: An active clamp DC-DC converter includes a transformer having a primary coil and a secondary coil, a main switching device connected in series to the primary coil of the transformer so that the main switching device and the primary coil are connected in parallel to a DC power source, a reset capacitor, a reset switching device connected in series to the reset capacitor so that the reset switching device and the reset capacitor are connected in parallel to the primary coil of the transformer, a rectifying circuit connected to the secondary coil of the transformer, a smoothing circuit connected to the rectifying circuit, and a control circuit adjusting a dead time that elapses from the time when the reset switching device is turned off until the time when the main switching device is turned on, based on a voltage across the main switching device.

Abstract: A power converter includes a dc input having first and second terminals. A main converter is coupled to the first terminal of the dc input. A standby circuit coupled to the second terminal of the dc input and the main converter. The main converter is coupled to control a transfer of energy from the dc input through the standby circuit to a main output of the main converter during a normal operating condition of the power supply. The standby circuit is coupled to decouple the main converter from the second terminal of the dc input during a standby operating condition of the power converter. A standby converter is coupled to the first and second terminals of the dc input to control a transfer of energy from the dc input to a standby output of the standby converter during the standby operating condition of the power converter.

Abstract: A monitoring and control circuit comprises a sense block, a first and a second comparators, and a control module. The current sense block is coupled to a switch for generating a monitoring signal indicative of a current flowing through the switch. The first comparator coupled to the sense block is operable for comparing the monitoring signal to a first threshold and for providing a first signal according to a first comparison result between the monitoring signal and the first threshold. The second comparator coupled to the sense block is operable for comparing the monitoring signal to a second threshold and for providing a second signal according to a second comparison result between the monitoring signal and the second threshold. The control module coupled to the first comparator and the second comparator provides a control signal for controlling the switch according to the first signal and the second signal so as to adjust the current.

Abstract: System and method for regulating an output voltage of a power conversion system. The system includes an error amplifier coupled to a capacitor. The error amplifier is configured to receive a reference voltage, a first voltage, and an adjustment current and to generate a compensation voltage with the capacitor. The first voltage is associated with a feedback voltage. Additionally, the system includes a current generator configured to receive the compensation voltage and generate the adjustment current and a first current, and a signal generator configured to receive the first current and a second current. The signal generator is further configured to receive a sensing voltage and to generate a modulation signal. Moreover, the system includes the gate driver directly or indirectly coupled to the signal generator and configured to generate a drive signal based on at least information associated with the modulation signal.

Abstract: A power isolation system and method is disclosed. The system includes a transformer suitable for use in the power isolation system, and a semiconductor device electrically connected to the transformer to provide a reduction of the inrush current associated with powering the transformer, wherein the semiconductor device is activated upon power up based upon the previous shutdown state of the power isolation system to provide a soft start to the transformer, and after activation of the transformer, the semiconductor device is shorted in the system.

Abstract: A power converter with low power consumption during a standby operating condition. An example power controller includes a main converter coupled to a dc input of the power converter to control a transfer of energy from the dc input of the power converter to a main output of the power converter. A standby converter is also included and is coupled to the dc input of the power converter to control a transfer of energy from the dc input of the power converter to a standby output of the power converter during a standby operating condition of the power converter. A standby circuit is also included and is coupled to the dc input of the power converter and coupled to the main converter. The standby circuit decouples the main converter from the dc input of the power converter during the standby operating condition of the power converter.

Abstract: System and method for regulating an output voltage of a power conversion system. The system includes an error amplifier coupled to a capacitor. The error amplifier is configured to receive a reference voltage, a first voltage, and an adjustment current and to generate a compensation voltage with the capacitor. The first voltage is associated with a feedback voltage. Additionally, the system includes a current generator configured to receive the compensation voltage and generate the adjustment current and a first current, and a signal generator configured to receive the first current and a second current. The signal generator is further configured to receive a sensing voltage and to generate a modulation signal. Moreover, the system includes the gate driver directly or indirectly coupled to the signal generator and configured to generate a drive signal based on at least information associated with the modulation signal.

Abstract: A power supply circuit includes a direct current (DC) voltage source, a protecting circuit having a first switching element, a pulse width modulation (PWM) circuit having a first terminal, a switching circuit, and a transformer. The DC voltage source is configured to provide a first DC voltage. The first terminal is configured to receive the first DC voltage via the first switching element to enable the PWM circuit. The PWM circuit is configured to switch on or switch off the switching circuit. The transformer is configured to convert the first DC voltage to an alternating current (AC) voltage in cooperation with the switching circuit.

