Abstract: In a complex AC power distribution network (e.g. CATV), a switching mode power supply at a node, automatically operates in a first mode when the input AC power is at a lower potential and operates in a second mode when the input AC power is at a higher potential. A controller switches between modes of operation depending on the input voltage and on the current mode of operation to proved stable switching between modes which in turn provides stable output voltage from the power supply.

Abstract: A method and apparatus for automatically controlling integrated circuit supply voltages includes, according to one embodiment, a primary voltage regulator and a secondary voltage regulator. The primary voltage regulator supplies one of either a first voltage or a second voltage to a first plurality of inputs of an integrated circuit. The secondary voltage regulator conditionally supplies a third voltage to a second plurality of inputs of the integrated circuit in the event the primary voltage regulator supplies the first voltage, with the third voltage being substantially the same as the second voltage.

Abstract: In a direct-current power supply system, an alternating current outputted from an AC power supply is converted by a second diode bridge circuit into a direct current. The direct current is smoothed by voltage doubler capacitors and a smoothing capacitor. A reactor is inserted into an input side of the second diode bridge in series. Detecting circuit is operatively connected to the AC power supply for detecting a zero-crossing point. When the zero-crossing point is detected by the detecting circuit, control means is adapted to firstly switch a switching element on for a first predetermined period of time and, after a predetermined delay period of time has passed since the switching element is firstly switched on, adapted to secondly switch the switching element on for a second predetermined period of time.

Abstract: A solar cell power source device is disclosed which optimizes the power output of the solar cell by detecting a maximum power point of the solar cell and controlling the duty cycle of a switching transistor in a switching power converter such that the output current of the solar cell follows the maximum power point. Also shown is a pulse width modulation controller which multiplies the output voltage of the solar cell by the output current of the solar cell to obtain a power detecting signal, samples the power detecting signal during two different sample periods to determine if the power output is decreasing, and modulating the pulses output to the switching transistor of the switching power converter in order to maintain the power output of the solar cell at the maximum power point.

Abstract: In a power control apparatus of a solar power generation system for converting power generated by a solar panel and supplying the converted power to a load, the output voltage and output current of the solar panel are sensed, and, under ordinary conditions, MPPT control is performed so that the solar cells will operate at a maximum output point. If the output power of the solar panel exceeds a predetermined power, a power conversion unit is controlled so as to raise the output voltage of the solar panel, thereby limiting the output power of the solar panel. As a result, excessive power is prevented from being output by the power control apparatus.

Abstract: The present invention relates to a switching device for selecting a voltage between an a.c. voltage and a d.c. voltage using the ground as a reference, meant to be controlled by a two-state signal, using the ground as a reference and of the same sign as the d.c. voltage, including means for adjusting the turn-on time of a switch in the selection of the d.c. voltage.

Abstract: A controllable electron valve for controlling an energy delivered to a load circuit in response to an input power source, comprising a power controller for controlling a voltage across said load circuit, an input current being introduced to said power controller via an input voltage (V.sub.IN) electrode, said input current being generated by said input power source, said input current including a load current and an internal current (I.sub.IN), said load current being output by said power controller to said load circuit, I.sub.IN being output via a switching output; a current controller for maintaining I.sub.IN at a constant value, said current controller having an output coupled to a ground, having an input, and having at least one current control electrode; a voltage threshold controller for outputting a threshold current, said voltage threshold controller having at least one input and at least one output; and a current separator for controlling the passage of I.sub.

Abstract: A controlled output voltage is provided for a switching mode power converter operating in the continuous conduction mode without requiring a feedback path coupled to monitor the output voltage. Instead, a voltage related to the input voltage is monitored. The monitored voltage is compared to a periodic waveform for forming a switch control signal. In the case of a buck converter operating as a voltage regulator, over each period of the periodic waveform, the periodic waveform is representative of the inverse function. In the case of a boost converter operating as a voltage regulator or buck converter operating as a bus terminator or power amplifier, over each period of the periodic waveform, the periodic waveform has a linear slope. The switch control signal controls a duty cycle of the power switches. Therefore, switching is controlled in an open loop, rather than in a closed loop.

