Abstract: An X-ray generator system has first and second switching devices such as transistors which are complementarily turned on and off to intermittently apply a DC voltage to the primary winding of a transformer for thereby inducing a high voltage across secondary windings of the transformer for enabling an X-ray tube to emit X-rays. The X-ray generator has a control mode in which the first and second switching devices are simultaneously turned on immediately before they start being complementarily turned on and off, for allowing the high voltage to have a sharply rising positive-going edge.

Abstract: Uninterruptible power supply apparatus which provides for supplying ac power to equipment even if and when the primary ac power is interrupted is disclosed and comprises an ac to dc converter connected to receive the primary ac power. The output of the ac to dc converter is applied to a dc power source. The resultant output of the ac to dc converter and the dc power source is provided as a dc input to a dc to ac inverter. The dc to ac inverter comprises an output transformer having a center-tapped primary. A first switching device is connected between a first end of the center-tapped primary and the negative terminal of the dc input to provide power pulses to one-half of the center-tapped primary. A second switching device is connected between a second end of the center-tapped primary and the negative terminal of the dc input to provide power pulses to the remaining half of the center-tapped primary.

Abstract: A switched-mode power supply having a main output (O/P1) and one or more other outputs (O/P2, O/P3 and O/P4), wherein the outputs are regulated both by flyback control and forward control and wherein the power supply includes a transformer (T) having a primary winding, a main output winding (L2) and one or more other output windings (L3, L4 and L5), a primary converter (1) associated with the primary winding, a forward conversion circuit (S1, T, D2, D3, L.sub.

Abstract: Disclosed is an inverter type X-ray apparatus comprising a DC-DC converter for converting a DC voltage into a different DC voltage, an inverter for inverting an output voltage of the DC-DC converter into an AC voltage, a high voltage transformer for transforming an output voltage of the inverter into a higher voltage, a rectifier for converting an AC output voltage of the transformer into a DC voltage, and an X-ray tube to which an output voltage of the rectifier is applied. In the apparatus, the DC-DC converter includes a reactor, a switching element and a capacitor which are interconnected so that the DC-DC converter can generate an output voltage higher or lower than an input voltage.

Abstract: The present invention describes a charging circuit for energy storage capacitors which is especially useful in charging the energy storage capacitors used to provide the voltage supply of flashlamps in photocopying machines. The charging circuit has two series-connected d.c. converters and a current limiting device. The current limiting device has a measuring circuit for determining the current through the second d.c. converter, which is related to the output current of the first converter, and a regulating circuit for regulating the output current of the first d.c. converter and thus indirectly regulating the output current of the second d.c. converter.

Abstract: Each of a plurality of parallel connected power supplies is controlled by a parallel control circuit which measures the output current from each power supply and compares this output current to the average output current produced by all the power supplies and generates a signal representative of the difference therebetween to drive the output current of the power supply toward the average output curent from all power supplies. The structure includes in addition a switch for disconnecting the parallel control circuit of a failed power supply from the system and a booster resistor for assisting in bootstrapping the startup of a given power supply being inserted into parallel with the preexisting parallel connected power supplies.

Abstract: The circuit includes an inverter to be connected to a source of d.c. power. The inverter has a transformer with a center-tapped primary winding. Separate controllable switching devices are connected to the respective ends of the primary winding. Both switching devices are arranged to be connected in common to one output terminal of the d.c. power source. The center tap of the transformer primary winding is arranged for connection to the other output terminal of the d.c. power source. The transformer has a laminated silicon steel core, and includes a secondary winding arranged for connection across the input terminals of a gaseous discharge lamp. A control circuit is connected to control conduction by the separate controllable switching devices in alternating sequence at a desired frequency of operation.

Abstract: A switch mode power supply comprises an oscillator arranged to drive the primary winding of a transformer. A nuclear impulse detector is arranged to discontinue drive to the primary winding in response to detection of a nuclear impulse.