Abstract: A controller for a switching mode power supply includes two semiconductor chips. The first semiconductor chip has a high-voltage startup transistor coupled to a high voltage supply input terminal and configured to provide a charging current in a startup phase or protection mode of a switching mode power supply (SMPS) and to provide substantially no current in a normal operation phase of the SMPS. The second semiconductor chip has a control circuit for controlling the switching mode power supply. The second semiconductor chip also has first and second on-chip high-voltage resistors coupled to the high-voltage supply input terminal and the high-voltage startup transistor in the first semiconductor chip. The first and the second on-chip high-voltage resistors are configured to provide a voltage and a current related to a voltage at the high-voltage supply input terminal.

Abstract: The present invention provides a switching power supply device capable of automatically restarting an electrical apparatus without a user operation when a voltage of the electrical apparatus or an operation of the electrical apparatus is abnormal. The switching power supply device is provided with a short-circuiting switch for a shunt regulator included in the feedback circuit. When an abnormal condition occurs in a secondary side circuit, the short-circuiting switch is turned on by means of a control signal to reduce a voltage of a primary side auxiliary winding and temporarily stop an operation of a primary side control circuit and of a switching element. A primary side capacitor continues to be charged by a power supply through a starting resistor. The primary side control circuit and the switching element automatically restart to operate.

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: We describe a switching power converter comprising a bipolar switching device (BJT or IGBT) switching an inductive load, and including a closed-loop control system. The control system comprises a voltage sensing system to sense a voltage on a collector terminal of the switching device and provide a voltage sense signal; a controller; and a drive modulation system coupled to an output of the controller for modulating a drive to the control terminal of said bipolar switching device responsive to a controller control signal; wherein said controller is configured to monitor changes in the sensed voltage during a period when said switching device is switched on and to control said drive modulation system to control the degree of saturation of said bipolar switching device when the device is switched on and hence improve turn-off times.

Abstract: An AC-DC power converter controls an external upstream switching device, which supplies it power to be converted. Power conversion is initiated when an external signal requests power be converted or when a program within the AC-DC power converter detects the need for power conversion. When this occurs, the AC-DC power converter signals the external switching device, which is upstream of the AC-DC power converter to turn on, thereby supplying the power to be converted to the AC-DC power converter.

Abstract: A power converter and a PWM controller for compensating a maximum output power includes a power switch, an oscillator, a control circuit and a delay modulator. The oscillator generates a pulse signal. The control circuit is coupled to the oscillator for generating a PWM signal and an over current signal in response to the pulse signal and a current sense signal of the power converter. The delay modulator is coupled to the control circuit for generating a delay control signal in response to the PWM signal and the over current signal, wherein the delay control signal is used to prolong a propagation delay time of the control circuit in response to the on-time of the PWM signal, and the propagation delay time can be compensated by the on-time of the PWM signal to limit the maximum output power under a high-line input voltage and a heavy-load condition.

Abstract: Disclosed is an overload protection delay circuit for use in a switching power supply for enabling the switching power supply to detect overload problems with high accuracy. The overload protection delay circuit is connected between a photo coupler and a pulse-width modulator of the switching power supply, and is consisted of an energy storage device such as a capacitor and a charging controller such as a zener diode. The charging controller is configured to set a limit value for allowing the energy storage device to be charged by an internal current source of the pulse-width modulator when the feedback signal of the switching power supply reaches the limit value. By charging the energy storage device, a time delay is added to the feedback signal so that the pulse-width modulator can accurately activate the internal overload protection mechanism without the interference of load transients.

Abstract: Mitigating the DC content of an AC output from an inverter is important for electrical system reliability. The inverter may be powered by unbalanced DC inputs while still mitigating the DC content of the AC output wavefrom. The present invention provides methods to mitigate the DC content in the output DC voltage by reshaping the PWM reference signals (carrier signals) according to the DC content in such a way that the DC content is canceled. These reshaped PWM reference signals may be, for example, unsymmetrical reference waveforms. Unlike conventional methods for providing an AC voltage from a DC voltage with an inverter, which may result in DC content in the output AC voltage when an unbalanced DC input voltage is supplied, the present invention provides methods for mitigating the DC content in an AC voltage, even if the inverter providing the AC voltage is supplied with unbalanced DC voltage.

Abstract: A capacitor charging circuit is provided with a primary side output voltage sensing circuit including an RC network having an RC time constant with a predetermined relationship to the RC time constant of the output capacitor. Once the capacitor voltage reaches a fully charged level, the charging mode is terminated. The output voltage is continuously detected by measuring the voltage across the primary side RC network that decays at a predetermined rate with respect to the output capacitor and the charging mode is commenced once the RC voltage falls to a predetermined level. According to a further aspect of the invention, a switch control circuit in a flyback converter controls the switch off time in response to detection of a change in the slope polarity of the voltage at a terminal of the switch.

