Abstract: A current detector for an output load includes a high side power transistor; a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors to provide cycle by cycle control of the conduction of the high and low side power transistors, wherein if the controller detects zero or negative current in the output inductor, using a dead time between when the low side power transistor turns off and before the high side power transistor turns on, the low side power transistor is held off during the entirety of the next switching cycle.

Abstract: A circuit may generate a clock signal with a variable period given by a ratio between an initial switching period and a number of phase circuits through which a current of a multi-phase PWM voltage converter flows. The circuit may include an adjustable current generator driven by a signal representing the number of phase circuits through which the current flows and configured to generate a current proportional to the number of phase circuits through which the current flows, and a tank capacitor charged by the adjustable current generator. The circuit may include a comparator of a voltage on the tank capacitor with a threshold value configured to generate a pulse of the clock signal when the threshold value is attained, and a discharge path of the tank capacitor, the discharge path being enabled during the pulses of the clock signal.

Abstract: A high electrical field driver for producing high electrical field is invented based on the switching circuit. The inventive high electrical field driver can produce at least one high electrical field.

Abstract: Devices for reducing the open circuit voltages of solar systems are described. In one embodiment, a solar system includes a string of a plurality of solar modules having an open circuit voltage. The solar system also includes a device for reducing the open circuit voltage of the string of the plurality of solar modules during an open circuit configuration.

Abstract: A power conversion apparatus includes a converter having an input power source Vin, a reactor L1, a switching element Q1, and a rectifying element D1, a smoothing capacitor C1 connected to an output terminal of the converter, and a controller 10b to turn on/off the switching element and thereby control power to be outputted from the converter. The controller has a pulse generator 15 to generate a pulse signal according to an input voltage to the converter and an output voltage from the converter, the pulse signal being used to turn on/off the switching element. The controller also has an adjuster 18 to mask an ON time of the pulse signal for a predetermined time and thereby provide the pulse signal with an adjusted ON time, the adjusted ON time determining a duty ratio at which the switching element is turned on/off.

Abstract: A microprocessor operated controller device and associated method for modifying an AC input power to provide a reduced power AC output power to a load when coupled to the controller device. The AC output power has a series of cut-out pulses in each half cycle of the AC output power waveform. The device includes a switching system having a plurality of switching elements for positioning the series of cut-out pulses in each half cycle of a waveform of the AC input power to result in said reduced power AC output power and a switch control system for coordinating opening and closing of the plurality of switching elements during positioning of the series of cut-out pulses. The switch control system includes a synchronization system for synchronizing the switching system with timing of each half cycle of the AC input power waveform.

Abstract: A power source apparatus includes: a switch circuit to receive an input voltage; a control circuit to switch the switch circuit from a second state to a first state at a timing corresponding to a comparison result between a feedback voltage generated based on a first voltage corresponding to an output voltage and a reference voltage generated based on a standard voltage set in accordance with the output voltage; and a voltage generation circuit to add a compensation voltage generated by voltage-converting a time period in which the switch circuit switches from the second state to the first state to one of the first voltage and the standard voltage, to generate the feedback voltage, to add a slope voltage which changes at a slope to one of the first voltage and the standard voltage, and to generate the reference voltage.

Abstract: In order to achieve an object to reduce a surge voltage and suppress noise generation, the present invention provides a DC-DC converter with a snubber circuit, which boosts a voltage Vi of a DC power supply. The snubber circuit includes: a series circuit connected to both ends of a smoothing capacitor Co and including a snubber capacitor Cs and a snubber resistor Rs; a snubber diode Ds1 connected to a node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lr1 and an additional winding 1b of a transformer T1 are connected; and a snubber diode Ds2 connected to the node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lr2 and an additional winding 2b of a transformer T2 are connected.

Abstract: A shunt regulator for an RFID tag chip is powered from split outputs from the RF rectifier, including a first output for providing a power delivery path to on-chip circuits and a second output for providing a discharge-regulation path. The shunt regulator includes a capacitor coupled between the first output and ground. The shunt regulator further includes an input node for receiving a power supply voltage from the rectifier split outputs, a first diode having an anode coupled to the input node, a second diode having an anode coupled to the input node, a resistor divider circuit and amplifier coupled between a cathode of the first diode and ground, transistor having a control terminal coupled to an output of the resistor divider and amplifier circuit, and a current path coupled between a cathode of the second diode and ground.