Abstract: A low power high efficiency switching power supply comprises a switching transducer having primary and secondary windings. The primary winding is supplied with a primary voltage over a series connected constant current source and Zener diode. The primary voltage is chopped by an FET which has a gate connected to an oscillator operating at relatively low frequency. The secondary windings of the transformer are connected to full-wave rectifiers which convert the A.C. signal produced by the chopping of the primary voltage, int a D.C. signal. Efficiency is maximized by using fast switching FET's and low flux densities in the transformer. The power supply is particularly useful in 4-20 mA current loops.

Abstract: Subject invention constitutes a low-voltage limited-power (Class 2) fluorescent lighting system consisting of the following principal component parts: (a) a power-line-operated inverter power supply that provides a power-line-isolated voltage output of relatively low but substantially constant magnitude (30 Volt RMS) and relatively high frequency (30 kHz); (b) electronic means for preventing the power supply current output from exceeding a pre-determined relatively modest magnitude (8 Amp RMS); (c) a number of fluorescent lighting units, each unit consisting of one or more fluorescent lamps and a corresponding high-frequency ballasting means being adapted to be operated at a high power factor from the voltage output of said power supply; and (d) a pair of conductor wires connected with the output of said power supply and adapted to permit a number of said fluorescent lighting units to be connected in parallel across said voltage output at various points along said pair of wires.

Abstract: The voltage present at an input is chopped by a switch which is actuated by a pulse-width modulator controlled by the output voltage and is smoothed at least by a low-pass filter, consisting of an inductance and a capacitance, at the output. In order to reduce to a minimum the delay between the time an input voltage is applied and the time a rated value is at least approximately reached by the output voltage, the inductance is bypassed by a bypassing circuit which has a low inductance and which conducts if the output voltage is below a minimum voltage and in other cases is turned off. It contains, for example, a switch which is constructed as a switchable current source and which is actuated by a comparator comparing the output voltage with a reference voltage. In transformer-coupled embodiments, isolation between the output and the input is possible. The supply unit is suited, for example for supplying auxiliary devices of an instrument transformer from the current of the power-line to be monitored.

Abstract: Each of a plurality of parallel connected power supplies is controlled by a parallel control circuit which measures the output current from each power supply and compares this output current to the average output current produced by all the power supplies and generates a signal representative of the difference therebetween to drive the output current of the power supply toward the average output current from all power supplies. The structure includes in addition a switch for disconnecting the parallel control circuit of a failed power supply from the system and a booster resistor for assisting in bootstrapping the startup of a given power supply being inserted into parallel with the preexisting parallel connected power supplies.

Abstract: A method and apparatus for controlling a power supply which includes a power transformer having primary and secondary windings and switching transistors for switching current through the windings. The apparatus includes circuitry for generating a composite signal representative of the flux and magnetizing current (I.sub.m) in the power transformer. The composite signal is correlated with a multiphase clocking signal to generate a pulsewidth modulated (PWM) signal which is used to drive the switching transistors.

Abstract: A resonant dc-dc converter employing power transistors as the switching elements generates a high dc output voltage (150 kilovolts) to drive an X-ray tube. The converter is configured such that the resonating circuit elements can be realized using the transformer parasitic elements. Voltage step up is achieved due to the transformer turns ratio as well as the resonant rise of voltage across the energy storage elements of a series resonant circuit.

Abstract: This disclosure relates to a system for supplying a stable DC high voltage to a load by resonantly driving a high voltage transforming circuit comprising a VLT and a capacitor type multiple boosting circuit. The system includes a VLT, a capacitor type multiple boosting circuit and a pulse-amplitude feedback control circuit designed to detect supply voltage to load, to compare the detected voltage with reference voltage and to control the voltage of the control winding of VLT by using the deviation produced by the comparison as a control signal.

