Abstract: A light source control device is provided. A switching seat includes a switching key and a sensing device. A switching circuit is disposed between an external power source and a control circuit to disconnect or connect the external power source, and includes a mechanical switch, an electronic switch and a sensing unit. The mechanical switch is directly connected to the switching key, and is controlled to turn on or off by switching the switching key. The electronic switch is coupled to the sensing unit, and the sensing unit generates a sensing signal to control the electronic switch to turn on or off when the sensing device senses an excitation. The control circuit provides varied power supply to a light source according to the received signal.

Abstract: A driving device of an electric discharge lamp includes: a discharge lamp lighting unit which supplies power to the electric discharge lamp while alternately switching polarity of voltage applied between two electrodes of the electric discharge lamp to lighting the electric discharge lamp; and an anode duty ratio modulating unit which sets at least a first retention period and a second retention period having an anode duty ratio different from that of the first retention period and provided after the first retention period to modulate the anode duty ratios, assuming that each of the retention periods is a period for retaining an anode duty ratio as ratio of an anode period in which one of the electrodes operates as anode at a constant value in one cycle of the polarity switching, wherein the anode duty ratio modulating unit has a first modulation mode for operating the electric discharge lamp in steady condition and a second modulation mode for providing larger change of the anode duty ratio between the first

Abstract: Provided is a power branching system for driving a plurality of motors by use of a single servo driver, the power branching system capable of protecting each of the motors. The power branching system of the present invention has power lines 15 branched at some midpoint to connect the plural motors 5 and the servo driver 12; a plurality of current sensors 21 provided at branched power lines 15b for detecting currents supplied to the respective motors 5; and controlling means 22 for receiving current data detected by the plural current sensors 21, determining whether or not the detected currents are balanced and generating an alarm signal when the currents are unbalanced.

Abstract: A control and power device for a rotating electrical machine comprising a management circuit and a power circuit including a number of power transistors and driver circuits associated with the power transistors. The device provides connection between the management circuit and the driver circuits for switching on the driver circuits and transmitting at least one transit potential between the management circuit and the driver circuits. The invention is applicable to alternator-starter.

Abstract: A method of controlling an operation of an induction actuated container cover includes the steps of (a) normally retaining a cover panel of the container cover in a closed position; (b) detecting a target movement of a user by a sensor; (c) generating a first actuating signal to an actuation unit when the sensor detects the target movement of the user; (d) generating an actuation output from the actuation unit to the cover panel of the container cover, wherein the actuation output contains a decelerating and torque enhancing force which moves the cover panel of the container cover at an opened position; (e) pivotally actuating the cover panel of the container cover at the opened position via the actuation output to expose a storage cavity, and (f) generating a second actuating signal to pivotally actuate the cover panel of the container cover back to the closed position.

Abstract: A motor control device includes a magnetization control unit energizing a motor winding to change magnetic flux content of permanent magnet motor, a current detector detecting current supplied to the motor, a vector control unit including a speed/position estimation unit carrying out an operation to estimate a motor rotational speed and rotational position, the vector control unit carrying out a vector control of the motor, an induced voltage detector detecting an induced voltage of the motor based on the rotational speed, motor currents obtained by the vector control unit, output voltages of the drive unit, a winding inductance or the motor constant and a winding resistance, an induced voltage command determining unit determining an induced voltage command based on the motor rotational speed and output torque, and a magnetization current determining unit determining an amount of energization based on the induced voltage of the motor and the induced voltage command.

Abstract: In a driving apparatus for a three-phase synchronous motor, in which a battery is connected between a neutral point of a stator coil and a negative-pole bus, a control circuit acquires three-phase AC currents. The control circuit checks whether a neutral-point electric current is contained in an electric current detected by an electric current detecting section. Based on the check result, the control circuit checks whether electric current values for three-phases containing the neutral-point electric current are set together or electric current values for three-phases excluding the neutral-point electric current are set together to acquire the three-phase AC currents for driving the motor.

Abstract: A voltage detection section and current detection section detect a voltage and current supplied to a motor, and the detected voltage and current are supplied to a position detection section. An angular speed output from the position detection section is supplied to a differentiator to output an angular acceleration. A fundamental wave component extraction section extracts a fundamental wave component of the angular acceleration, and the extracted fundamental wave component is supplied to an amplitude adjustment section. The output of the amplitude adjustment section is subtracted from the average current command by a subtraction section. This subtraction result, current detection value, and the rotor position from the position detection section are supplied to a current control section to carry out the current control operation so as to obtain a current command.

