Abstract: A power supply control circuit generates DC power output intermittently at predetermined intervals during a power saving mode of operation, so as to save power. The power supply control circuit includes an AC power circuit for receiving AC power and for outputting the AC power for a predetermined time; a DC power generator connected to the AC power circuit for converting the AC power into DC power; and a controller receiving a power-on/off signal generated from a power switch, for generating a first power control signal of a first logic state in response to the power-on signal and for generating a second power control signal alternating between the first logic state and a second logic state in response to the power-off signal. The second power control signal alternates between the first and second logic states at predetermined intervals.

Abstract: A multi-output switching power unit which can substantially prevent an output power supply of an auxiliary output power circuit from dropping significantly when a load a is light and which has a reduced loss in the output path. A voltage up capacitor 20, a first diode 21, a second diode 22 and a series regulator 13 are provided in the auxiliary output power circuit 9 including a choke rectifier circuit 4. When the load a is light and an output voltage V2 of the auxiliary output power circuit 9 drops to below the predetermined voltage of the series regulator, the series regulator 13 is put into a conductively connected state.

Abstract: A power conditioning circuit for use in a power supply includes a power input and a power output. The circuit also includes a series connected RFI-EMI filter, rectifier, and SCR between the power input and the power output. The SCR has a control input for switching the SCR on and off, thereby interrupting current flow between the power input and the power output. An energy storage circuit is connected across the power output. Furthermore, the circuit includes a control circuit coupled to the control input of the SCR for switching the SCR on and off to maintain a regulated voltage at said power output in response to an AC input. A conditioned DC output is produced in response to a DC input.

Abstract: A power integrated circuit pre-regulator AC/DC converter circuit which employs a slow turn-off lateral insulated gate bipolar transistor (LIGBT) device as the switching transistor so as to reduce the decay time of a current generated by the parasitic inductance in the circuit upon turn-off of the LIGBT device, thereby to substantially reduce the level of a ringing voltage produced at the drain of the LIGBT device.

Abstract: An uninterruptible power supply, with passing neutral, comprises a twin step-up chopper whose input is connected to a battery and to a rectifier circuit connected to the mains power system. The twin step-up chopper comprises a positive step-up chopper supplying a first output voltage between a positive DC output and neutral, and a negative step-up chopper supplying a second output voltage between a negative DC output and neutral. The control circuit of the twin step-up chopper comprises means for regulating imbalance between the output voltages of the positive and negative step-up choppers, suitable both for operation on the mains power system and for operation on the battery.

Abstract: A power supply is disclosed which is compatible with modern thin film technology which has an overall size compatible with modern miniaturized electronic components. Input power having an oscillating component in the 50/60 Hz 120/220 volt range is immediately switched to high frequency current exceeding 100 KHz and preferably switched with a frequency in the megahertz range. The switched current, otherwise unaltered from its current having an oscillating component, is then transduced in voltage at a thin film transformer, passed through thin film mounted electronic components for rectification and filtering. A regulator circuit modifies the semi-conductor switch duty cycle to control the rectifier output voltage. All transformer, rectifier, and filter components are of thin film variety and mounted to attain efficient heat dissipation together with size reduction comparable to the powered components driven by the power supply.

Abstract: A power supply is disclosed which is compatible with modern thin film technology which has an overall size compatible with modern miniaturized electronic components. Input power having an oscillating component in the 50/60 Hz 120/220 volt range is immediately switched to high frequency current exceeding 100 KHz and preferably switched with a frequency in the megahertz range. The switched current, otherwise unaltered from its current having an oscillating component, is then transduced in voltage at a thin film transformer, passed through thin film mounted electronic components for rectification and filtering. A regulator circuit modifies the semi-conductor switch duty cycle to control the rectifier output voltage. All transformer, rectifier, and filter components are of thin film variety and mounted to attain efficient heat dissipation together with size reduction comparable to the powered components driven by the power supply.