Abstract: We describe a resonant discontinuous power converter including a magnetic energy storage device, and a bipolar junction transistor (BJT) switch having a collector terminal coupled to repetitively switch power from the input on and off to said magnetic energy storage device such that power is transferred from the input to the output. During an off-period of said BJT switch a voltage on said magnetic energy storage device and on said collector terminal of said BJT is at least partially resonant. The power converter includes a voltage clamping circuit to clamp a base voltage on a base terminal of said BJT during a resonant portion of said off-period to limit an excursion of a collector voltage on said collector terminal of said BJT towards or beyond an emitter voltage of said BJT during said resonant portion of said off-period, in particular to inhibit reverse bias of a base emitter junction of the transistor.

Abstract: The switching power supply apparatus includes detection means for detecting that leak current of an input smoothing capacitor becomes a predetermined value or more and first auxiliary switching means connected in series with respect to the input smoothing capacitor. The first auxiliary switching means becomes an on state during a normal operation, whereas the first auxiliary switching means goes into an off state in a case where the detection means detects that the leak current of the input smoothing capacitor becomes a predetermined value or more.

Abstract: A switching mode power supply and a corresponding method of protection operation is presented. A switching controller of the switching mode power supply receives current sensing information corresponding to the current flowing through a main switch and feedback information corresponding to an output voltage through a single terminal, and performs a protection operation when the voltage at the terminal is maintained to be lower than a reference voltage for more than a predetermined time frame. The power supply requires a low number of terminals, while preserving the protection operation function.

Abstract: There are included an actuation unit supplying an actuation power to a control unit to start a switching operation of a switching element when an alternating-current power sources turned on, and stopping supply of the actuation power to the control unit after the switching operation of the switching element is started; an overheat detection unit being thermally coupled with the actuation unit and detecting an abnormal condition due to overheating of the actuation unit; a latch maintaining an inoperative state of the switching element at the event of an abnormal condition other than the abnormal condition due to overheating of the actuation unit; and an actuation controller configured to discharge an electrical charge of a smoothing capacitor while the latch maintains the inoperative state of the switching operation to speedily reset the latch unit when the alternating-current power source is turned off, and to stop the actuation unit in response to a detection signal from the overheat detection unit.

Abstract: We describe a switching power converter comprising a bipolar switching device (BJT or IGBT) switching an inductive load, and including a closed-loop control system. The control system comprises a voltage sensing system to sense a voltage on a collector terminal of the switching device and provide a voltage sense signal; a controller; and a drive modulation system coupled to an output of the controller for modulating a drive to the control terminal of said bipolar switching device responsive to a controller control signal; wherein said controller is configured to monitor changes in the sensed voltage during a period when said switching device is switched on and to control said drive modulation system to control the degree of saturation of said bipolar switching device when the device is switched on and hence improve turn-off times.

Abstract: The invention presents a switching power control circuit including two levels of under voltage lockout to improve the protection of the power supply. An input terminal of control circuit is connected to a supplied capacitor to supply the power of the control circuit. The supplied capacitor is charged through a start resistor for the start-up. Once the input voltage reaches a start-up voltage, the control circuit will start the operation. After that, the power is further supplied from a transformer of the power supply. If a fault condition is occurred, the switching of the control circuit will be stop and the supplied capacitor will be discharged. When the input voltage is discharged lower than a first under-voltage lockout threshold, the circuits of control circuit are shut down to consume lower power. Furthermore, once the input voltage is discharged lower than a second under-voltage lockout threshold, the control circuit will enable the start-up again.

Abstract: The present invention provides an overpower-protection circuit and a power supply apparatus having the same. The power supply apparatus comprises a rectifier, a transformer and an overpower-protection circuit. The overpower-protection circuit comprises a converter having a converter input electronically coupled to the rectifier and a converter output, a photo coupler having at least a first terminal coupled with the converter output, and having an output terminal, and a clipper electrically coupled across said terminals of the photo coupler for keeping the converter output below a predetermined voltage.

Abstract: An over-power protection apparatus with programmable over-current threshold for a power converter is provided. The over-power protection apparatus further provides an over-temperature threshold for protection purposes. The over-power protection apparatus is able to achieve over-power and over-temperature protection in response to the level of the driving signal of the power converter. In addition, the programmable over-current threshold of the present invention can be adjusted in response to various load conditions.

Abstract: A high-efficiency power supply apparatus used with a driving system of a display panel and a method of designing the same to improve an electrical power efficiency by providing a non-isolated direct current (DC) power directly to a display panel driving circuit comprise: a DC power supplying circuit to improve a power factor by rectifying an alternating current (AC) power and generating the non-isolated DC power, which is not isolated from the AC power, and an isolated DC power; a display panel driving circuit to generate various driving signals for driving the display panel with the non-isolated DC power; and a video signal processing circuit to perform a predetermined video signal processing for generating data to drive the display panel with the isolated DC power.