Abstract: The object of the invention is to provide an improved converter for converting one direct current voltage to another.A plurality of phased square wave voltages are provided from a ring counter (14) through amplifiers (A.sub.O1 -A.sub.O6) to a like plurality of output transformers (TO). Each of these transformers has two windings, and S.sup.1 winding and an S.sup.2 winding. The S.sup.1 windings are connected in series, then the S.sup.2 windings are connected in series, and finally, the two sets of windings are connected in series. One of six SCRs (SCRs 1-6) is connected between each two series connected windings to a positive output terminal (22) and one of diodes (D1-D6) is connected between each set of two windings of a zero output terminal (0). By virtue of this configuration, a quite high average direct current voltage is obtained, which varies between full voltage and two-thirds full voltage rather than from full voltage to zero.

Abstract: A power supply for an electric insect trap having an electrocution grid and a fluorescent lamp for attracting insects to the grid employs an inverter to generate a high frequency alternating voltage. The alternating voltage is applied across the primary winding of a first transformer having a secondary winding for development of a current-limited voltage for operating the lamp. Due to large inductance, the secondary winding functions as a constant current source to the lamp, so that lamps having different voltage characteristics may be used in the same circuit. A high voltage transformer has a primary driven by the limited lamp current to produce a high voltage for the electrocution grid across its secondary winding. Current limiting is achieved, in part, by providing a selected amount of flux leakage between the primary and secondary windings of the first transformer.

Abstract: DC-to-dc switching converters that deliver non-pulsating output current use a conventional transformer and a flyback transformer with primary windings recurrently connected in series to the primary d-c energy source and with secondary windings alternately connected to the output load.

Abstract: A system is provided for driving the switching transistors in a push-pull switching mode inverter-type power supply. The system of the invention provides drive current adjusted to the actual power supply load throughout the entire switching cycle from turn-on to the completion of turn-off for each of the switching transistors. There is essentially zero power dissipation in the various elements which make up the system. Moreover, the system obtains substantially all of its drive power from the outputs of the switching transistors themselves, and it provides transformer isolation for the switching transistors.

Abstract: An inverter circuit is disclosed in which the alternating current output is rectified to become a DC power supply with a regulated output voltage. The inverter is controlled to limit the peak current conducted by the power semiconductors and a current limit circuit is provided to limit the DC output current. The invention provides an output current sensing circuit utilizing a current transformer, with the primary winding thereof connected in the alternating current portion of the inverter circuit and with current flow in the primary winding proportional to the DC output. Rectifier means is provided to rectify the output of the secondary winding of the current transformer, and this is supplied across a first resistor. There is means to sample the voltage across this first resistor only during the conduction period of the power semiconductors. An integrating means is provided to integrate the sampled voltage and develop an output current signal for control of the output current from the inverter circuit.

Abstract: A d-c converter for inclusion in a miniature electronic device, such as an electronic wristwatch having a d-c supply source, the converter functioning to increase or decrease the voltage of this source. The converter includes a transformer whose primary is connected to the source through a periodically-actuated chopper to produce an alternating voltage, the secondary of the transformer being connected to a rectifier circuit having at least one controllable switch element whose on-off state is governed in synchronism with the chopper whereby the switch element acts to rectify the secondary voltage.

Abstract: A Royer circuit, which includes an inverter and a saturating output transformer, is powered from a current source rather than from a voltage source, thereby reducing transistor current overshoot when the output transformer saturates. A current source inductor and a PWM (pulse width modulated) power transistor are series connected in the current return line of the inverter. The PWM power transistor emitter is connected so that potential between it and the common DC input power terminal will be low. This permits the PWM power transistor to be direct-coupled from a low voltage PWM switched mode power supply control circuit. A start-up circuit for supplying start-up power to inverter control circuitry from the DC input source is provided. Feedback loop control for the PWM power transistor is also provided.

Abstract: A separately-excited DC-DC converter having a feed-back loop for providing stable operation notwithstanding changes of load. The feed-back loop may include a temperature-responsive element so as to provide stable operation even under changes of the ambient temperature.