Abstract: A novel voltage regulator includes an indictor, a switching transistor, a rectifier, an error amplifier circuit, a first voltage comparator circuit, a second voltage comparator circuit, an oscillator circuit, and a driver circuit. The first voltage comparator circuit outputs a modulation signal. The second voltage comparator circuit activates an enable signal when the error voltage exceeds the second reference voltage. The oscillator circuit outputs a clock signal with a fixed frequency according to the enable signal. The oscillator circuit enters a first state when the enable signal is activated and deactivated within a period of time shorter than a threshold time, and enters a second state when the enable signal remains activated during a period of time longer than the threshold time. The driver circuit generates the switching control signal based on the clock signal and the modulation signal.

Abstract: A synchronous boost DC/DC conversion system comprises an input for receiving a DC input voltage, an output for producing a DC output voltage, a power switch controllable to adjust an output signal of the conversion system, and an inductor coupled to the input. A synchronous rectifier is configurable to create a conduction path between the inductor and the output to provide the inductor discharge. A control circuit is provided for controlling the synchronous rectifier as the input voltage approaches the output voltage, so as to adjust average impedance of the conduction path over a discharge period of the inductor.

Abstract: A method of operating a switching power converter having at least one power switch controlled by a drive signal having a switching frequency is disclosed. The method includes monitoring an output power of the switching power converter, determining whether the output power has decreased below a threshold level and, in response to the output power decreasing below the threshold level, changing the switching frequency of the drive signal from a first switching frequency to a second switching frequency when an operating condition of the switching power converter is satisfied. Also disclosed are controllers and switching power converters (including PFC converters).

Abstract: The present invention relates to power supplies, and more particularly, to a power supply having a maximum power point tracking function that can reduce manufacturing costs and circuit size by using a maximum power point tracking section with a simplified circuit in a solar photovoltaic power generator supplying power using sunlight instead of using a micro controller, the maximum power point tracking section that controls power switching according to a result of integration of a value obtained by dividing a power variation by a voltage variation to track a maximum power value.

Abstract: Power converters and associated methods of operation are disclosed herein. In one embodiment, a power converter includes a first switch and a second switch electrically coupled to the first switch in series. The first switch is electrically coupled to a first node and to a second node via the second switch. The power converter further includes a capacitor and a third switch electrically coupled to the first node and to the second node via the capacitor and the second switch. The third switch has a linear-active region of operation.

Abstract: A circuit for recovering charge at the gate of an output transistor arranged to drive the output of a switching circuit such as a switching regulator or controller. A substantial portion of the charge for each switching cycle is recovered under a wide range of load conditions for the switching circuit, e.g., no load, partial load, or full load. Also, charge recovery operates effectively with a switching circuit that is arranged to switch in a synchronous or asynchronous manner. Additionally, if the output voltage of a switching circuit is 12 or more volts, the amount of charge that can be saved can be relatively substantial.

Abstract: A DC/DC converter including an inductor and a capacitor is started by connecting an input voltage to the inductor and shunting a current around the inductor so as to pre-charge the capacitor to a predetermined voltage.

Abstract: Embodiments for at methods, apparatus and systems for operating a voltage regulator are disclosed. One method includes generating, by a switching controller, a switching voltage through controlled closing and opening of a series switch element and a shunt switch element. Further, the method includes generating, by a switchable output filter, a regulated output voltage by filtering the switching voltage, wherein the switchable output filter comprises a plurality of capacitors that are selectively included within the switchable output filter.

Abstract: DC-DC converters are described that employ a time-averaged modulated bypass diode to facilitate the efficient harvest of power in photovoltaic systems.

Abstract: A buck regulator comprises an upper switching transistor connected between a voltage input node and a phase node. A lower switching transistor is connected between the phase node and a ground node. An inductor is connected between the phase node and an output voltage node. Circuitry generates control signals to the upper switching transistor and the lower switching transistor responsive to the output voltage and a reference voltage. The control signals to the lower switching transistor selectively turn off the lower switching transistor responsive to a current direction through the lower switching transistor and an indication of whether a voltage error signal has been clamped at a selected level.