Abstract: A voltage control apparatus which is robust against disturbances such as variations in solar radiation amount around a solar cell, and has quick response, has a voltage detection unit (4) for detecting the voltage value of a battery power supply (1), a power conversion unit (2) for performing predetermined conversion of electric power supplied from the battery power supply, and supplying the converted electric power to a load or a commercial AC system (3), an output setting unit (5) for setting the output value of the power conversion unit on the basis of the voltage detection value, and a control unit (6) for controlling the power conversion unit on the basis of the output setting value. The output setting unit is constituted by a target voltage setting unit (51) for setting the target voltage value of the battery power supply, and an output calculation unit (52) for calculating the output setting value on the basis of the deviation between the voltage detection value and the target voltage value.

Abstract: In a driver of a CCFL for lightening the CCFL by using a piezoelectric transformer, a current supplied from a power source or a power consumption of the CCFL is detected and the piezoelectric transformer is on-off driven at a frequency different from an operating frequency of the piezoelectric trabsformer by a pulse width modulation signal having a duty cycle ratio corresponding to the detected value. The current supplied from the power source does not exceed a predetermined value, so that a capacity of the power source can be small and thus the cost of the power source can be reduced.

Abstract: In a piezoelectric transformer driving circuit which comprises a boosting circuit (2) for boosting an input direct current voltage, a piezoelectric transformer (3), a current voltage converting circuit for converting a load alternating current which flows in the load (9), and a rectifier circuit (5), an input voltage detecting and comparing circuit (10) compares the input direct current voltage with a minimum voltage which is determined by a setting value of the load alternating current to produce a first voltage having a high level when the input direct current voltage is lower than the minimum voltage and to produce a second voltage having a low level when the input direct current voltage is higher than the minimum voltage. A reference voltage producing circuit (6a) produces one of first and second reference voltages in response to one of the first and second voltages.

Abstract: An improved power supply apparatus for controlling electrical elements of a vehicle which is used for a vehicle using 12 volts as well as a vehicle using 24 volts. The apparatus includes a mode selection switching unit which is selectively switched in accordance with a voltage level inputted from a battery, a first voltage transformation unit, which is not operable when the mode selection switching unit is in the turned-on mode and is operable when the mode selection switching is in the turned-of mode, for dropping an input voltage from the battery to a predetermined level, and a second voltage transformation unit for dropping a voltage from the battery when the mode selection switching unit is in the turned-on mode and dropping an output voltage from the first voltage transformation unit to a predetermined level when the mode selection switching unit in the turned-off mode.

Abstract: In order to extract maximum power from a solar cell, maximum power point tracking (MPPT) control is performed under ordinary circumstances. If the output current of the solar cell becomes too small, the operating point of the solar cell is caused to fluctuate over a range wider than that of MPPT control at a period longer than that of MPPT control and the output voltage and current of the solar cell is sampled. In a case where it is indicated by power values obtained from the sample voltage values and current values that a plurality of maximal points of power value exist, a voltage value corresponding to a power value indicative of the largest value is set as the operating point of the solar cell.

Abstract: A maximum power point detecting circuit is disclosed including: a power detector for generating a power detecting signal responsive to an output voltage and an output current of a solar cell; a comparator for comparing a previous power average value with a current power average value according to the power detecting signal for a constant time; and a discriminator for latching an output signal of the comparing means immediately after a current constant time, setting an output immediately before a previous constant time, and judging that an output power of the solar cell decreases when the current power average value is smaller than the previous power average value to generate a discriminating signal.

Abstract: A voltage regulator for regulating a power source that supplies an input signal includes input terminals connected across the power supply, a voltage sensor, a reference generator, a variable load unit, and a control unit. The voltage sensor is connected across the input terminals and receives the input signal and generates a scaled input signal from the input signal that is a fraction of the input signal in magnitude. The reference generator receives the scaled input signal from the voltage sensor and generates a reference signal. The variable load unit is connected across the input terminals. The control unit receives and compares the scaled input signal and the reference signal and instructs the variable load unit to dissipate a first portion of the input signal if the scaled input signal exceeds the reference signal.