Abstract: An intermittent on/off regulator type DC power supply circuit having low noise and low losses includes a voltage detector at the power source side of the circuit and/or a current detector at the load side of the circuit which feeds back voltage and or current values to a central controller and intermittently cuts off the input or output of a transformer or rectifier whenever preset voltage or current levels are exceeded thereby preventing, for example, overcharging of a battery.

Abstract: An electrically variable current limiting reactor which is usable in association with a power supply for an electrostatic precipitator is disclosed herein. The current limiting reactor is capable of having the inductance value thereof varied responsive to system operation conditions. Most particularly the inductance of the current limiting reactor can be modified responsive to the form factor of the sinusoidal AC input current to the power supply transformer. Additionally the inductance of the current limiting reactor can be controlled responsive to the fractional conduction of the full wave rectified current waveform at the output of the full wave rectifier of the power supply. Other conditions can be monitored to control the inductance value of the current limiting reactor such as physical system parameters. An automatic operating control may modify the inductance of the current limiting reactor responsive to the current entering the primary of the transformer of the power supply.

Abstract: A power converter comprises a power stage including a transformer, a pulse width modulator (PWM) for controlling the power stage, multiple output circuits providing individually regulated voltages, including switches for coupling the output circuits sequentially and cyclically to the power stage, and feedback circuitry for supplying respective feedback signals, each for a respective output circuit, as a control signal to the PWM synchronously with the coupling of the output circuits to the power stage, so that a single PWM and power stage serve for multiple output circuits. The converter can be a dc to dc converter or a four-quadrant switching amplifier. The PWM operates in current mode in conjunction with a current sensing resistor or transformer.

Abstract: A high frequency power supply for supplying a yielding current through a choke to a welding station including an electrode element and a workpiece element, wherein the power supply includes a transformer means for creating a first current pulse in a first secondary winding and a second current pulse in a second secondary winding and means for connecting said secondary windings to pass said current pulses through said choke and across said elements.

Abstract: A differential charging circuit comprising an active switch device controlled by a differential trigger circuit and a current impedance device to charge a storage battery through an intermediate storage capacitor. A capacitor and commutating inductance are also connected in series with the output to reduce ripple. The differential active switch device is controlled based on a reference potential developed across the current impedance device, and this enables frequency-controlled charging of the storage battery through the commutating type inductance.

Abstract: A power converter, based on a modular architecture, in which a boost power factor correction circuit is provided as an input stage for both a primary power source and a battery power source. This arrangement permits the same power conversion stages which follow the boost power factor correction circuit to be used regardless of whether the primary or battery power source is in use. The power supply includes a controller for monitoring the primary power source voltage and the DC voltage produced at the output of the boost circuit and comparing each to a preselected reference. When a sufficiently large difference appears between each of those voltages and its respective reference, the controller connects the battery power source to the input of the boost circuit and simultaneously disconnects the primary power source therefrom. This switching of power sources is transparent to the load whose input voltage is maintained at a substantially constant level by the boost power factor correction circuit.

Abstract: A capacitor input type rectifier having a circuit for preventing an inrush current uses an AC phase detector for detecting the time that an AC voltage input has the smallest phase angle and provides an output signal indicative thereof to a phase control rectifier for initiating rectification of the AC voltage to provide a rectified output to a smoothing circuit for smoothing the rectified output of the phase control rectifier.

Abstract: In a control apparatus for controlling the firing timing of each of thyristor valves constituting a thryistor bridge by use of at least two series of control systems, a bypass-pair control circuit for thyristor bridge includes a circuit for detecting the conduction states of the thyristor valves, and a circuit for determining a conductive valve at the time of bypass-pair operation in accordance with a result of detection of the conduction state of each thyristor valve.

