Abstract: The present invention relates to a device for improving the harmonic ratio sent back onto the mains in a rectified power supply including a rectifying bridge and at least one capacitor connected to a first output terminal of the rectifying bridge. Between the second terminal of the capacitor and a second output terminal, a first charge path including a resistor is provided, as well as a second switchable discharge path, associated with means for switching on the discharge path only after the supply voltage has transmitted through a maximum.

Abstract: A current multiplier/divider circuit is provided, which is capable of any one of multiplication and division operations in a current mode without changing its configuration. This circuit includes a first set of m bipolar transistors and a second set of n bipolar transistors, where m.gtoreq.2) and n.gtoreq.2. A base of a (j-1)-th one of the transistors of the first set is connected to an emitter of the j-th transistor of the first set, where 2.ltoreq.j.ltoreq.m. A base of a (k-1)-th one of the transistors of the second set is connected to an emitter of the k-th transistor of the second set, where 2.ltoreq.k.ltoreq.n. A sum of V.sub.BE of the m transistors with respect to a specific electric potential, which is generated at a base of the m-th transistor in the first set, is equal to a sum of V.sub.BE of the n transistors, which is generated at a base of the n-th transistor in the second set.

Abstract: An interleaved flyback electrical power converter system having a plurality of flyback power converters operated in continuous mode, each converter utilizing a power switch operated under zero voltage switching conditions. The interleaved flyback power converter system is highly efficient and compact, and is suitable for use in high power, high frequency applications.

Abstract: A rectifier control system with rectifiers connected in parallel operates constantly by ensuring balance between the rectifiers with respect to output voltage and current. The rectifiers apply a DC voltage to a single DC bus. Current detectors associated with the rectifiers detect the bus current flowing through the DC bus. Voltage control circuits associated with the rectifiers control the DC voltage to coincide with a voltage command value. Command value generating circuits associated with the rectifiers correct the voltage command value with a signal proportional to the detected bus current or a signal obtained by integrating or amplifying the bus current with an amplifier having a first order lag characteristic.

Abstract: A DC-to-DC converter includes a comparator for controlling a high-side switch and has one input connected to a switch signal and another input connected to a peak current reference signal. A comparator bias boost circuit increases a bias to the comparator to provide accurate comparisons even when the switch signal and the peak current reference signal are both relatively close to a voltage of the source. The additional bias may be provided by a voltage which is typically available for a DC-to-DC converter. More particularly, the high-side switch has a terminal defining a phase node, and the additional bias voltage may be provided by a capacitor referenced to the phase node to provide the bias higher than a voltage of the source and responsive to switching at the phase node. The converter preferably further includes one or more clamps for clamping the output of the comparator during a relatively rapid change in the bias. A clock may be used for turning on the high-side switch.

Abstract: The battery charger comprises a power factor correcting and voltage regulating apparatus having an inductor through which current is modulated by a modulator to obtain an efficient regulation and an efficient power factor correction. According to a first embodiment, the modulator comprises two rectifying elements connected to two controllable high frequency bidirectional switch elements. According to a second embodiment, the modulator comprises a rectifying element connected to a controllable high frequency switch. According to a third embodiment, an efficient battery charger is provided. It comprises an inverter including four controllable high frequency bidirectional switch elements connected in a bridge configuration. According to a fourth embodiment, a two-part battery charger is provided. It has an indicator for indicating quality of the coupling between the two parts thereof. According to a fifth embodiment, a two-part battery charger is provided.

Abstract: This invention relates to a reference voltage generator which provides for an optimum control of the output voltage as a function of temperature. The generator comprises two transistors, two current sources, two resistors, and a third transistor supplying current into a charge resistor. It also comprises, connected between the first and second transistors and the current sources, a pair of transistors whose bases are jointly connected to the base of the third transistor.

Abstract: A pulse charging apparatus includes a DC high-voltage generator, a capacitor that is charged by a DC high voltage output from the DC high-voltage generator, a switching unit for switching charges stored on the capacitor to provide a pulse-like high voltage to a load, and a control unit for controlling the operation of the switching unit. The switching unit consists of a series combination of an electron tube and a stationary gap. The control unit controls the operation of the electron tube.

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: An inductive load drive device using a DC--DC converter circuit with which a high voltage is obtained by the discharge of electromagnetic energy stored in a coil to a capacitor, in which a bias is applied to the magnetic core of a coil (L) with the use of a permanent magnet (Mg) in the direction opposite to the magnetic flux induced by a current so as to increase the electromagnetic energy stored in the coil (L) and make it possible to perform efficient discharge with a small coil.

Abstract: The battery charger including a power factor correcting and voltage regulating apparatus having an inductor through which current is modulated by a modulator to obtain an efficient regulation and an efficient power factor correction. According to a first embodiment, the modulator comprises two rectifying elements connected to two controllable high frequency bidirectional switch elements. According to a second embodiment, the modulator comprises a rectifying element connected to a controllable high frequency switch. According to a third embodiment, an efficient battery charger is provided. It comprises an inverter including four controllable high frequency bidirectional switch elements connected in a bridge configuration. According to a fourth embodiment, a two-part battery charger is provided. It has an indicator for indicating quality of the coupling between the two parts thereof. According to a fifth embodiment, a two-part battery charger is provided.