Abstract: An apparatus and method is provided for controlling electrical power from a power source to electrical loads in response to a decrease in power source voltage. A power source signal is compared to a predetermined signal voltage to determine whether and how much the voltage of the power source signal has decreased below that of a predetermined signal. A fraction of electrical power from the power source is transmitted to the loads as a function of how much the voltage of the power source signal has decreased below that of the predetermined signal.

Abstract: The invention provides a stabilized power converter having an input voltage and an output voltage, where the stabilized converter operates similar to a conventional converter under normal conditions, and operates continuously at the maximum power transfer point during overload conditions. The stabilized converter comprises a voltage control loop for regulating output voltage, and a stabilization loop for regulating input voltage. In a preferred embodiment, the stabilization loop senses the input voltage to the stabilized converter and compares it to a reference voltage. Whenever converter input voltage is above the maximum power transfer voltage, no action is taken by the stabilization loop, and the converter operates in the conventional manner. As converter input voltage approaches the maximum power transfer voltage, converter output voltage and corresponding converter input and output power are reduced to compensate.

Abstract: Power supplied from a battery power supply to a load through a power conversion unit is maximized with a relatively simple arrangement and a small processing load. In addition, an output command value for controlling the power conversion unit is detected, a set voltage for which the output command value is maximized is calculated with reference to a past or present set voltage, as needed, and set as the next set voltage such that the maximum output is supplied to the load without any erroneous operation in the case of variation in solar radiation. In this case, a plurality of voltages are sequentially set for a relatively short period. Output command values for the respective set voltages are fetched while setting the same voltage at the start and end of the operation. A variation in output command value caused by the fetching difference for the same set voltage is detected. The output command value for calculating the next set voltage is corrected in accordance with this variation.

Abstract: A power supply self adjusted circuit that can sense a power supply voltage and detect whether the power supply is of a first value (e.g., 5V) or a second value (e.g., 3.3 V). In the case of a modem system, the power supply self adjusted circuit then adjusts the modem system accordingly. Hence, using this circuit, a modem or other signal processing circuit can be designed to work for both 5V and 3.3V power supply systems, for example. Futhermore, the power supply self adjusted circuit enables a modem system to automatically adjust itself when the power supply is switched from 5V to 3.3V or vice versa, without any manual intervention from the user. This capability is important for increasingly-popular PC Card- modems.

Abstract: A method and apparatus for automatically controlling integrated circuit supply voltages includes, according to one embodiment, a primary voltage regulator and a secondary voltage regulator. The primary voltage regulator supplies one of either a first voltage or a second voltage to a first plurality of inputs of an integrated circuit. The secondary voltage regulator conditionally supplies a third voltage to a second plurality of inputs of the integrated circuit in the event the primary voltage regulator supplies the first voltage, with the third voltage being substantially the same as the second voltage.

Abstract: Efficient very low dropout (i.e., approximately equal to about V.sub.CESAT of the output transistor) dual supply voltage regulator circuits and methods are provided. The voltage regulators are capable of providing very low dropout irrespective of supply sequencing. Traditional supply sequencing problems are overcome by including an anti-latch circuit that monitors the output power supply during power-on. The anti-latch circuit is also coupled to any location in the regulator circuit where the drive current can be inhibited whenever the output power monitor senses that the output power supply is not fully operational. The anti-latch circuit operates to prevent drive current from being supplied to the output transistor unless output power is available so that the substrate of the regulator is not permitted to become forward biased (and thus prevents the establishment of an undesired latch condition).

Abstract: A solar cell system for supplying electric energy from solar cells to loads. This solar cell system includes solar cells for converting light energy into electric energy, an electric double layer capacitor for storing the electric energy from the solar cells, and a discharge controller for causing the electric double layer capacitor to discharge electric energy to the loads intermittently in predetermined cycles while charging the electric double layer capacitor. A period of time for discharging is shorter than a period of time for charging, and a current discharged to the loads is larger than a charging current applied to the electric double layer capacitor.