Abstract: A power supply which serves as a power converter from a relatively low primary direct current energy source, to a generally higher value of secondary direct current power for application to an electric load element. The secondary power is voltage regulated. Regulation is provided by limiting the number of electric pulses of primary power produced by the converter to not more than the least total number of such pulses necessary to maintain the secondary voltage at its preferred average d.c. voltage level.

Abstract: An uninterruptible power supply utilizes a controlled ferroresonant regulator to derive a regulated DC voltage from a primary AC source. A reserve source of DC power is coupled to the output through a DC voltage regulator which is activated when the DC output voltage of the power supply drops below a predetermined threshold.

Abstract: A novel feedback circuit for use in a DC-to-DC converter accurately adjusts the pulse width of the control pulses to a pair of switching transistors to minimize current imbalance. The switching transistors generate current pulses in the primary windings of a center tapped transformer. The feedback path senses the current pulses in the primary circuit of the transformer. A filter in the feedback path has a bandwidth centered at about the frequency of any current imbalance. The high gain, closed loop feedback path changes the slope of alternate linear ramp voltage pulses, and hence varies the pulse width of the pulses presented to the control terminals of the switching transistors.

Abstract: Voltage converter apparatus is disclosed having circuitry for regulating the output voltage to maintain it at a regulated value. Use is made of switching devices that switch between their alternative states in a cyclic manner and at a particular frequency which is determined by the circuit constants. An inductance is provided for modifying the waveform of the current fed to the output transformer, so that at certain periods of the cycle there is a lesser contribution to the integrated output--i.e., the output is not a true 1:1 square wave. Then, by changing the switching intervals, the integrated output can be controlled. A current transformer is provided for sensing current changes occurring in the output transformer, and a short circuit arrangement is provided for short circuiting a control winding of the converting transformer to control the instants of switching of the switching devices.

Abstract: An intrinsically safe regulated power supply has an input connected to a source of power and an output connected to a voltage-limited diode. The output current is limited by having a current sensor placed in series between the output terminal of the regulator and the diode. The current sensor generates an output which is applied to a differential amplifier. The differential amplifier develops an output voltage which is proportional to the current passing through the current-sensing means. This voltage is converted to a corresponding frequency which forms pulses having a repetition rate proportional to the frequency from the voltage-to-frequency converter but having a constant width. Pulses are applied to output transistors which control the current through the primary of a transformer. An excessive output current will convert the pulses to a low repetition rate, drastically cutting the voltage which will prevent excessive current through the load.

Abstract: A regulated DC to DC power supply of reduced complexity which delivers increased power to the load. The improved circuitry substitutes an inductor for the usual inductor-capacitor-switching transistor arrangements, and drives the inverter circuitry so that the on-times of opposite inverter transistors overlap.

Abstract: This circuit converts a DC voltage of one value to a regulated DC voltage of another value. The circuitry includes a variable frequency clock controlled by an error voltage derived from the converter output. A pulse of constant length is produced for each cycle of the clock. Logic circuitry is arranged to alternately feed these constant length pulses to opposite sides of a push-pull power amplifier, the output of which is rectified and filtered to form the converter output.

Abstract: A power control circuit which includes at least one DC power source; and at least one transformer including an excitation winding, a primary winding and a secondary winding; at least two transistors; and at least two diodes. In this circuit, a current increasing with time is caused to flow through the primary winding after energy has been accumulated in the excitation winding. Furthermore, a current induced in the secondary winding by the current of the primary winding and a current resulting from the energy of the excitation winding are superimposed upon each other, and the current resulting from such superimposition is rectified so that there is provided a continuous output.

Abstract: A switching regulator capable of performing open-loop functions. The inhet nature of the circuit provides a constant power translation regulator with short circuit dropout protection. Normal voltage or current regulation may be obtained by utilizing a control winding provided for that purpose. A free-running or locked blocking oscillator circuit in combination with a pulse width controlled switching regulator sustains its own drive and regulation functions. Measured efficiencies from 90 to 99 percent are obtainable with both resistive and line modulator type loads.