Abstract: An improved turbine engine igniter exciter circuit. An oscillator circuit drives the primary winding of a transformer for charging a capacitor to a predetermined voltage greater than the voltage required to sustain a spark discharge at an igniter but less than the voltage required to establish a spark discharge at the igniter. A timing circuit periodically triggers an SCR to discharge a portion of the energy stored in the capacitor through the primary winding of a step up transformer to create a short duration high voltage ignition pulse for establishing the spark discharge. The remaining lower voltage energy in the capacitor sustains the spark discharge for a predetermined time.

Abstract: A power supply for an X-ray tube having a feedback loop for regulating the high-voltage output signal of the power supply and allowing operation from AC lines of different voltage characteristics. The single-phase components of the input AC line voltage pass through separate silicon controlled rectifiers before being applied to a step-up transformer. The high-voltage transformer output is monitored by a shielded resistor divider and processed to produce a low-voltage control signal for controlling the input rectifiers.

Abstract: An AC/DC converter is provided, suitable for use in an advanced single phase, sine wave voltage, high frequency power distribution system, such as that used on a 20 kHz Space Station Primary Electrical Power Distribution System. The converter comprises a transformer, a resonant network, a current controler, a diode rectifier and an output filter. The voltage source is converted into a sinusoidal current source. The output of this current source is rectified by the diode rectifier and is controlled by the current controller. The controlled rectified current is then filtered by the output filter to obtain a constant voltage across the load.

Abstract: A power supply circuit for a high-frequency source (M) in a microwave oven includes a switched-mode-power-supply unit having a resonant circuit which contains a coil (L2) and a controllable switch (D1). The switching of the controllable switch is controlled by a control circuit (K) via a driving stage (S). The power supply circuit is cooled by a fan (F). The required DC voltages for supplying the driving stage, control circuit and fan are obtained by means of an auxiliary winding (W1, W2) on the coil (L2) and a rectifier (D3, D4). This results in a saving in both space and costs. At the same time, automatic supervision of the different functional units of the power supply circuit is obtained.

Abstract: The power factor correction circuit can deliver a high output power, high efficiency and high power factor. AC, e.g. line, voltage is converted into DC voltage. The high power and high efficiency are achieved by using diodes as only semiconductor devices conducting higher average currents. The correction circuit has an input and output. A rectifier network is coupled to the input for providing a pair of rectified signals. One rectified signal is applied to the output. A capacitor stores a DC voltage. A charging circuit selectively applies the other rectified signal to the capacitor. A diode applies the DC voltage to the output. A sinusoidal input current can be obtained. Inrush and surge currents are eliminated.

Abstract: A control circuit is provided for the output of a high frequency inverter of the type having an output transformer with a core, primary windings and a secondary winding with two sections for creating a first secondary current pulse of electrical current in one section when the primary windings magnetizes the core and a second secondary current pulse in the other of the secondary sections when the primary windings remagnetizes the core. By alternating switch means for passing current through the primaries to magnetize and remagnetize the core at a preselected rate the output current pulses are provided by the two sections of secondary windings. The control circuit of the present invention involves a modification of the output transformer secondary stage. A first auxiliary winding is connected to one of the secondary sections to create an auxiliary current pulse as the core of the transformer is magnetized.

Abstract: A regulated plasma display power supply includes sequencing circuitry for triggering the high voltage power supply output only after other computer operational voltages are properly functioning. The power supply output is disabled if any of those operational voltages fail. A power supply short circuit protection scheme is included to prevent high power dissipation in the power transistor and possible damage to the regulator. Over-shoot protection is provided at the power supply input to protect the power supply components from over voltage spikes.

Abstract: A power controller includes a full-wave bridge rectifier circuit coupled to an A.C. line by a storage inductor with two windings and a saturating inductor. The output of the bridge rectifier is connected to a D.C. output terminal for producing output voltages for a symmetrical amplifier. The D.C. potential provided by the full-wave rectifier is compared with a ramp signal having an external ramp set point related to the D.C. output potential relative to a reference potential to provide a trigger pulse for controlling the time the SCR is gated on. A balancing system selectively switches auxiliary resistances in and out to maintain a desired balance. Upon sensing a gross imbalance, the SCR is turned off. The power controlling apparatus includes isolation circuitry for creating an isolation barrier having a high frequency path and a low frequency path. The high frequency path includes a transformer having main primary and secondary windings.

