Abstract: A flyback converter high voltage power supply which includes two switches operating in push pull fashion to provide alternate polarity energy pulses to a load. A main component of the power supply is a transformer, the primary winding of which is divided into halves. The secondary may be also be split into halves, or may be configured without a split so long as the secondary and rectifier combination result in full wave rectification. The first of the two switches couples an input voltage across the first primary half to store energy in the magnetic core during a first time interval, and at the end of the first time interval disconnects the first primary half from the input voltage. During a second time interval, the energy stored in the magnetic core during the first time interval is delivered to the load via the secondary winding.

Abstract: A magnetic sensor for measuring the helix current of a traveling wave tube (TWT). The sensor includes a helix current sense inductor and a reference inductor. The sense inductor includes windings for receiving the cathode and collector currents of the TWT and for receiving a bias current, and also a sense winding. The cathode and collector currents cause permeability of the core to vary in proportion to the difference between those currents, which is equal to the helix current. The bias current is supplied to the bias winding to compensate the sense inductor for temperature-related permeability variations. The bias current is supplied by the reference inductor which is selected to have magnetic properties which match those of the sense inductor. A plurality of sense inductors in conjunction with one common reference inductor may be used for sensing the respective helix currents in the TWTs in a multi-TWT array.

Abstract: A DC-AC converter circuit for a power supply contains a parallel resonant circuit topology. Accordingly, stray capacitance associated with the converter forms a part of the resonant circuit and assists in setting the resonant frequency thereof. The energy in the stray capacitance which is normally lost is recovered by the resonant circuitry. A coupled inductor is connected in series with a primary winding of an output transformer of the converter. The coupled inductor includes a resonating inductor winding and an energy recovery winding which are tightly wound out of phase with one another. Energy from the resonant inductor winding is coupled to the recovery winding when the switching elements of the converter are switched on and off. Therefore, energy otherwise dissipated in switching operation is conserved by being returned to its source. Further, the switching elements of the converter are connected in series through diodes to the return line.

Abstract: A metal base plate has two spaced thermally conductive ceramic bars fixed to one surface. The outwardly facing surface of the bars has spaced conductive pads. A plurality of diodes which are of alternating opposite polarity have axially extending leads extending between the bars in spaced parallel relationship with respect to one another, and are soldered to the conductive pads on the bars to define a series connection of the diodes. The suspended diodes and their leads are then encapsulated in a body of polymerizable material containing thermally conductive electrically insulative particles suspended therein such that the particles occupy more than about 75% of the encapsulating mass.

Abstract: A resonant current-driven power source is disclosed. Preferably, the power source is a DC to DC converter regulator including a inductor and capacitor electrically coupled to one another and an input inverter which converts an input DC voltage into an AC voltage having substantially no DC component and applies the AC voltage across an LC circuit in a manner which causes the inductor and capacitor of the latter to resonate with one another whereby an AC voltage appears across the capacitor. An output circuit converts the AC voltage appearing across the capacitor into a DC output voltage. A control circuit is provided for controlling the operation of the inverter circuit in a manner which controls the magnitude of the output voltage. The inverter circuit also includes a step-up transformer for increasing the magnitude of the AC voltage across the LC circuit to a value many times greater than the input DC voltage.

Abstract: A ripple and noise filter for high voltage DC converters or power supplies. The filter includes a common terminal, an input terminal and an output terminal. A voltage sensing circuit is connected between the output and common terminals of the filter and is adapted to produce a sense signal which is proportional to the output voltage at the output terminal. An active filtering circuit, preferably an amplifier having a frequency operating range which covers the frequency spectrum of the ripple and noise voltages, includes an input for receiving the sense signal and an output at which a correction signal is generated. The correction signal has a magnitude and waveform such that coupling the correction signal onto the output terminal of the filter eliminates or reduces the ripple and noise. A passive coupling element, preferably a capacitor, isolates the amplifier from the output terminal and couples the correction signal thereto.

Abstract: The inverter includes a DC to AC converter circuit including a plurality of transistors which are switched on and off to convert a DC signal into an AC signal. The converter circuit also includes diodes which are alternately forward and reverse biased during the operation of the converter circuit, the diode having a reverse recovery period whenever the diode is switched from a forward to a reverse biased condition during which the reverse resistance of the diode is substantially zero. An inductor is connected to the diode for limiting the current through the diode during the reverse recovery period such that shoot through currents which pass through both the diode and the inductor are limited to desired levels.