Abstract: A motor driver that supplies a drive current to a stepping motor includes a decay rate controller configured to mix a first decay rate and a second decay rate smaller than the first decay rate with each other, and set a plurality of mix decay rates, a control logic circuit configured to create magnetization patterns for attenuating the drive current at the mix decay rates, and a drive current output circuit configured to output the drive current to the stepping motor in accordance with the magnetization patterns.

Abstract: A motor control device includes: a motor-current detection unit; a rotational-angular-speed calculation unit for calculating a rotational angular speed of a motor; a rotational-angle-change-amount calculation unit for multiplying the rotational angular speed by a predetermined time so as to calculate a motor-rotational-angle change amount within a predetermined time; a basic-drive-value calculation unit for calculating a basic drive value for driving the motor; a correction-value calculation unit for calculating a correction value for correcting the basic drive value based on the motor current and the motor-rotational-angle change amount; a correction unit for evaluating the motor drive value by correcting the basic drive value by the correction value; and a drive unit for driving the motor by using the motor drive value evaluated by the correction unit.

Abstract: An open-loop and/or closed-loop control device for operating an asynchronous machine which is fed by a 3-phase power converter. The open-loop and/or closed-loop control structure has a stator flux controller and a pulse pattern generator for generating pulse signals based on mean values. An output of the stator flux controller is connected to an input of the pulse pattern generator, with the result that the pulse pattern generator can generate the pulse signals as a function of a manipulated variable which is generated by the stator flux controller. The stator flux controller is configured so as to generate the manipulated variable as a function of a desired value of the stator flux of the asynchronous machine and as a function of a desired value of the torque of the asynchronous machine. The stator flux controller has a dead-beat control response.

Abstract: A driving device for driving a load and including a secondary cell, a fuel cell, and an energy management module. The energy management module is coupled to the secondary cell and the fuel cell and generates a first current or a second current to the load according to the voltage of the fuel cell.

Abstract: The present invention discloses a multi power supply system for a portable device, particularly a power supply system having a multi power input interface and a universal serial bus (USB) power output interface and capable of receiving a solar electric power and a general battery power. The invention not only provides a multiple of power transmission interfaces of a rechargeable battery of an electric backup power source for supplying power to the portable device, but also achieves the rectification and protection effects.

Abstract: An approach is provided that determines whether keyboard power connection points included in a wireless keyboard are connected to system power connection points in a computer system. Power is sent from the computer system to the wireless keyboard. The power is transmitted through the system power connection points to the keyboard power connection points. Keyboard components included in the wireless keyboard are also powered using the power sent from the computer system. If the keyboard power connection points are not connected to the system power connection points, the keyboard components are powered included in the wireless keyboard by using a keyboard battery that is included in the wireless keyboard. One of the keyboard components that receives power is a wireless interface that connects the wireless keyboard to the computer system.

Abstract: A vehicle control system has a battery mounted to a vehicle, a vehicle alternator charging the battery, a battery current detection device detecting a charging/discharging current of the battery, a voltage regulation device regulating an output voltage of the vehicle alternator to a specified output voltage, and a temperature sensor mounted to the inside of the battery current detection device. One terminal of a shunt resistance is connected to a negative terminal of the battery through a battery clump, and the other terminal of the shunt resistance is grounded. The temperature sensor is placed close to the shunt resistance. This structure enables the temperature sensor to detect the temperature of the battery with a high accuracy while considering the temperature characteristics of the shunt resistance.

Abstract: A multi-voltage power supply includes a transformer connecting to an AC power source to regulate voltage and deliver voltage-transformed electric power, a rectification output circuit connecting to the transformer to rectify the voltage-transformed electric power and output first DC power, and at least one voltage regulation circuit to receive the first DC power from a first DC power output line and regulate to become second DC power. The first DC power on the first DC power output line reaches a first potential after a voltage boosting period. The rectification output circuit has a rear end installing a hysteresis unit which adds a delay time in the voltage boosting period to defer the time of the first DC power reaching the first potential. Thereby the time difference between delivering DC power output of the first DC power and the second DC power can be regulated to avoid abnormal start of computers.

Abstract: A system, method and apparatus for contact-less charging of battery operated devices is presented. There is a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC. The method obviates the need for a voltage controller in each of both the host and the portable stages, thus decreasing complexity and increasing efficiency. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. Two embodiments for the charging circuitry in the portable device are presented. In one embodiment component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment charging efficiency is maximized regardless of the output voltage of the battery, but additional components are utilized.