Abstract: A power supply apparatus, in which the three phases of an alternating-current main are connected each through rectifier elements connected in antiparallel to the primary winding of a three-phase transformer. The secondary windings of this transformer are connected through rectifiers to a load device, such as an electron beam gun or other such device which produces short-circuits while in operation. Measuring sensors are provided on the primary AC side which, in the presence of an excess current on the primary AC side, block controlled rectifier elements. The blocking takes place very rapidly because GTO thyristors are used as rectifier elements. The decay of the magnetic energy in the transformer is achieved by the fact that the primary side of this transformer is connected in delta.

Abstract: The present invention relates to a power source apparatus for supplying a stabilized D.C. output to an inverter. In a D.C. power source apparatus for an inverter comprising a forward power conversion circuit receiving commercial A.C. power supply for outputting D.C. power such as a thyristor rectifying circuit and control circuit for controlling the D.C. output voltage of said forward power conversion circuit, the disclosed D.C. power source apparatus for an inverter is provided with feedforward control circuit detecting the D.C. input current to the inverter. The D.C. current input to the inverter or a current equivalent thereto is detected by the feedforward control circuit as a detection signal, and based on this detection signal, an A.C. component virtually in phase with the A.C. component input to the inverter is output from the forward power conversion circuit, and thereby, the D.C. voltage ripple to the inverter is decreased.

Abstract: A supply circuit for supplying a smoothed direct current to a load comprises a series FET element in series with the load resistance. The supply circuit is fed from the AC supply network via a rectifier 54 and a smoothing capacitor 52 causing a ripple voltage to be present on the input terminals 2-1 and 2-2. The direct voltage component of the input voltage is present across load resistance 60 and the alternating voltage component of the input voltage is present across transistor 10. In the case of known supply voltage circuits the voltage drop across the series element is selected to be equal to the maximum peak-to-peak value of the alternating voltage component thereby causing unnecessary power dissipation to be developed at a minor ripple amplitude. This will cause rapid ageing of the series element. The supply circuit in accordance with the invention comprises a comparator 42 comparing the voltage across FET transistor 10 to a threshold voltage.

Abstract: A high efficiency integrated power converter adapted for direct connection to line voltage and having on chip protection from overcurrent may be implemented utilizing a GTO-SCR as the switch element in a switching power converter such that the converter requires no external transformer or inductor based voltage reducing circuitry. The input voltage may vary over a wide dynamic range without deterioration in circuit performance due to the extremely high anode to cathode breakdown voltage of the switching element and further due to the on chip protection from excess current flow through the switching element.

Abstract: A start-up circuit for a switch mode power supply includes a transformer supplying a full wave rectifier and developing a reference potential from a zener diode connected at the output thereof. An SCR has its anode-cathode circuit connected between the rectifier output and the input terminal of the switch mode power supply and its gate coupled to the zener diode. The power supply applies a boot strap voltage, higher than the reference potential, to its input terminal which back biases the gate of the SCR. The transformer is, therefore, effectively disconnected from the switch mode power supply after start-up. The start-up circuit also can function as a voltage regulator in which the rectifiers conduct as needed during the AC voltage ripple peaks to maintain an output voltage determined by the reference potential.

Abstract: A constant voltage power supply employs a circuit in which the average voltage over a specified period of time is maintained constant by a circuit for charging a voltage storage means with width modulated pulses applied several times during each specified period whereby to charge the storage means above the desired average level and terminating charging until the voltage falls below the specified level. The period of time over which the voltage is averaged is a function of the thermal inertia of a load to be driven. The average voltage is employed as the energizing circuit to a high frequency oscillator, and driver stages supplying the output of the oscillator to an output stage of a power supply whereby the energizing voltage of the stages and thus the dissipation of energy therein does not exceed that required to feed the lead at its then current energy requirements.