Abstract: This invention solves various problems of an inverter device caused by a winding transformer by using a piezoelectric transformer, and also provides a drive device for a cold cathode tube using a piezoelectric transformer so as to enable lighting and light control of the cold cathode tube. In a cold cathode tube lighting device having a cold cathode tube and piezoelectric circuit to light the cold cathode tube, a series resonance circuit is formed at primary side of the piezoelectric transformer. An operation control device is installed for ON-OFF control of the series resonance circuit, by a switching element, at timing with the phase advanced from the resonance frequency of the resonance circuit, and a chopper circuit for stepping-up the input voltage and supplying a power source to the resonance circuit is installed, and ON-OFF control of the power switching element of the chopper circuit is performed by the operation control device.

Abstract: First and second analogue signal processing circuit has first to fourth input terminals and first and second output terminals, and functions such that the first and second output terminals have an equal potential and that a difference between output currents of the first and second output terminals is proportional to a product obtained by multiplying a potential difference between the first and second input terminals by a potential difference between the third and fourth input terminals. The first input terminal of the first analogue signal processing circuit is supplied with an input signal, and the second input terminal is supplied with ground potential. The third input terminal is supplied with a second reference potential, and the fourth input terminal is supplied with a third reference potential. The first input terminal of the second analogue signal processing circuit is supplied with an output signal from an operational amplifier, and the second input terminal is supplied with the ground potential.

Abstract: The invention relates to a voltage generator including a fuel cell, a d.c. converter and a storage battery, the input terminals of the d.c. converter being connected to the fuel cell terminals and the output terminals of the d.c. converter being connected on the voltage generator terminals in parallel with those of the battery. A microprocessor regulates the maximum intensity value of the current going through the d.c. converter responsive to the voltage measured at the terminals of the fuel cell in order to maintain the voltage near a preset reference value.

Abstract: The electric energy generated by a piezoelectric device (PEG), when mechanically stressed, is transferred from the PEG to a storage element (e.g., a capacitor or a battery) by selectively coupling an inductor in the conduction path between the PEG and the storage element. In one embodiment, the transfer of energy is optimized by allowing the amplitude of the electric signal to reach a peak value before transferring the electrical energy via an inductive network to a capacitor or a battery for storage. Electrically, the PEG is operated without a significant loading (e.g., essentially open circuited) when the amplitude of the voltage generated by the PEG is increasing. When the amplitude of the voltage has peaked, or reached a predetermined value, the electrical energy generated by the PEG is coupled to an inductive-capacitive network for absorbing and storing the energy produced by the PEG.

Abstract: A system supplies power to and controls the frequency of electronic circuitry. The system comprises a DC source for supplying power to the electronic circuitry and a voltage controlled oscillator powered by the DC source. An output of the oscillator provides a system clock for the electronic circuitry such that as a voltage of the DC source continuously drops, the operating voltage of the electronic circuitry and oscillator continuously drops and the frequency of the system clock continuously drops in a manner corresponding to the continuous drop in operating voltage. Thus, the oscillator supplies an operating frequency tailored to the operating voltage to permit the electronic circuitry to operate at high speed.

Abstract: A power control method and apparatus for extracting the maximum power from a battery power source are disclosed. Voltage signals and current signals are read while varying the operating point of a solar cell acting as the battery power source. The variation in the intensity of solar radiation that has occurred during a sampling time interval is estimated from a plurality of current signals, sampled at the same voltage, or, according to a plurality of power values, calculated from current signals and voltage signals. Based on the estimated variation in the intensity of solar radiation, the current signals or power signals are corrected. According to the corrected current signals or according to the corrected power values and the voltage values, the operating point is controlled so that the maximum output power is provided from the solar cell.

Abstract: An uninterrupted power supply with improved circuit arrangement includes a controller, a detecting circuit and a control circuit. When the incoming AC voltage is normal and in a positive half-wave cycle, an input pin of the controller detects the actual voltage level of the secondary voltage of a transformer. When the incoming AC voltage is in a negative half-wave cycle, the input pin of the controller receives a sinusoidal input waveform voltage based on the voltage Vcc which acts as a reference voltage, and the controller processes the sinusoidal input waveform voltage by subtracting the secondary voltage of the transformer from the voltage reference Vcc to obtain a sinusoidal half-wave voltage with positive half-wave cycle. The controller combines the positive and negative half-wave cycle signals to obtain a composite voltage, and then calculates the RMS value of the composite voltage so as to determine the changing situation of the incoming AC voltage.