Abstract: A circuit may generate a clock signal with a variable period given by a ratio between an initial switching period and a number of phase circuits through which a current of a multi-phase PWM voltage converter flows. The circuit may include an adjustable current generator driven by a signal representing the number of phase circuits through which the current flows and configured to generate a current proportional to the number of phase circuits through which the current flows, and a tank capacitor charged by the adjustable current generator. The circuit may include a comparator of a voltage on the tank capacitor with a threshold value configured to generate a pulse of the clock signal when the threshold value is attained, and a discharge path of the tank capacitor, the discharge path being enabled during the pulses of the clock signal.

Abstract: A circuit is provided for providing a drive signal. The circuit comprises a live input and a neutral input, an output for providing a drive signal, a master logic gate. The first output is connected to the master logic gate output. A dc signal is connected to the input of the master logic gate so that the output of the master logic gate changes when the state of the input changes. A shunt is connected to the live input and is capable of being switched into and out of the circuit in response to the live input voltage changing from positive to negative with respect to the neutral input voltage and vice versa. The shunt is also arranged to provide a short circuit for the dc signal to bypass the input of the master logic gate.

Abstract: An alternating current motor control system constituted of: a control unit; a cycloconverter functionality; a phase control functionality; and a semiconductor switching unit comprising a plurality of electronically controlled semiconductor switches each associated with a particular winding of a target alternating current motor and each independently responsive to the control unit. In one embodiment the semiconductor switching unit is arranged to connect the windings of the target alternating current motor to a three phase power input in one of a star and a delta configuration responsive to the control unit.

Abstract: A digital control switching power supply unit converts an input voltage into a desired output voltage using a digitally controlled pulse width modulation (PWM) signal according to a switching cycle. The power supply unit includes an analog-to-digital converter (ADC). The ADC converts a result of a comparison between an output voltage and a reference voltage to a digital signal during a conversion cycle. The ADC includes a circuit for outputting a phase difference between a switching cycle and the conversion cycle, and a delay circuit. The delay circuit generates a delay output current based on a result of the comparison and the phase difference and determines the conversion time delay according to the delay output current. The delay circuit also generates a delay reference current based on the reference voltage and the phase difference and determining the duration of the conversion cycle according to the delay reference current.

Abstract: A universal-voltage discrete input circuit uses a high voltage depletion-mode field effect transistor in combination with a low-voltage, adjustable precision shunt regulator and an isolation circuit for interfacing a low voltage digital logic circuit to a switched external voltage ranging from about 7 volts to about 1000 volts AC or +/?DC, at a low fixed current. In addition to the wide input voltage range accepted at a uniform low current value, very high voltage isolation is provided between the external voltage and the low voltage digital logic circuit, and elimination of ground loops and common mode noise.

Abstract: A power factor correction circuit includes a first rectifier to rectify an AC voltage, a series circuit connected to an output of the first rectifier and including a step-up reactor and a switching element, a rectifying-smoothing circuit connected to both ends of the switching element and including a second rectifier and a smoothing capacitor, an input voltage detector to detect an output voltage of the first rectifier, an output voltage detector to detect a voltage across the smoothing capacitor, an error amplifier to amplify an error between the output voltage signal and a reference voltage, and a controller to determine an ON/OFF duty ratio of the switching element according to the amplified error signal and a result of a calculation carried out on the input voltage signal and output voltage signal.

Abstract: A power supply is provided, which includes a DC-DC converter being supplied with an external DC input voltage and a first switching control signal and outputting a duty sensing signal of which a magnitude is varied in accordance with the first switching control signal, the duty sensing signal being indicative of a duty ratio of the first switching control signal, and the DC-DC converter converting the input voltage into a DC output voltage of a predetermined magnitude based on the first switching control signal; and a feedback controlling unit comparing the duty sensing signal with a first reference signal to adjust the duty ratio of the first switching control signal.