Abstract: A transfection high-voltage controller for directing high-voltage currents to a suspension of cells and DNA comprising a control section, a power store, and a high-joule switch. Under control of the control section, the high-joule switch directs a high-voltage current from the power store to a load such as a cuvette. The high-joule switch comprises a semiconductor controlled rectifier (SCR) having a gate coupled to the control unit for triggering the device, an anode for receiving the high-voltage current from the power store, and a cathode for delivering the high-voltage current to the cuvette. A current sink may be connected to the anode of the SCR to render it non-conductive a predetermined time after the high-voltage current appears at the cathode. Multiple SCRs may be connected in series to support voltages over 3,000 and currents in excess of 125 amperes, and a trigger control unit may be attached to the gate of each SCR in the series to effect simultaneous or serial triggering of the group.

Abstract: An impulse high voltage generator includes a step-up transformer for stepping up a voltage from an AC power source, a thyristor connected with a primary winding of the transformer for controlling the AC voltage from the AC power source by a firing angle, a full-wave rectifier and a capacitor which are connected with a secondary winding of the transformer, and a discharging resistor connected through a high-speed switching element to the secondary winding. The thyristor is turned on at a firing angle in accordance with a frequency which is set by a setting device for setting an impulse high voltage occurence frequency so that the capacitor is charged, while when the thyristor is turned off, the high-speed switching element is turned on to discharge the capacitor so that an impulse high voltage is generated across the discharging resistor. The impulse high voltage generator can vary a peak value and the occurrence frequency of the impulse high voltage simply and inexpensively with high efficiency.

Abstract: Prior types of power conversion circuits for converting AC power into DC power have generated large amounts of undesirable electromagnetic interference (EMI) due to the rectification of the AC power. Such EMI has been reduced in the past by large and heavy filters which have undesirably increased the size and weight of such conversion circuits. In order to overcome this problem, a harmonic reduction circuit according to the present invention includes a current sensor for sensing the current in the AC lines, circuitry for developing a pulse width modulated (PWM) waveform having a duty cycle dependent upon the sensed AC line current and a switching circuit coupled to the AC power line and controlled by the PWM waveform developing circuitry for compensating the AC line current whereby undesired harmonics therein are reduced.

Abstract: An electronic power supply that converts alternating current to a regulated DC voltage with high efficiency is accomplished by a switch that connects the input AC power source directly to the DC output filter capacitor. This occurs when the input voltage equals the output voltage, and the output voltage is less than the set value.This power supply can be used with low impedance AC power sources capable of providing high surge currents such as commercial utility lines.

Abstract: Method and arrangement for varying a d.c. voltage occurring between electrodes of an electrostatic dust separator, said voltage being generated by a number of frequency-related pulses together forming a pulse train. A mains voltage (50 Hz) is fed via valve organs (8, 8a) controlled by a control circuit (7) to a transformer (T), the current pulses of which are full-wave rectified (9) and are connected to electrodes (10) of the dust separator. The control circuit (7) is so arranged as to extinguish an even number, being two, four or more, of pulses from the mains voltage between two consecutive pulses supplied to the electrodes of the dust separator.

Abstract: A line-frequency switching power supply for producing a regulated D.C. output voltage includes a pass element disposed between a rectifier circuit and an output terminal to which a filter is connected. The pass element is enabled when a zero-crossing of line voltage is detected, and switched on when the line voltage exceeds the voltage on the filter capacitor plus the operational drop across the pass element. The pass element is switched off when the output reaches a preselected D.C. output level, tripping a switch. Since the pass element is switched on for only a portion of a cycle of line voltage, power dissipation is minimized and efficiency is kept high. Regulators of type described herein suitably may be stacked on a single secondary winding to produce multiple output voltages, or may suitably function as preregulators for following linear regulators to produce very stable and constant D.C. output voltages with minimum power dissipation.