Abstract: An induction charger for charging an electronic device includes a carrying car, a transmission assembly, a permanent magnet, an alternating current power supply, and an induction coil. The carrying car includes a base defined at least four slots scatted therein, a cover defining a through hole, at least two rotatable shaft, and at least two pairs of wheels positioned on a corresponding rotatable shaft and received in and passed through one corresponding slot. The transmission assembly includes a gear case defining a first through hole and a second through hole, a first hollow shaft non-rotatably fixed to the permanent magnet, and a second hollow shaft being inserted into a corresponding rotatable shaft. The induction coil is positioned in the base and aligned with and substantially parallel to the permanent magnet, and is electrically connected to the alternating current power supply.

Abstract: A control device for a secondary battery includes an offset addition unit calculating an offset amount based on a plurality of voltage values sensed by a sensor, the number of a plurality of battery cells included in one battery block and a preset range, and adding an offset amount to the sensed voltage values, when a flag is turned on to indicate the fact the voltage value of one of the battery cells falls within a preset range, and also includes an I/O control unit controlling charge/discharge of the battery based on voltage values containing the offset amount added thereto. Even when the battery voltage is sensed a battery block at a time, the voltage value can be controlled a cell at a time.

Abstract: A system and method for charging an undercharged cell of a bank of series connected cells utilizes a charging circuit. The charging circuit includes an inductor that receives current from the entire bank of cells and then provides current to the undercharged cell. Pulse width modulation is utilized to turn the switches on and off to regulate the current that flows to the inductor and thus is provided to the undercharged cell.

Abstract: Methods and systems are disclosed for utilizing a memory control circuit for controlling transfer of data to and from a memory system. A memory control circuit with a back up battery and control circuits is provided. Battery health is determined through a discharge cycle of the back up battery. A power supply generated from the back up battery is provided to circuitry of the memory control card during normal operations of the memory control circuit during a non-power loss state. The power supplied from the back up battery during the non-power loss state of the memory control circuit is utilized by at least a first circuit of the memory control circuit as part of normal memory controller card operations during the battery health discharge cycle. When the system is not performing a battery health cycle the first circuit receives normal system power. The memory control circuit may be a RAID card. The first circuit may be memory circuitry.

Abstract: Methods and systems are disclosed for utilizing a memory control circuit for controlling transfer of data to and from a memory system. A memory control circuit with a back up battery and control circuits is provided. Battery health is determined through a discharge cycle of the back up battery. A power supply generated from the back up battery is provided to circuitry of the memory control card during normal operations of the memory control circuit during a non-power loss state. The power supplied from the back up battery during the non-power loss state of the memory control circuit is utilized by at least a first circuit of the memory control circuit as part of normal memory controller card operations during the battery health discharge cycle. When the system is not performing a battery health cycle the first circuit receives normal system power. The memory control circuit may be a RAID card. The first circuit may be memory circuitry.

Abstract: This invention discloses a charging/discharging protective circuit for a secondary battery pack, having an over-charging/discharging voltage comparator, a reference voltage source and a battery status decision circuit. There is also a sampling circuit having a sequential pulse generator for generating pulses for selecting one of the batteries in the battery pack for testing purposes. The pulse generator provides M-channel gating pulses to the selection circuit of the battery under test and provides sampling pulses to the over-charging/discharging voltage comparators. The reference voltage source has a regulated output circuit. This invention uses time division inspection methods to provide a cost-effective solution for inspecting batteries in a battery pack.

Abstract: A device may include a battery and a plurality of components receiving power from the battery. A voltage of the battery is maintained above a threshold voltage by decreasing a current drawn by one of the components when the battery voltage approaches the threshold voltage.

Abstract: The application concerns a battery module, comprising cells, two external terminals, a message communication infrastructure, a module control unit comprising a message processing unit, connected to the infrastructure to send and receive messages. According to the application, at least two of the message systems chosen from among: a first message system for cell characterization, a second message system for cell forming, and a third message system for utilization of a battery pack comprising several modules connected via their user terminals, when the pack is associated with a consumer machine for the purpose of supplying it with electric energy, are provided in the message processing unit, which is able to be configured into any one of the message systems.