Abstract: A light emitting component can include a substrate, a light emitting device supported by the substrate, wherein the light-emitting device has first and second terminals, and a switching element supported by the substrate and having first and second terminals electrically connected to the first and second terminals of the light-emitting device, respectively. The switching element is configured to, at least in part, divert at least some current away from the light emitting device when the switching element is in a closed state. An electrical connection between the first terminal of the switching element and the first terminal of the light emitting device can have a length of less than 5 cm (e.g., less than 2 cm, less than 1 cm, less than 5 mm, less than 1 mm). A current regulator may be supported by a second substrate and can supply current to the light emitting device.

Abstract: According to an exemplary embodiment, a shunt circuit includes a floating shunt switch configured to bypass at least one load, for example at least one LED, among a plurality of series-connected loads, such as a plurality of series-connected LEDs in a lighting system, responsive to a high-side control signal. The at least one load has terminals connected across the shunt circuit. The shunt circuit further includes a high-voltage level-shift up circuit configured to shift a low-side control signal up to the high-side control signal using a voltage of at least one of the terminals of the at least one load. The floating shunt switch can be configured to bypass the at least one load responsive to a failure of the at least one load.

Abstract: A power converter includes an input unit, an output unit, first and second capacitors connected in series, a first electric conduction control device, a second electric conduction control device, a third electric conduction control device, and a fourth electric conduction control device, and a control circuit for performing on/off control on those electric conduction control devices. The first electric conduction control device and the fourth electric conduction control device have a first path through which a current flowing between the input unit and the output unit is allowed to flow in one direction, and a second path which has a switch function of allowing the current flowing between the input unit and the output unit to flow through or shutting off such a current.

Abstract: An IGBT/FET-based energy savings device, system and method (1) wherein a predetermined amount of voltage below a nominal line voltage and/or below a nominal appliance voltage is saved, thereby conserving energy. Phase input connections (2) are provided for inputting analog signals into the device and system (1). A magnetic flux concentrator (3) senses the incoming analog signal (20) and a volts zero crossing point detector (5) determines the zero volts crossing point (21) of the signal (20). The positive half cycle (22) and negative half cycle (23) of the signal (20) are identified and routed to a digital signal processor (10) for processing the signal (20). The signal (20) is reduced by pulse width modulation and the reduced amount of energy is outputted, thereby yielding an energy savings for an end user.

Abstract: A shunt regulator for stepping down an input potential to an output potential, has an input for applying the input potential, an output for tapping off the output potential and a voltage drop circuit, across which the voltage difference between the input potential and the output potential drops. It is possible for the current flowing through the voltage drop circuit or its lower and/or upper limit value to be adjusted.

Abstract: A TRIAC/SCR-based energy savings device, system and method (1) wherein a predetermined amount of voltage below a nominal line voltage and/or below a nominal appliance voltage is saved, thereby conserving energy. Phase input connections (2) are provided for inputting analog signals into the device and system (1). A magnetic flux concentrator (3) senses the incoming analog signal (20) and a volts zero crossing point detector (5) determines the zero volts crossing point (21) of the signal (20). The positive half cycle (22) and negative half cycle (23) of the signal (20) are identified and routed to a digital signal processor (10) for processing the signal (20). The signal (20) is reduced by pulse width modulation and the reduced amount of energy is outputted, thereby yielding an energy savings for an end user.

Abstract: An adjustable shunt regulator circuit has two current paths in parallel, with each current path having a bipolar transistor therein with the bases of the bipolar transistors of the two current paths connected in common. One of the current paths has a high impedance node. A MOS transistor has a gate connected to the high impedance node, and a source and a drain. A resistor divide circuit is connected in parallel to the source and drain of the MOS transistor and provides the output of the regulator circuit. The resistor divide circuit has a first resistor connected in series with a second resistor at a first node. A feedback connects the first node to the bases of the bipolar transistors connected in common of the two current paths.

Abstract: A synchronous boost DC/DC conversion system comprises an input for receiving a DC input voltage, an output for producing a DC output voltage, a power switch controllable to adjust an output signal of the conversion system, and an inductor coupled to the input. A synchronous rectifier is configurable to create a conduction path between the inductor and the output to provide the inductor discharge. A control circuit is provided for controlling the synchronous rectifier as the input voltage approaches the output voltage, so as to adjust average impedance of the conduction path over a discharge period of the inductor.