Abstract: The present invention limits the rate of variation of electrical consumption in a device composed of a circuit employing a semiconductor element in which electrical consumption varies according to the amount of change in circuit state by supplying a dummy signal to the circuit when the standard input circuit is cut off and by using a dummy signal to cause electrical consumption to gradually increase at the time of recovery of the standard input signal.

Abstract: An improved power factor DC power supply in accordance with the present invention (100 or 200) employs a power factor correcting network (120), a full-wave rectifier means (122), a pair of filter capacitors (124 and 126), and three current steering diodes (128, 130 and 132). The power factor correcting network (120) includes both an inductor means (136 and 240) and a capacitor (138), the combination configured to improve the power factor DC power supply (100 or 200) presents to the AC power-line (102) by reducing the level of harmonic currents the DC power supply generates on the AC power-line. The filter capacitors (124 and 126) are configured with the current steering diodes (128, 130 and 132) such that the filter capacitors are charged in series and discharged in parallel.

Abstract: Main power supply circuit includes an inrush current suppressing circuit serially connected between its rectifying circuit and a load, this inrush current suppressing circuit being composed of a current limiting resistor and an FET switch that is serially connected to this resistor. An auxiliary power supply circuit provides power for a control circuit of the main power supply circuit, and, after the power supply switch is closed, a delay circuit monitors rise of a charge voltage of a smoothing capacitor within the main power supply circuit as well as rise of control circuit voltage of the auxiliary power supply circuit and establishes a delay time. After the elapse of the delay time, the FET switch is turned ON and the inrush current suppressing circuit is closed. The inrush current suppressing circuit is then short circuited within a short time period and the load operation is continued.

Abstract: A voltage regulator circuit having one input to receive a voltage to be limited, this input being connected to a ground by means of a limiting transistor. To control this transistor, a comparator and a dissymetrical differential stage are used. The differential stage receives the voltage to be limited and a reference voltage produced by means of a Zener diode, and supplies the comparator with voltages lower than those that it receives. The output of the comparator is connected to the control gate of the limiting transistor. This regulator circuit can advantageously be used to regulate a voltage produced by a voltage multiplier within an electrically programmable memory.

Abstract: A controllable electron valve for controlling an energy delivered to a load circuit in response to an input power source, comprising a power controller for controlling a voltage across said load circuit, an input current being introduced to said power controller via an input voltage (V.sub.IN) electrode, said input current being generated by said input power source, said input current including a load current and an internal current (I.sub.IN), said load current being output by said power controller to said load circuit, I.sub.IN being output via a switching output, a current controller for maintaining I.sub.IN at a constant value, said current controller having an output coupled to a ground, having an input, and having at least one current control electrode; a voltage threshold controller for outputting a threshold current, said voltage threshold controller having at least one input and at least one output; and a current separator for controlling the passage of I.sub.

Abstract: A motor drive particularly suited for decelerating an AC motor includes a signal converting circuit, a monitoring circuit and a control circuit. The signal converting circuit is coupled to a source of DC power via a DC bus and a capacitive circuit is coupled across the DC bus to store energy produced by the motor during deceleration of a primarily inertial load. The signal converting circuit produces and applies drive signals to the motor based on control signals from the control circuit. The control circuit produces control signals for generating an output waveform duty cycle for the drive signals suitable for maintaining a predetermined voltage-to-frequency relationship. The frequency of the output signals is selectable to control the output speed of the motor. During deceleration, the monitoring circuit detects rises in the DC bus voltage, indicating that the motor is tending to slow at a rate less than the desired deceleration rate.