Abstract: A power charging assembly and methods are provided to provide a pre-charge low-current state, a steady-state, high-current charging state, and an unconnect state for an electrical load of an electrical propulsion system in a hybrid electrical vehicle (HEV). The power charging assembly includes a positive contactor device, a negative contactor device, and a non-contactor device means. The rate at which that electrical load is pre-charged may be effectively controlled by using a pulse-width modulated (PWM) signal received by the non-contactor device means. A current-only carrying positive or negative contactor may be configured with the non-contactor device means to further prevent electrical arcing of the contacts of the positive and the negative contactor during power charging assembly operation.

Abstract: This disclosure includes battery systems and operational methods. According to one aspect, a battery system includes conversion circuitry, a plurality of main terminals configured to be coupled with a load, a charger and a plurality of rechargeable battery modules which are coupled in series with one another intermediate the main terminals, switching circuitry configured to couple a first of the battery modules with an input of the conversion circuitry, and the conversion circuitry being configured to modify an electrical characteristic of electrical energy received from the first of the battery modules and to output the electrical energy having the modified characteristic to a second of the battery modules.

Abstract: A method and apparatus is disclosed to regulate an input voltage to provide a regulated output power. The regulated output power may include a smooth direct current (DC) component and an undesired alternating current (AC) component, the smooth DC component being an average of the regulated output power. A buck regulator module of the present invention regulates the smooth DC component to approximate a reference voltage. The buck regulator module additionally replicates the undesired AC component embedded within the regulated output power. A replicated undesired AC component is combined with the regulated output power to reduce the undesired AC component embedded within the output power.

Abstract: A battery charging and pulsating system including a battery having a positive terminal and a negative terminal, a charger electrically connected to the positive and the negative terminals of the battery, the charger including a controller, a pulsator electrically connected to the positive and the negative terminals of the battery, the pulsator including a controller, and a voltage measuring circuit electrically connected to the positive and the negative terminals of the battery, the voltage measuring circuit being adapted to measure a voltage across the positive and the negative terminals of the battery, wherein the controller of the pulsator is adapted to activate the pulsator when the measured voltage is at least one of (1) at or below a predetermined threshold voltage and (2) at or above a predetermined gassing voltage.

Abstract: A battery pack may include a plurality of battery cells; a discharge switch in series with the battery cells, a temperature sensor configured to sense temperature in the battery pack, and a battery control unit adapted to receive a signal indicative of temperature from the temperature sensor and operable to control the switch to interrupt current flow from the battery cells when the temperature exceeds an over-temperature threshold. The battery control unit may be adapted to receive a reset signal and operable to control the switch to restore current flow upon receipt of the reset signal and when the temperature is below an operating temperature threshold.

Abstract: A temperature sensing device can be embedded in a memory circuit in order to sense the temperature of the memory circuit. One oscillator generates a temperature variable signal that increases frequency as the temperature of the oscillator increases and decreases frequency when the temperature of the oscillator decreases. A temperature invariant oscillator generates a fixed width signal that is controlled by an oscillator read logic and indicates a temperature sense cycle. An n-bit counter is clocked by the temperature variable signal while the fixed width signal enables/inhibits the counter. The faster the counter counts, the larger the count value at the end of the sense cycle indicated by the fixed width signal. A larger count value indicates a warmer temperature. A smaller count value indicates a colder temperature.

Abstract: An alternator system includes a field circuit, a regulator that regulates a field circuit electrical flow through the field circuit, and an output current sensor that detects an actual current output from the alternator system. The alternator system further includes a controller that communicates with the regulator to vary the field circuit electrical flow based on the actual current detected by the output current sensor.

Abstract: A controller for reducing the harmonics contents in the AC-to-DC converter that is capable of minimizing THD due to crossover distortion. The controller can approximate the shape of the current running through boost inductor to the sinusoidal waveform of the rectified line input voltage and in the meantime to keep the valley of rectified sinusoidal waveform line voltage close to local ground value. The controller can be used in a transition mode power factor correction device suitable for a wide range of AC line input voltage and output loading application.

Abstract: In one embodiment, circuitry is provided for startup of a power converter. The circuitry includes a bias capacitor operable to be charged for providing energy to a controller of the power converter. A divider circuit is coupled to a voltage source. Current flows through the divider circuit. A switch, coupled to the divider circuit, is operable to be turned on and off to divert current flow in the divider circuit for charging the bias capacitor. This provides energy to the controller of the power converter at startup without employing an external bias source or high value bleeder resistor.