Abstract: A protective device used in switching mode power supply protects the supply during abnormal conditions, such as undervoltage or overvoltage resulting from power supply conditions inconsistent with the rated power supply conditions. During such abnormal conditions, this protective device is operated in a manner that an interrupt generator detects such a condition and interrupts the operation of the supply using an interrupt signal.

Abstract: An improved sub-resonant converter which retains the advantages generally associated with simple series resonant converters while additionally providing improved form factor and efficiency, and reducing EMI. The overall tank circuit includes at least a first inductor and first capacitor connected in series, a second capacitor connected in parallel with the load circuit, and a second inductor connected in parallel with the second capacitor for providing voltage boost capability. In addition to reducing dv/dt in the load circuit, the second capacitor draws a current that has the effect of reducing the form factor of the supplied current while shortening the negative portion of its cycle so that reverse current through the anti-parallel diode of one switching device is terminated, or nearly so, by the turn on of the next switching device, thereby reducing EMI associated with a rapid initial rise in current at such turn on.

Abstract: A bi-directional DC/DC voltage converter having first and second input/output terminals for respectively receiving on a mutually exclusive basis uni-directional current at first and second voltages. A charge pump circuit connected between the first and second input/output terminal, depending on which voltage is supplied, converts that voltage to the other voltage.

Abstract: A controlled power supply source is described, which has a parallel control member having a controllable semiconductor component whose load path is arranged between output terminals of the power supply source and whose control input is connected to an output of a control device, the control device having a reference input for supplying a reference voltage. The control device has a control amplifier which is fed from a current bank having at least one constant current source, an actual value input of said control amplifier receiving the voltage between the output terminals of the power supply source, and a nominal value input receiving the reference voltage from the reference input of the control device.

Abstract: A power supply comprises: a rectifier; a power preconverter coupled to the rectifier; a switched-mode power supply circuit coupled to the power preconverter; and, a phase control circuit for synchronizing operation of the power preconverter with operation of the switched-mode power supply circuit. An energy storage device may be coupled to the power preconverter and to the switched-mode power supply circuit. A preconverter switch conducts during each time interval that a power switch in the switched-mode power supply circuit conducts in order, for example, to charge the energy storage device. The preconverter switch begins conducting only after each time interval begins and always stops conducting before each time interval ends. In a portion of the time interval after the preconverter switch has stopped conducting, a current can flow directly from the power preconverter to the switched-mode power supply circuit without, for example, charging the energy storage device.

Abstract: A primary regulator having a zero-crossing detector and a voltage reference coupled to a processor is provided. The processor controls the on time of a primary transformer via a switching device isolated from the processor via a coupler A method of regulating a power supply to maintain a desired output voltage at a load including the steps of measuring an average output voltage at a load and controlling the on time of a switching device serially connected to a primary transformer input based on the measured output voltage and a zero-crossing signal.

Abstract: Electrical power monitoring apparatus comprises a loop and a first conductor. A current sensor coupled to the first conductor provides a current signal that is representative of the current in the first conductor. A voltage sensor coupled at least to the first conductor provides a voltage signal that is representative of the voltage on the first conductor relative to that on a reference terminal. A multiplier coupled to the current sensor and voltage sensor has a power output which provides a power signal that is proportional to the instantaneous value of electrical power carried by the first conductor. A calibration circuit in the loop has an input coupled to the power output and has an adjustable output. A current regulator in the loop has an input coupled to the adjustable output to maintain the current in the loop between predetermined minimum and maximum loop current values.

Abstract: A current regulator (60, 90, and 100) provides current regulation. The current regulator (60, 90, and 100) has a bias generator (14) which compares a generated voltage, V.sub.ref, with a feedback voltage generated in accordance with an output current provided in a reference circuit (57, 58, and 59). The current regulator (60, 90, and 100) operates as a bias circuit to minimize the quiescent currents for efficiently providing regulated output currents in current sink circuit (26). The current in the bias generator (14) and the current in the reference circuit (57, 58, and 59) that regulate the output current in current sink circuit (26) are a small percentage of the overall current.

Abstract: Apparatus and methods for AC power regulation for a wide range of complex capacitive and inductive loads which provide substantial reduction in power consumption while also providing a leading power factor. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25 percent in lighting loads while producing minimal reduction in light output. The system utilizes a main switch consisting of back-to-back MOS Controlled Thyristor devices (MCTs) and a parallel capacitor bank in series with the load. The main switch is initially turned off slightly in advance of the load current zero crossing, and this in combination with the capacitor bank allows power to be reduced in a low noise fashion. The turn-off time is advanced gradually to regulate power at a target reduced level. At the target power level, load phase angle is measured and maintained to control the power savings ratio.