Abstract: The invention relates to a switch controller system which furnishes a constant output, voltage over a broad input voltage range. The input voltage may here be lower as well as higher than the output voltage. The large control range is realized by a combination of a down converter and an up converter in a power output stage and a common storage choke. The storage choke is advantageously configured as a flat coil in multi-layer technology and includes a coil core. A novel switch controller system is disclosed which links two known converter concepts having different characteristics with one another.

Abstract: A circuit (10) and method for detecting a fault in a recirculation diode (13) in a switched power supply. The power supply has a switching transistor (12) that is turned on and off by a power supply control device (31), switchably applying a supply voltage (15) to an output (14). The recirculation diode (13) is connected between the output (14) and a reference potential (16). The circuit includes a sense resistor (11) in series between the supply voltage (15) and the switching transistor (12). A biasing element (25) is connected to clamp a current control element of the switching transistor (12) to the reference potential (16) when the switching transistor (12) is switched off so that a fault in the recirculation diode (13) results in a current flowing in the switching transistor (12). An amplifier (33) is connected across the sense resistor (11).

Abstract: A solar water pumping system for home use utilizing amorphous solar panels and circuitry for maintaining proper power to the system. Three reference voltages in combination with switching circuitry achieve this purpose by constantly monitoring input and output voltages and allowing a non-discontinuous switching between solar power and battery power.

Abstract: A method and apparatus for preventing current inrush upon the application of power to a load includes the steps of applying a first increasing DC voltage from a voltage source to the load through a single signal path which includes a transistor having a control electrode coupled to the voltage source and a second electrode coupled to the load. The transistor has a first operating region with an ON resistance characteristic which decreases between first and second applied control voltages. The transistor has a second operating mode in which the transistor has a relatively low on resistance R.sub.ON. The transistor is thus disposed in the single signal path to both limit inrush current and to provide a low loss signal path between the voltage source and the load.

Abstract: A switching power supply in which the oscillation frequency is dynamically controlled to have an instantaneous frequency value which is reduced when the power line waveform is near its peaks. This is preferably accomplished by a divider circuit, which provides an output current proportional to the ratio between the instantaneous value of the rectified voltage and the long-term-averaged value of that voltage. This output current is fed into a ramp generator, to dynamically shift the frequency of the ramp generator as the output current changes. This circuit is indifferent to power line voltage and frequency (over a fairly wide range), and therefore may be used in different countries having different power standards.

Abstract: A device for supplying a power supply voltage to an electronic circuit, in particular to an electronic circuit associated with a current sensor for measuring the electrical current in a high-tension line, comprises a current transformer having a primary circuit and a secondary circuit, a rectifier bridge shunting the secondary circuit and output terminals of the rectifier bridge, a first capacitor in parallel with a first resistor across which said power supply voltage is obtained, and a first switch disposed between the output terminals of the rectifier bridge. It includes between the output terminals of the rectifier bridge a branch comprising in series a second capacitor, a second switch and a second resistor. The first switch is controlled by a first threshold detector shunting the second capacitor. The second switch is controlled by a second threshold detector shunting the first capacitor.

Abstract: Power supply arrangement comprising a direct voltage monitoring circuit. A power supply arrangement comprising a direct voltage monitoring circuit for at least two different-polarity direct voltages connected to a common reference potential, and including a signal transmission element. The monitoring circuit arrangement has an enhanced accuracy of response with limited circuitry and cost. A series connection of a zener diode and a resistor is connected in shunt with each direct voltage. The junction point of each zener diode and resistor is connected to the base of a transistor. A first electrode of each transistor is connected to the signal transmission element and a second electrode.

Abstract: A controlling/driving apparatus for an electrically-driven compressor of an air conditioner mounted in an automobile. The apparatus comprises a DC-AC converting invertor 4 for converting a DC voltage into a pseudo AC voltage (e.g. a pulse train of positive and negative pulses), a DC voltage detector 7, and a pulse width changing unit 8 for changing the width of each pulse of the pulse train in accordance with the DC voltage detected by the DC voltage detector. Thus, the apparatus enables safe and efficient operation of the compressor with improved electric insulation and durability when large fluctuations in the power source voltage of the compressor occur.