Abstract: A resonance type electric power conversion apparatus which includes a main circuit including a main reactor, a main switching device, an inverse-parallel diode and an output power diode, and an auxiliary circuit including an auxiliary reactor, an auxiliary switch, and an auxiliary capacitor connected in parallel to the main switching device for forming a recovery current elimination circuit and a partial resonance circuit for discharging charge accumulated in the auxiliary capacitor to turn on the inverse-parallel diode, includes recovery current elimination period calculation means for calculating a recovery current elimination period after the present point of time until the current flowing through the output power diode becomes zero and the charge of the output power diode disappears based on a voltage value across the auxiliary reactor, a current value of the main reactor and an inductance value of the auxiliary reactor, and control means for controlling the auxiliary switching device to turn on based on

Abstract: The present invention relates voltage conversion device in which a regulated output voltage is supplied by current pulses generated by the voltage conversion device from a voltage source. In particular, the invention relates to an improved control of an pulse frequency modulation (PFM) operation mode in which the frequency of the generated current pulses is modulated to regulated the desired output voltage, namely how PFM pulses can be generated without the need for a high-frequency clock of a time controlled system. By having pulse phases are current mode controlled and providing a mode detector to generate the right kind of current pulse, the high-frequency clock is no longer needed. Further, the presented solution allows for a higher PWM as well as PFM frequency, the external components of the converter can be made smaller. Eliminating the need for a high-frequency clock makes the device simpler, smaller and more energy-efficient.

Abstract: Apparatus and methods for reducing output load transients of a low dropout voltage regulator (“LDO”) are disclosed herein. A voltage regulator includes an output driver coupled to a regulator output pin, the output driver provides current to a load external to the regulator. A clamping device is coupled between the output pin and an internal node of the regulator. The clamping device forces a voltage at a control input of the output driver to follow the voltage at the output pin when the output driver is disabled.

Abstract: The invention relates to a DC to DC converter comprising a DC to DC converter unit (DCW), a first field effect transistor (FET1) for the voltage conversion, a bipolar transistor (BP1) as a starting aid, and a second field effect transistor (FET2) for switching-off the bipolar transistor (BP1). Said bipolar transistor (BP1) is mounted in parallel with the first field effect transistor (FET1), and the second field effect transistor (FET2) is mounted upstream of the bipolar transistor (BP1).

Abstract: A multi-phase power switching converter having first and second states includes a pulse width modulator having an output, a converter output providing an output signal, and a plurality of drivers, each having an output electrically coupled to the converter output and an input. When the converter is in the first state where a duty cycle of the converter is less than or equal to 100 divided by the number of drivers, each of the driver inputs is configured to be sequentially electrically coupled to the pulse width modulator output. When the converter is in the second state where the duty cycle of the converter is greater than 100 divided by the number of drivers, each of the driver inputs is simultaneously electrically coupled to the pulse width modulator output.

Abstract: A low dropout regulator includes an error amplifier, an N-type depletion MOSFET, a first switch, a second switch, a low-pass filter resistor, and a low-pass filter capacitor. By switching on both the first switch and the second switch, a voltage level of an output node at a negative input terminal of the error amplifier may be rapidly raised to be close to and lower than a voltage level of an input node at a gate of the N-type depletion MOSFET. Both the first switch and the second switch are then switched off immediately so that the voltage level of the output node is gradually raised to be equal to the voltage level of the input node through the low-pass filter resistor.

Abstract: A voltage regulator circuit and control method therefor. The circuit includes input and output terminals, an output transistor to pass a current from the input terminal to the output terminal according to a control signal, a reference voltage generator unit to generate and output a reference voltage, an output voltage detector unit to detect an output voltage output from the output terminal and generate and output a proportional voltage proportional to a detected voltage, a first error amplifier unit to control the output transistor to make the proportional voltage equal to the reference voltage, and a second error amplifier unit to respond to fluctuation in the output voltage faster than the first error amplifier unit and increase the output current from the output transistor for a period of time when the output voltage rapidly drops. Current consumption of the second error amplifier unit is changed according to the output current.

Abstract: A voltage regulator includes an amplifier and a regulation loop. The regulator includes a first PMOS transistor connected to a terminal supplying an input voltage, a second PMOS transistor connected in series with the first PMOS transistor. A node between those two transistors defines an output terminal. A first source of a first polarization current of fixed value is connected to the gate of the first transistor, and a second source of a second polarization current of fixed value connects the second transistor to ground. A third NMOS transistor is connected between the two current sources. A circuit is provided to modify automatically at least one of the polarization currents in relation to the load current.