Abstract: An improved switching arrangement for a direct coupled switching power supply is provided by utilizing a gate turn off SCR as the primary switching element and a second SCR as the turn-off control such that upon detection of any of a fully charged storage element, an excessive current through the gate turn off SCR, or an insufficient input voltage, the switch is turned off.

Abstract: A novel high-voltage pulse power source comprising an ON-OFF type high-voltage switch element, as high-voltage switch element, which can be reset in OFF state immediately after an ON action, and a current blocking mechanism arranged in the charging power source, whereby an output current from the charging source is inhibited by said current blocking mechanism to stop charging and generating of any dynamic current flow into the load during period of time from an ON action of said ON-OFF type high-voltage switch element till an OFF action of the same, and the flow of said output current is restored during an OFF state of said ON-OFF type high-voltage switch element after an OFF action of the same. In addition, a novel pulse-charging type electric dust collecting apparatus equipped with said novel high-voltage pulse power source.

Abstract: A regulated power supply that provides two desired direct current voltages at respective outputs thereof, the supply maintaining the difference between voltages appearing at the outputs the same as the difference between the desired values, series regulators respectively coupled to each output that are in a saturation mode when a voltage that is a fraction of the voltage between the outputs lies within a given range, where one of the series regulators is placed in a linear mode when the voltage is at or beyond one edge of the range, and the other series regulators is placed in a linear mode when the voltage is at or beyond the other end of the range.

Abstract: A high-frequency high-voltage power supply in which a high-frequency high-voltage is generated with the aid of L-C oscillation without a high-frequency primary power supply or a high-frequency high-voltage converter. The negative output terminal of a first D.C. high-voltage power supply and the positive output terminal of a second D.C. high-voltage power supply are connected together and to one of the high-frequency high-voltage output terminals. Tank capacitors are connected between the positive and negative output terminals of the power supplies, respectively. One end of a first combination of a first thyristor and a first rectifier connected in anti-parallel relationship is connected to the positive output terminal of the first power supply with the anode of the first thyristor connected to the positive output terminal.

Abstract: A power supply circuit for driving a motor includes a rectifier circuit and a converter circuit for stepping down the DC voltage from the rectifier circuit to drive a motor. The power supply circuit further includes a regulator circuit which is energized by the DC output voltage from the converter circuit to supply a constant voltage or current to the motor.

Abstract: The invention relates to apparatus for supplying an electric consumer with a high DC voltage which includes provisions for minimizing the danger and hazard of electrical shocks associated therewith. The apparatus includes a power circuit and a measuring control circuit which are separated by high ohmic resistors and an optocoupler.

Abstract: A power supply device includes a plurality of switching regulators and a waveshaping circuit, or, a switching circuit for converting an input voltage to switching pulses, a transformer for transforming the voltage of the pulses generated in the switching circuit, a rectifier circuit for rectifying the switching pulses provided through the transformer, a switching regulator into which the resulting d.c. input is supplied from the rectifier circuit and a waveshaping circuit. The former waveshaping circuit shapes the waveform of switching pulses generated within one switching regulator of the plurality of switching regulators and supplies the shaped output to the other switching regulators as an input reference waveform. The latter waveshaping circuit shapes the waveform of the switching pulses provided from the transformer and supplies the resulting function waveform to a pulse control unit in the switching regulator as an input reference waveform.

Abstract: The method of supplying voltage to an electrostatic precipitator, includes periodically reversing the polarity of a supply voltage; intermittently supplying voltage to the precipitator; and the supply voltage polarity being reversed during no-voltage intervals, with the reversing of polarity being delayed with respect to the beginning of the no-voltage interval.