Abstract: A d-c to d-c forward converter power supply has a magnetic modulator in the timing circuit which operates between its residual magnetic flux density and its saturation flux density to deliver a fixed number of volt seconds during sequential clock interval periods. The clock period is fixed so that the output voltage averaged over each clock period will be constant and independent of input voltage over a given design range. A bias current is applied to the magnetic modulating transformer to controllably modify volt second capability of the device. In one embodiment, two transformers are employed, one of which is non-saturating and the other of which is a control transformer and saturates during its operation. In a second embodiment of the invention, only a single transformer, which is a saturating transformer, is employed.

Abstract: A three phase a.c. to d.c. voltage converter is disclosed. First, second and third rectifier circuits rectify respective phases of a three phase a.c. source into respective varying d.c. voltages. First, second and third converters connected to the output of the first, second and third rectifier circuits, respectively, each converting the varying d.c. input generated by its associated rectifier circuit into a substantial d.c. voltage. Each of the converters also generate at least one isolated d.c. voltage. At least one of the isolated d.c. voltages is applied to the input of each of the converters to reduce the harmonic currents fed back into the a.c. line.

Abstract: A resonant current-driven power source is disclosed. Preferably, the power source is a DC to DC converter regulator including an inductor and capacitor electrically coupled to one another and an input inverter which converts an input DC voltage into an AC voltage having substantially no DC component and applies the AC voltage across the inductor and capacitor in a manner which causes the inductor and capacitor to resonate with one another whereby an AC voltage appears across the capacitor. An output circuit converts the AC voltage appearing across the capacitor into a DC output voltage. A control circuit is provided for controlling the operation of the inverter circuit in a manner which controls the magnitude of the output voltage.

Abstract: A high voltage power supply that produces a relatively high current at a relatively low voltage D.C. output and a relatively low current at a relatively high voltage D.C. output is driven from a common transformer winding. The low voltage is produced by a rectifier bridge and the high voltage is produced by a full wave voltage doubler type circuit that includes rectifier elements of the bridge. However, the high voltage main storage capacitor is isolated from low voltage currents and the low voltage main storage capacitor is isolated from high voltage currents.

Abstract: A light amplification device utilizes a light intensification tube and optical feedback means for feeding back to the intensification tube for further intensification an image already intensified thereby. The feedback means is connected in such a manner that the fed-back image and the image being intensified for the first time are fed into separate, non-overlapping portions of the input surface of the light intensification tube.

Abstract: A d-c to d-c converter utilizing a resonant inductor to neutralize capacitive losses is disclosed. In most high voltage d-c power supplies, a step-up transformer is employed as the conversion element from the low voltage source to the high voltage output. Such transformers exhibit capacitive losses resulting from intra-and inter-winding capacitances. When utilizing a large step-up transformer wherein the turns ratio n=N.sub.p /N.sub.s is much less than 1, the capacitive losses result in a sharp decrease in the load to source voltage ratio thereby reducing the power available to the load. The present invention compensates for these losses by providing a resonant inductor which forms, at the operating frequency of the transformer, a resonant circuit with the equivalent Thevenin capacitive reactance as viewed from the primary side of the transformer resulting from these losses.

Abstract: A high voltage power supply for a capacitive load switches between two different voltages of the same polarity relative to ground within about 15 microseconds and is useful as the switching supply for beam penetration cathode ray tubes in short range radar systems. The power supply comprises two power supplies of different voltages which are selectively connected to an output capacitive load. The lower voltage supply is connected directly to the load through a low voltage clamping diode. The higher voltage power supply is connected in series with an inductor, which is, in turn, connected to the load through an up-switch circuit which is closed to increase the power supply output voltage to an upper level and a down-switch circuit which is closed to reduce the power supply voltage to a lower level. Each switch consists of one or more transistors in series with a switching diode.

Abstract: A low light level camera includes a plurality of identical modular-type intensifier assemblies which are removably clamped together, and are connected in electrical parallel with one another. The intensifier assembly is axially movable with respect to the camera frame and lens for focus adjustment.