Abstract: The present invention discloses an integrated circuit for system calibration, applicable to a power supply, comprising: a comparison module, having a feedback input end coupled to a feedback signal and a reference input end coupled to an analog reference signal for delivering a status signal; a detection and control module, for generating a reference signal and a calibration value according to the status signal, wherein the calibration value is derived from the reference signal at an instant when the status signal changes state, and the calibration value is stored into a calibration value register; a memory module, for receiving, storing and outputting the calibration value; and a reference signal generator, receiving the calibration value to provide the analog reference signal. The present invention can therefore be used to automatically calibrate a system with fewer external components to provide qualified systems.

Abstract: A voltage regulator includes a converter module, N comparators, and a decoder module. The converter module includes (N+1) resistors connected in series between a supply voltage and a common voltage, where N is an integer greater than 1. Each of the (N+1) resistors has a value that is different than values of others of the (N+1) resistors. The N comparators have first inputs connected to a reference voltage, and second inputs respectively connected to N nodes between the (N+1) resistors. The decoder module receives outputs of the N comparators and generates an R-bit output, where R is an integer greater than 1. Each bit of the R-bit output indicates a different one of R voltage ranges. A present value of the supply voltage lies in one of the R voltage ranges.

Abstract: A switching regulator that includes an inductor, a first step-down switch to store charge in the inductor, a second step-down switch to discharge the charge, a first step-up switch to store charge in the inductor, a second step-up switch to discharge the charge, a reverse current detector to detect a reverse current from an output terminal to the inductor through the second step-up switch, or an indication of the reverse current, based on a detection voltage, and a controller to control the first and second step-down switches, and the first and second step-up switches to output a predetermined constant voltage, and to shut off the second step-up switch to make shutdown condition when the detector detects the reverse current or an indication of the reverse current. The reverse current detector may have a threshold value in the step-down operation that is different from a threshold value in the step-up operation.

Abstract: In some embodiments, the number of active cells in a multi-cell voltage regulator is controlled so that the current-per-active-cell approaches a predefined target or to be within an acceptable range so that the active cells operate with suitable efficiency.

Abstract: A single integrator sensorless current mode control scheme for a switching power converter requires an amplifier circuit which produces an first current that varies with the difference Verror between a reference voltage and a voltage that varies proportionally with Vout, a circuit which produces a second current that varies with the voltage VL across the output inductor, a single integrating element connected to receive the first and second currents such that it integrates both Verror and VL, and a comparator which receives the integrated output at its first input and a substantially fixed voltage at its second input and produces an output that toggles when the voltage at its first input increases above and falls below the substantially fixed voltage. The comparator output is used to control the operation of the power converter's switching circuit and thereby regulate the output voltage.

Abstract: A wireless system includes a radio and a voltage regulator, which provides a supply voltage to the radio. The voltage regulator includes a storage element, at least one switch that is coupled to the storage element and a controller. The controller operates the voltage regulator in a continuous mode of operation, operates the voltage regulator in a discontinuous mode of operation in response to an output current of the voltage regulator decreasing below a predetermined threshold; operates the switch(es) to energize the storage element in response to a detection of whether an output voltage is below a threshold level; operates the switch(es) to halt the energization of the storage element in response to detecting a current in the storage element reaching a predetermined current threshold; operates the switch(es) to energize and de-energize the storage element in the discontinuous mode of operation; and operates the switch(es) to energize the storage element in synchronization with a periodic clock signal.

Abstract: A power system includes a switch, a capacitor and a comparator circuit. The power system receives a signal to turn off power supplied to the power system, turns off the switch that is used to supply power to the system and discharges the capacitor. The power system also compares a voltage across the discharging capacitor to a threshold voltage value, and turns on the switch to allow power to be supplied to the power system when the compared voltage across the discharging capacitor equals the threshold voltage value.

Abstract: There is provided a dead time control method capable of recognizing a critical situation in which a commutating transistor cannot be turned on because of a temporary variation in an output voltage of a synchronous rectifying DC-DC converter and adaptively preventing the commutating transistor from being turned on. The synchronous rectifying DC-DC converter compares an output Voff of an error amplifier with a voltage Vt obtained by multiplying the peak voltage of a ramp by G2. When Voff becomes greater than or equal to Vt, the converter determines that dead time is insufficient to control the switching of the commutating transistor and prevents the commutating transistor from being turned on.