Abstract: A power supply of the switching type having alternately conductive switching transistors coupled to the primary of a transformer, in which a control circuit insures that the switching transistors are never simultaneously conductive. The control circuit utilizes two multivibrators having a common timing circuit for generating pulses which have their leading edges synchronized and are such that the width of the pulses from one multivibrator is never less than the width of the pulses from the other multivibrator, thus insuring a minimum dead time interval between the on times of the alternately switched transistors. Circuit protection is provided by sensing and feedback of the current through the transformer secondary or primary windings, and by sensing the saturation voltage across the switching transistors, to regulate the duty cycle of the pulses generated by the control circuit. Power for the control circuit and the switching transistor drive circuitry is provided from the secondary of the transformer.

Abstract: A DC-DC converter includes a switching transistor coupled to output terminals via an inductor and a rectifier. The converter also includes a circuit for sensing whether a current change in the main current path of the switching transistor reaches a given value subsequent to an initial current rise, if any, at the start of a conduction period. A control circuit is responsive to said sensing circuit to remove the drive to the switching transistor if said given value is reached.

Abstract: In a DC to DC converter, an improvement for reducing the peak current level through the electronic charging switches including an inductance in series between the junction of the clamping diodes and the junction between the primary side of the transformer and the primary capacitor.

Abstract: In a switched mode power supply of the push-pull type the drive to each output transistor is terminated just after its collector current reaches the value which the collector current of the other transistor had when the drive thereto was removed in the immediately preceding conduction period, in order to substantially equalize the drive to the output transformer contributed by each output transistor. This is done by means of sampling and storage circuits which store signals representative of the values of the collector currents in the two output transistors which occur when their drive is removed in combination with a comparison circuit which compares each stored value with the collector current of that transistor which conducts during the next conduction period.

Abstract: Power supply having means for developing a voltage overload signal representing a current overload condition in the power supply and then reducing the output current from the power supply as a result of the voltage overload signal. The voltage overload signal is applied to a servo or error amplifier to cause the error signal therefrom to change in a manner to reduce the power supply output voltage which in turn is fedback to the said amplifier to cause output current foldback.

Abstract: A circuit for the production of an output voltage generated based upon an input direct voltage and a given desired voltage. A series connection comprises a longitudinal regulating member, an inductor and a push-pull current transformer which produces the output voltage. The input direct voltage is fed to the push-pull current transformer. The push-pull current transformer includes a push-pull transformer having push-pull primary winding and a secondary winding. In addition, the push-pull current transformer includes switching transistors which are switched on and off in push-pull by a control circuit. The control circuit delivers a suitable cyclical changing control signal to the switching transistors. Circuitry is provided for minimizing if not eliminating spikes in the current occurring during a switching of the switching transistors. As a result, the switching transistors remain free from excessive voltages which can damage same.

Abstract: A high frequency inverter power supply includes a high power inverter section powered by substantially unfiltered rectified a.c., and a control section including rectifier and filter means for providing substantially pure d.c. to maintain continuous instantaneous control over the high power inverter section. High frequency transformer means and optional output rectifiers and filters provide for a.c. or d.c. output.

Abstract: A regulated power supply which may be of the A.C.-to-D.C. type utilizes a ries arrangement of inverters because of a voltage rating of these inverters with respect to the magnitude of the D.C. driving voltage available either as a consequence of rectifying an A.C. voltage source or other reasons. The regulator has a self-balancing feature which insures that all of the inverters equally share the D.C. driving voltage and also includes a protection feature which safeguards the inverters against damage caused by a malfunction of any one of the units.

Abstract: A single-ended converter circuit operating in a transformer coupled mode is disclosed having multiple outputs. A current limiting circuit is included on the primary side of the power transformer to limit the total aggregate current output of the converter. Secondary current limiting circuitry is included in selected ones of the multiple outputs to individually limit current outputs of the converter. A similar current limiting arrangement is disclosed for application to double-ended type converter circuits.