Abstract: Spikes occurring on an AC line and coupled through an AC to DC converter are substantially decoupled from a DC load of the converter even though the converter includes a supply transformer and a shunt electrolytic filter capacitor, by a circuit comprising a shunt network including a bidirectional breakdown means having a predetermined threshold conduction level with a dead band series connected with a capacitor. The capacitor is a low impedance capacitive reactance to high frequency components in pulses developed by the converter in response to the spikes, and a high impedance to ripple of the line derived by the converter. The high frequency components are supplied by the breakdown means to and through the capacitor to momentarily interrupt the flow of current from the converter to the load when the pulses are derived. A low pass filter connected in series with the shunt network and the load has a cut-off frequency lower than the ripple frequency.

Abstract: Disclosed is an electrical power system adapted to receiving power from a source of alternating current, typically a small alternator, and supplying a direct current potential to a load. This power system includes two stages, the first stage comprising switchable rectifying devices such as silicon controlled rectifiers which interact with the impedance of the alternator or other source of alternating current power as a switching regulator to create an intermediate direct current potential.The second stage operates from this intermediate direct current potential to produce a slightly lower output voltage, and creates a more accurate regulation than is possible with the first stage alone, the second stage greatly reduces ripple and high frequency noise components contained on the output of the first regulator stage. The second stage serves as an active low pass filter tuned to a desired DC voltage.

Abstract: A power supply for a highly inductive load comprises a variable DC source, a unidirectional controlled switching device coupled to the DC source, an inductance in series between the controlled switching device and the load and a capacitance shunting the load. The controlled switching device has a gate coupled to receive a voltage signal functionally related to that across the load so that the controlled switching device will be turned on at the frequency of oscillation of the voltage across the load to provide current pulses to the load.

Abstract: The high voltage field effect transistor has a drive circuit for pulse width modulation, which includes a small transformer coupled to the gate and source with a diode in series at the gate, so that a very short on-drive pulse charges the gate capacitance, and the charge is held by the diode. Another FET has its output connected between the gate and source of the high voltage FET, and its input coupled to another small transformer so that it is turned on for a short time by a very short off-drive pulse to discharge the gate capacitance and thus turn off the high voltage FET. A transformer drive circuit includes two one-shot devices connected to the pulse width modulator as leading and trailing edge detectors respectively, with their outputs connected via FET's to the on-drive and off-drive transformer primaries respectively, to provide pulses of 100-200 nanoseconds.

Abstract: A novel converter circuit converts AC input voltage within the range of 85-260 VAC to a constant voltage, current limited DC output voltage wth substantially no input voltage, all without the use of a transformer or input voltage-select switch. The AC input voltage is inputted directly to a rectifier and then to the input of a phase-controlling element (SCR) for controlling the phase of the unfiltered rectified signal. A trigger signal-generating circuit generates a trigger signal for regulating the operation of the phase-controlling element. A ripple-removing filter circuit receives the output from the phase-controlling element and removes the ripple component. A voltage-regulating circuit, a current-limiting circuit, and a rapid start-up circuit to facilitate rapid generation of DC output signal soon after energization of the overall circuit by an AC power source are also disclosed.

Abstract: In an electric dust collecting apparatus of the type that a dust collecting effect is achieved by applying a high D.C. voltage between dust collecting electrodes, wherein the high voltage is controlled via a typical power control device including thyristors, there is provided an additional control circuit for intermittently controlling the power control device to generate an intermittent high voltage output in such a manner that both the repetition rate and the pulse width of the D.C. high voltage output may be adjusted either manually or automatically so as to improve the dust collecting efficiency of the apparatus and to reduce the power consumption thereof.

Abstract: A power supply for repetitive discharge apparatus such as a laser comprises an unregulated DC source, a primary storage capacitor, a discharge capacitor forming part of the apparatus and an energy feedback circuit between the discharge and storage capacitors operative to return to the storage capacitor energy greater than that required for a predetermined charge level on the discharge capacitor. A switch responsive to the voltage on the discharge capacitor operates a divert excess charging current into resonant charging elements in the feedback circuit for return to the primary storage capacitor. Transfer of the excess charging energy is accomplished nondissipatively to provide highly efficient cycle by cycle voltage regulation.