Abstract: A single-stage input-current-shaping (S2ICS) flyback converter achieves substantially reduced conduction losses in the primary side of the S2ICS flyback converter by connecting a bypass diode between the positive terminal of a full-bridge rectifier and the positive terminal of an energy-storage capacitor. An effective current interleaving between an energy-storage inductor and the bypass diode is thus obtained in the S2ICS flyback converter around the peak of the rectified line voltage, resulting in a significantly reduced input-current ripple and reduced current stress on the switch. Further, by rearranging the rectifiers in the ICS part of the S2ICS flyback converter in such a way that the energy-storage capacitor and the ICS inductor are connected to the ac line voltage through only two rectifiers, one diode forward-voltage drop is eliminated, which results in a substantially reduced conduction loss in the primary-side rectifiers.

Abstract: A surge voltage detection circuit compares a stipulated voltage VS with the drain voltage of a switching element, the drain voltage being applied by a smoothing capacitor. The comparison result is supplied to a switching control circuit. If the drain voltage of the switching element is higher than the stipulated voltage VS, the switching control circuit inhibits the operation of the switching element. As a result, no switching operation is started, and the drain voltage of the switching element does not exceed the breakdown voltage of the element.

Abstract: A protection circuit for a multiple output switching mode power converter protects against an over-current or short circuit failure condition. The protection circuit activates the soft-start circuit of the PWM control circuit upon detection of the over-current or short circuit condition. The soft-start circuit then shuts off operation of the power converter and restarts the power converter after a period of time defined by the soft-start circuit. The protection circuit is effective with any type of power converter topology (e.g., buck, boost, flyback, and forward converter), isolated or non-isolated, having dual or multiple outputs.

Abstract: A protection circuit for a multiple output switching mode power converter protects against an over-current or short circuit failure condition. The protection circuit activates the soft-start circuit of the PWM control circuit upon detection of the over-current or short circuit condition. The soft-start circuit then shuts off operation of the power converter and restarts the power converter after a period of time defined by the soft-start circuit. The protection circuit is effective with any type of power converter topology (e.g., buck, boost, flyback, and forward converter), isolated or non-isolated, having dual or multiple outputs.

Abstract: The present invention provides an integrated controller for use with a power supply employing a pulse width modulator and a method of operation thereof. In one embodiment, the integrated controller includes a primary control circuit configured to provide a control signal to the pulse width modulator. Additionally, the integrated controller includes a feedback circuit configured to monitor an output signal of the pulse width modulator and to modify the control signal thereby enabling a substantially monotonic increase in an output voltage of the power supply output voltage during a non-steady state period of operation thereof.

Abstract: An intermittent switching power supply circuit prevents excessive output power on a secondary side of a circuit. An intermittent oscillator is alternately switched on and off to maintain output voltage and/or current roughly constant. An output power monitoring circuit monitors output power from a rectifying/smoothing circuit. A control circuit outputs a stop control signal to an control terminal of the intermittent oscillator when the output power monitoring circuit determines that the output voltage and/or current exceeds a reference value. The protection circuit and a photocoupler receiver element are connected in parallel with the control circuit. Where a circuit error occurs and the photocoupler receiver element fails to cycle the intermittent oscillator between active and inactive conditions for a predetermined time, the protection circuit provides a backup which outputs a stop control signal to stop oscillation of the intermittent oscillator element.

Abstract: A restart circuit for a power supply of an electronic system such as a computer system for delaying the restart of the power supply until a power supply output is in compliance with a specified parameter. In one embodiment, the specified parameter is a particular threshold voltage level and the power supply output is in compliance when it is less than the particular threshold voltage level. In another embodiment of a restart circuit, the specified parameter is a rate of decay in a voltage level and the power supply output is in compliance when it is decaying at a rate less than the predetermined rate. In one embodiment, delaying the restart of the power supply permits components of the system to be reset when the voltage level of the power supply output is in a known state.

Abstract: A method to dynamically clamp the feedback control voltage in DC—DC converters, with the purpose to limit the duty-cycle and to protect the magnetic components against saturation, over a wide range of input voltage conditions. The clamping level is function of input voltage and allows the design optimization of the magnetic components in the way of minimizing their size and is active only during transient events, when momentary open loop condition may occur.

Abstract: A PWM current control circuit that determines whether a start-up time, during which an decreased current is being drawn, for a load has elapsed and providing a switch that supplies current to the load with a control signal that limits the current being drawn if the start-up time has not elapsed and providing a standard PWM control signal from a microcontroller if the start-up time has not elapsed. Excessive inrush current during the start-up period of the load is avoided while the current is maintained to be within a predetermined range during start-up and after the start-up time has elapsed the control is again turned over to the microcontroller.