Abstract: A power supply provides a low-level DC voltage to DC load circuits by first rectifying the standard AC voltage and thereafter reducing the rectified AC voltage to the low-level DC voltage. The reduction of the rectified AC voltage to the low-level DC voltage is accomplished by a power transformer which is switched on or off by a pair of switching transistors. The switching transistors are operated in a "push-pull" mode by a pair of control transformers operating in combination with a control circuit. The control circuit produces various pulse conditions in the control transformers which turn their respective switching transistors on and off in a prescribed manner.

Abstract: A magnetically coupled two transistor multivibrator for use with power supplies. In addition to the usual collector driven output transformer, an auxiliary transformer having its secondary winding in series with the transistor base drive circuits is employed. The auxiliary transformer has primary windings powered by emitter current. Provision is also made for feedback from the main output transformer so that the secondary base drive windings can be powered from either emitter or collector currents. Electronic means are employed to isolate the output transformer from the base drive transformer upon the occurrence of a short circuit in the load, thus permitting the emitter windings to take over the function of supplying feedback and maintaining oscillations.

Abstract: An inverter for direct current power generation is shown in which both voltage regulation and logical control of the output are achieved by digitally controlling the application of clock signals to the inverter circuit. A standard clock source is used to drive the inverter and digital circuitry, timed from the same clock source, is used to control the gating of clock pulses to the inverter. Entire clock pulses including both positive going and negative going transitions are blocked so as to preserve the balanced excitation of the inverter transformer. Logical control signals can also be used to disable the application of clock pulses.

Abstract: This disclosure relates to a converter-regulator circuit which has high immunity to transient voltages and which employs a feedback controlled operational amplifier at the input end for controlling the conductive condition of an intermediate transistorized inverter which supplies feedback signals from the output end of a bridge rectifier to provide a regulated d.c. output voltage.

Abstract: Disclosed is a multiple output DC-to-DC converter. The DC input power is filtered and passed through a chopper preregulator. The chopper output is then passed through a current source inverter controlled by a squarewave generator. The resultant AC is passed through the primary winding of a transformer, with high voltages induced in a plurality of secondary windings. The high voltage secondary outputs are each solid-state rectified for passage to individual output loads. Multiple feedback loops control the operation of the chopper preregulator, one being responsive to the current through the primary winding and another responsive to the DC voltage level at a selected output.

Abstract: A regulated power supply system, for a sensitive computer environment, having a plurality of switching regulators to provide highly regulated D.C. voltage to individual loads connected to each of the regulators. A centralized oscillator is used to supply the clock signal to the control circuit of each of the different switching regulators. Thus, any radio frequency interference problems will be associated with only one fundamental frequency and its related harmonics. A modified ring counter is used to stagger the turn-on point of each individual regulator so that the power demands on the source of power are not suddenly severe and instantaneous, which might generate transients disruptive of computer operations. Further, the modified ring counter is used to synchronize the frequency of each regulator to a common clock, in addition to its controlling the phase shifting of each regulator for a staggered turn-on.

Abstract: A power supply employing a clock-driven D.C.-A.C.-D.C. converter having a current transformer in the A.C. section to develop a trapezoidal current feedback pulse train which is then converted to a trapezoidal voltage pulse train. A comparator compares the trapezoidal voltage pulse train to a voltage reference level set such that it is normally crossed by the ramp portion of each trapezoidal voltage pulse. Upon occurrence of a ramp crossing, which varies with the level of the output current, a control pulse is produced by the comparator and supplied to gating logic which develops driving pulse trains for the D.C.-A.C.-D.C. converter and cuts off each driving pulse upon occurrence of a control pulse. The resulting power supply constitutes a voltage-controlled constant current power supply which may be connected with an arbitrary number of other such supplies to a power bus and to a common feedback-controlled voltage reference source.