Abstract: A two-wire load control device, such as a dimmer, is operable to control the amount of power delivered to an electrical load, such as a magnetic low-voltage (MLV) load, and comprises a bidirectional semiconductor switch, a timing circuit, a trigger circuit having a variable voltage threshold, and a clamp circuit. When a timing voltage signal of the timing circuit exceeds an initial magnitude of the variable voltage threshold, the trigger circuit is operable to render the semiconductor switch conductive, reduce the timing voltage signal to a predetermined magnitude less than the initial magnitude, and to increase the variable voltage threshold to a second magnitude greater than the first magnitude. The clamp circuit limits the magnitude of the timing voltage signal to a clamp magnitude between the initial magnitude and the second magnitude, thereby preventing the timing voltage signal from exceeding the second magnitude.

Abstract: A switching circuit approximating the fast switching characteristics and small forward voltage drop of an ideal diode is provided. The switching circuit may include a voltage multiplier circuit, a reservoir capacitor and a pull up switch configured to be coupled to the control terminal of a semiconductor switch.

Abstract: A control apparatus for controlling a fuel pump includes: an electronic switch provided in a circuit for connecting a power supply to a motor for driving the fuel pump; a current detector which detects a current which flows through the motor; and a controller which controls the electronic switch in a first PWM mode of a first frequency and a first duty ratio in a normal operation; and change a PWM mode to control the electronic switch in a second PWM mode of a second frequency lower than the first frequency and a second duty ratio lower than the first duty ratio when the current flowing through the motor exceeds a threshold current value in the normal operation.

Abstract: An overcurrent detection circuit (50 in FIG. 1) in a DC-DC converter is connected to a switching control circuit (1), and detects an inductor current flowing through an inductor (L) during the ON control of a switching element (Mn), so as to decide whether the inductor current has decreased down to a prescribed value. The switching control circuit (1) alters the switching timing of a control signal to extend the OFF state of a switching element (Mp) until the decrease of the inductor current to a predetermined magnitude is decided by the overcurrent detection circuit (50). Even when a delay is involved in an overcurrent detection operation, the DC-DC converter is still capable of overcurrent limitation.

Abstract: A modular power distribution system comprises a chassis; and a backplane including a power input, and a plurality of module connection locations. A plurality of modules are mounted in the chassis, each module mounted to one of the module connection locations. Each module includes: (i) an OR-ing diode; (ii) a circuit protection device; (iii) a microprocessor controlling the circuit protection device; and (iv) a power output connection location. A circuit option switch is located on each module for setting the current limits for each module. A control module is provided connected to the backplane.

Abstract: A power supply input circuit includes an input node configured to removeably couple to an electrical source. A solid state switch is coupled between the input node and a capacitive load. An RC soft start circuit is coupled to the input node and the switch. The soft start circuit has a capacitor that causes the switch to increasingly pass electrical power from the source to the load as the capacitor charges from the source. An active reset circuit is coupled to the soft start circuit. The reset circuit is configured to detect when the source is removed from the input node and in response to the source being removed from the input node, the reset circuit discharges the capacitor to reset the soft start circuit.

Abstract: A freewheeling MOSFET is connected in parallel with the inductor in a switched DC/DC converter. When the freewheeling MOSFET is turned on during the switching operation of the converter, while the low-side and energy transfer MOSFETs are turned off, the inductor current circulates or “freewheels” through the freewheeling MOSFET. The frequency of the converter is thereby made independent of the lengths of the magnetizing and energy transfer stages, allowing far greater flexibility in operating and converter and overcoming numerous problems associated with conventional DC/DC converters. For example, the converter may operate in either step-up or step-down mode and may even transition for one mode to the other as the values of the input voltage and desired output voltage vary.

Abstract: A digital circuit implementing pulse width modulation controls power delivered in what one can model as a second order or higher order system. An exemplary control plant could embody a step-down switch mode power supply providing a precise sequence of voltages or currents to any of a variety of loads such as the core voltage of a semiconductor unique compared to its input/output ring voltage. One of several algorithms produce a specific predetermined sequence of pulses of varying width such that the voltage maintains maximally flat characteristics while the current delivered to the load from the system plant varies within a range bounded only by inductive element continuous conduction at the low power extreme and non-saturation of the inductor core at the high power extreme.

