Abstract: A power supply for helix and collector electrodes of a traveling wave tube is driven by an AC power source having a frequency of at least 500 KHz. The helix supply includes plural, stacked voltage doubler AC to DC modules responsive to the 500 KHz source. The collector supply includes plural AC to DC modules, each having a diode full wave rectifier bridge, connected in stacked relation. Each of the modules includes a transformer with a ferrite, toroidal core dimensioned so that it is not driven into saturation by the 500 KHz source. Each module also includes inexpensive, signal switching diodes having a recovery time of approximately 4 nanoseconds. The ratio of the collector to helix DC voltages is maintained constant by threading a common lead through the apertures of the toroidal cores of the helix and collector modules. A separate common lead threaded through the apertures of the toroidal cores in the collector modules is connected directly to the 500 KHz power source.

Abstract: A video apparatus capable of operating at different line deflection frequencies incorporates a CRT electron gun assembly heater supply voltage circuit that maintains a constant rms voltage level independent of the line deflection frequency. The heater supply includes a transformer winding located on the line deflection driver transformer. The duty cycle of the developed AC voltage waveform remains substantially constant independent of the line deflection frequency, so that the AC voltage may be applied to the heater circuit.

Abstract: An improved power supply system of smaller size and lower cost than prior art supplies is described for starting and maintaining the running of a deuterium arc lamp at a constant current level; by use of switching circuitry with solid-state components the necessity of transformers, relays and timing circuits has been obviated with a resultant major reduction in size, cost and cooling requirements of the supply; an improved starting sequence lengthens lamp cathode life.

Abstract: An electronics circuit for improving the fault isolation of failures between an electron tube radio frequency (RF) amplifier and its high voltage power supply is disclosed. High voltage power supplies control their output voltage by comparing a feedback voltage against a reference. This comparison is used to develop an error voltage which, in turn, drives a pulsewidth modulator that corrects the feedback voltage to the reference. The output of a digital-to-analog converter (DAC) is used as the reference voltage. The DAC is driven by a counter which would count to the correct reference voltage represented by a specific count. The final count is determined by a comparator which compares the counter output to the desired final count and stops the counter when it is reached.

Abstract: A current control circuit for high voltage applications includes series-connected high and low voltage sources through which the current to be regulated flows. The low voltage source is a capacitor which is periodically recharged through a flyback transformer by a series of constant energy pulses having a very low duty cycle. The peak value of the flyback pulses are detected to provide a "condition signal" which is representative of the state-of-charge on the capacitor and can be used to protectively inhibit operation of the control circuit and can, in a variant of the circuit be used as an error control signal to maintain the current at a constant level. In the preferred embodiment a sensing capacitor is placed in parallel to the pulsed capacitor to detect the fluctuations in potential and form a sense current which is representative of the regulated current and which is used in a feedback loop to form a control signal for maintaining the regulated current constant.

Abstract: Disclosed are a method and apparatus for rapidly heating a thermionic vacuum tube cathode, thereby enabling the vacuum tube to be placed in useful operation shortly after the tube is switched on. Rapid heating of the cathode is achieved by passing current through the cathode, thereby directly heating it. Simultaneously, the cathode is also heated by an indirect radiant heater and by electron bombardment by electrons emitted from the heater. When the cathode reaches its operating temperature, the direct heating current and the electron bombardment are stopped and the cathode is maintained at its operating temperature by the indirect heater alone. Cathode warm-up times of less than 1 second may be attained using this invention.

Abstract: A rapid-start fluorescent lamp system includes a ballast circuit, rapid-start fluorescent lamps and power reducing means for controlling the application of energy to the lamps. The power-reducing means controls the energy to N/O switches from the energy source upon ionization of the rapid-start fluorescent lamps.

Abstract: A circuit assembly for temperature-dependent cathode current tracking in traveling-wave tubes having control electrodes and cathodes with a predetermined cathode current, in combination with a power supply, includes a temperature-dependent network thermally coupled to a given point of the traveling-wave tube for measuring the actual temperature of the tube, and an electronic control circuit in the power supply connected to the temperature-dependent network for keeping the predetermined cathode current substantially constant by varying the voltage at the control electrode of the tube.

Abstract: A device to reduce power consumption in a rapid-start fluorescent lighting fixture having one or more lamps and a conventional ballast. The device includes a step-up isolation transformer, a capacitor connected in parallel with a bleed resistor and in series with a protective fuse all across the transformer. The device being mounted external of the ballast and wired in series between the ballast and the filament of a lamp to present a symmetrical load to the ballast circuit. In one embodiment the capacitor of the device is connected between the primary and secondary windings of the transformer by taps intermediate of the windings with an optimum connection at the center taps of the windings. In a second embodiment the capacitor is connected between either lead of the primary winding of the transformer and the center tap of the secondary winding.

Abstract: A picture display device including a picture display tube and a circuit for supplying the heater thereof with an increased heater voltage during a predetermined warming up period. The heater is connected to the secondary winding of an (auto) transformer, the primary winding of which is connected to a terminal of an a.c. voltage source, for example a winding provided on a line output transformer, the other ends of the primary and the secondary windings being interconnected and connected to a positive temperature coefficient thermistor and the other ends of the heater and the thermistor being connected to the other terminal of the source. The secondary winding has more turns than the primary winding.