Abstract: This electric power supply system includes an air conditioner serving as load, a solar photovoltaic cell for supplying power to the air conditioner, and a system power control circuit and further including a commercial power source for use in combination with the solar photovoltaic cell for supplying additional power when insufficient, power is supplied from the solar photovoltaic cell to the air conditioner. In an operation state of the air conditioner, the system power control circuit operates to regulate an operating point of the solar photovoltaic cell and variably regulate the supplied power from the solar photovoltaic cell while comparing required power of the air conditioner with the supplied power from the solar photovoltaic cell.

Abstract: A peak power tracker apparatus is used for controlling the negative impedance of converter for transferring maximum power from a solar array source to a battery and load typically used in space vehicles, by capacitive differentiation sensing the solar array source voltage for sensing the peak power point at which the source voltage first begins to become unstable and collapses, and then providing a step down control signal which controls a current mode pulse width modulator to control the converter to vary the negative impedance into the solar array then reserving back to a stable point at which the tracker then provide a linear ramp signal to the modulator to control the converter to drive the source voltage again to the peak power point, so as to alternate the feedback loop and source voltage between a stable point and the peak power point so as to transfer maximum power while preventing the source voltage to pass through an unstable point for discontinuous but stable operation at peak power transfer which

Abstract: An input voltage U.sub.IN to a voltage level converter 10 having a high input impedance charges a storage element which periodically discharges current to an LED 16 which periodically provides a light pulse for generating a level converted version of the input voltage U.sub.IN. A resistor R.sub.p 22 connected to the storage element allows the storage element to discharge noise voltage spikes in the input voltage U.sub.IN.

Abstract: An AC-DC converter of a type having an improved power factor having an arrangement that enlargements of loads to be borne by circuit components due to AC input voltage is prevented so that the size and cost of the AC-DC converter are reduced. A constant-current circuit is, in parallel, connected to a voltage dividing point of charge voltage of an output capacitor to be connected to an input terminal of an error amplifier of a booster converter circuit and realized by a plurality of resistors so that control of a constant-current value of the constant-current circuit is performed with the rectified output from the rectifying circuit. As a result, the loads to be borne by the circuit components of the AC-DC converter can be made constant regardless of the supplied AC voltage level so that the size and cost of the AC-DC converter are reduced.

Abstract: Instabilities in the output voltage provided from an AC power supply system connected to a power factor correcting load are suppressed by a stabilizer which is connected across the output lines from the power supply system to the load. The stabilizing apparatus includes a rectifier having AC input nodes connected to the power supply system output lines, and DC output nodes at which DC voltage appears. A capacitor and resistor are connected in parallel across the output nodes of the rectifier. During normal operation, where the peak AC voltage from the power supply system is substantially constant, the capacitor charges up to a voltage level near the zero to peak value of the AC voltage waveform, with the charge on the capacitor slowly dissipated through the parallel resistor at a rate that does not substantially dissipate the charge between peaks of the AC voltage waveform.

Abstract: A boost switching preregulator includes a boost switching power conversion device which converts power from a source of essentially DC unipolar input voltage for delivery as an essentially DC unipolar output voltage to a load. The preregulator also includes a control device which accepts an input indicative of the magnitude of the output voltage and which, in response to variations in the magnitude of the input voltage, controls the boost switching power conversion device such that the magnitude of the output voltage varies within a range. Within this range, the unipolar output voltage is greater than or equal to the magnitude of the unipolar input voltage, and the span of the range is at least ten percent of the maximum value of the unipolar output voltage.

Abstract: A power transfer method and apparatus for efficient transfer of power are disclosed. Input power is converted in an essentially lossless manner to an intermediate form having a voltage or current in excess of that desired at the load. The intermediate power form is split into first and second parts, where the first part of the intermediate power form approximately matches an output power form desired at an output of the power transfer apparatus and the second part represents an excess power form. The first part of the intermediate power form is transferred to the output of the power transfer apparatus and the excess part is stored. Part or all of the stored excess energy is recycled in an essentially lossless manner, converted into a form that approximately matches the output power form desired at the output of the power transfer apparatus and transferred to the output of the power transfer apparatus.