Abstract: A rotating electrical machine control device includes an inverter; a resolver; a unit; a three-phase/two-phase modulation switching unit; and a motor control unit that switches to a two-phase modulation in a specific region where an electric noise given to the resolver by a rotating electrical machine is large, even in a region where the modulation ratio is smaller than the three-phase/two-phase modulation switching boundary.

Abstract: The control circuit comprises: a detecting portion COMP1 for detecting a status transition of a first signal FR at the connecting point P which changes at a constant cycle corresponding to current flowing through the antiparallel diode D when the main switch device FET is turned OFF; and a phase difference adjusting portion 30, 40 for adjusting the phase difference by adjusting the output timing of the second signal FP corresponding to a phase difference between the phase of the first signal FR detected by the detecting portion COMP1 and the phase of the second signal FP generated based on the first signal of one cycle before and the rectification switch device FET2 is turned ON corresponding to the second signal FP whose output timing is adjusted by the phase difference adjusting portion 30, 40.

Abstract: A snubber circuit for a chopper circuit has at least one chopper transistor with terminals connected to a first line and to a second line, the first line being at a power supply potential and the second line being at ground potential. The snubber circuit has a capacitive element and a charging diode for charging the capacitive element. The charging diode and the capacitive element are connected in series to each other and together they are connected in parallel with the chopper transistor. The snubber circuit has an inductive element having a first end connected to a connection point situated between the charging diode and the capacitive element, and a second end connected to one of the lines.

Abstract: The torque control circuit of a hand tool contains a motor driving circuit, a current detection circuit, a reference voltage generation circuit, a current limiting circuit, and a torque configuration circuit. In the last stage of operation of the hand tool and when the average current has reached a predetermined level, the average current is maintained for a period of time to provide a constant average power and therefore to achieve an appropriate tightness of the bolt or nut being operated. The detection and control of current is achieved by a linear circuit which is robust to the heavy noises produced by the motor. A microprocessor is adopted to consider factors such as temperature in determining a suitable current level.

Abstract: A delay applied to a turn-on time for a high side switch in a switch mode power converter prevents oscillation between continuous and discontinuous conduction modes under light load conditions. The delay equalizes turn-on time for a high side switch with respect to continuous and discontinuous modes, so that turn-on time is not treated differently between the different modes. The delay value can be set for be equivalent to a propagation delay through a driver for a low side switch, in addition to a turn-off time for the low side switch. The addition of the delay element tends to maintain the switch mode power converter in a discontinuous mode under light load conditions and avoids oscillation between discontinuous and continuous conduction modes.

Abstract: A current-mode switching regulator uses adaptive current sensing to reliably monitor an inductor current in a cost-efficient and power-efficient manner. A semiconductor switch periodically turns on to conduct the inductor current. A voltage drop across the semiconductor switch is monitored when the semiconductor switch is on. A variable gain amplifier with an automatic gain control loop generates a feedback signal from the voltage drop of the semiconductor switch when conducting to provide an indication of the inductor current to a controller. The automatic gain control loop compensates for any variations in the on-resistance of the semiconductor switch.

Abstract: A switching regulator having first and second power switches. The first power switch has at least two transistors connected in series, the transistors having a first maximum voltage across their terminals which is less than the input voltage of the regulator. The transistors have at least a first node at the point where they are connected, and a first control circuit controls the voltage at the first node so that the voltages across the terminals of the transistors of the first power switch do not exceed the first maximum voltage. The second power switch also has at least two transistors connected in series, the transistors having a maximum voltage across their terminals that is less than the input voltage. The transistors have at least a second node at the point where they are connected, and a second control circuit controls the voltage at the second node so that the voltages across the terminals of the transistors of the second power switch do not exceed the second maximum voltage.

Abstract: A power conversion circuit operates in a discontinuous switching mode over a wide range of loading conditions and varies a coil peak current to maintain efficiency over the wide range of loading conditions. The coil peak current is adjustable based at least in part on a feedback signal generated in response to a load condition.