Abstract: A starting circuit for discharge lamps includes a current limit device, a full wave rectifier circuit and a Cockcraft-Walton's circuit which are connected between a d.c. discharge lamp having a cathode and an anode and the input terminals of an a.c. power source. Moreover, the Cockcraft-Walton's circuit is constructed by sharing a rectifier with the full wave rectifier circuit and a preheating circuit is provided for the cathode and includes another rectifier of the full wave rectifier circuit and a switching device.

Abstract: To achieve an optimum reduction of the warmup time of a Wehnelt cathode, by maintaining a good efficiency, it is proposed to use as a cathode a triode system arranged within the usual cathode sleeve, with the inside of the base plate, on the outside of which the electron-emitting layer is deposited, serving as the anode, so that the electron-emitting layer is heated by the anode dissipation of the triode system.

Abstract: A thermionic fault current limiter utilizes either a vacuum or plasma environment for a plurality of spaced conduction electrodes. The electrode can be supported by insulative spacers with the electrode providing shadow shields for the supporting spacers. Electrode spacing, power density, temperature gradients, and control grids can be utilized for optimum operation and in establishing self-absorption of energy for a desired operating environment. Cesium desorption from the electrode surfaces can be utilized to enhance current termination.

Abstract: In the exemplary embodiment the temperature-dependent resistance of the cathode coil is taken as the measure of the instantaneous coil temperature and is employed for the purpose of dimensioning an increased filament power in the transition time between fluoroscopy and radiography, or for the purpose of dimensioning a heating pause in the transition time between radiography and fluoroscopy, respectively.

Abstract: A magnetron device emits through the filament terminals electromagnetic waves of a broad frequency band which act as noises to other electronic devices. The magnetron device comprises a filament or heater circuit for supplying heater voltage to the filament to emit thermal electrons from the cathode and an anode circuit for applying a required voltage across the filament and anode. The filament circuit is connected to one secondary winding of a power supply transformer and the anode circuit to the other secondary winding thereof. Connected to the anode power supply line is a filter device comprising a capacitor and a choking element having a sufficient inductance to reduce a relatively low frequency of the broad frequency band. This filter device is intended to reduce or suppress a large amount of the noise transmitted to the anode circuit out of a magnetron through filament terminals.

Abstract: A rapid start fluorescent lamp ballast with a secondary winding supplying lamp current and tertiary windings for supplying heater current, has a magnetic switch which senses current through the secondary winding and opens the heater current circuit after the lamp starts and draws operating current from the secondary winding. The current sensing magnetic switches shown are a slow acting relay with its coil in the secondary circuit and a magnetic reed switch physically disposed in the magnetic field of the secondary ballast winding.

Abstract: A system providing flickerless operation of a gaseous discharge lamp utilizes a DC voltage applied across the lamp electrodes. Low starting voltage and power consumption are obtained by applying an AC voltage across a grounded conductor member and adjacent lamp electrodes. This is a division of application Ser. No. 443,825, filed Feb. 19, 1974, now U.S. Pat. No. 3,890,540.

Abstract: A photodetector comprises an evacuated envelope with a transparent face plate. The face plate is selected from a material which causes total internal reflection of photons produced by Cerenkov radiation. In the evacuated envelope are an anode and a transmissive type photocathode. The photocathode is spaced apart from the face plate.

Abstract: An integral self-contained fluorescent lamp unit comprising an elongated lamp and an elongated ballast resistor carried in an outwardly extending housing member positioned alongside the lamp.

Abstract: A high emission of electrons, as a result of negative electron affinity, has been achieved from an insulating nitride coated with a film of an electropositive work function reducing material.

Abstract: An improvement for effecting rapid warm-up of the thermionic cathode means in a color CRT display device utilizing a degaussing circuit including a temperature responsive resistive element in series with the primary winding of an inductive means. A direct operational relationship is established between the degaussing and cathode heater circuits by having the secondary winding of the inductor series coupled therein. Upon simultaneous activation of both circuits, through a common switching means, a transitory surge of current is supplied by the degaussing circuit to the heater circuit, via the common inductor, to effect an accelerated temperature response in the heater.

Abstract: An integral self-contained fluorescent lamp unit comprising an elongated lamp and an elongated ballast resistor adjacent to and alongside the lamp. Metal strip heat radiators are positioned adjacent to and alongside the ballast resistor for dissipating its heat when operating.

Abstract: A ballast especially useful in forming symmetrical half cycles of lamp current during dim light level operation, and thus in overcomming a type of lamp flicker. The light level of the lamp is controlled by an intensity selector circuit which controls an auxiliary circuit that, in turn, controls the ballast circuit. The intensity selector circuit comprises an oscillator which produces timing pulses at a frequency controlled by a potentiometer. The oscillator operates a control switch in the auxiliary circuit and the control switch supplies gate current for a power switch. The power switch controls the ballast circuit which turns on the lamp during a portion of each current half cycle; the light level being determined by the length of the conduction portion of that half cycle. The ballast circuit comprises primary, secondary, and heating windings mounted on a common core. The primary winding is connected to ground through a resistor.