Abstract: A method for controlling magnetrons with regard to their microwave power in those cases where a multiple of magnetrons are present. The method includes connecting two or more magnetrons in parallel with a power unit operative in generating a high voltage for operating the magnetron is connected to respective magnetrons and includes a current measuring circuit by which the anode current passing through respective magnetrons is measured on the high-voltage side of the magnetrons. The current measuring circuit is galvanically separated from a control circuit, which is arranged to control the anode current of a respective magnetron in response to a signal received from the current measuring circuit. Also an arrangement for carrying out the method.

Abstract: A discharge lamp energizing arrangement comprises a starter and a generator adapted to maintain a discharge current in the lamp. The generator includes a first circuit arranged to couple in series a D.C. voltage source, a first switch and a second switch. When the first switch is closed the second is open and vice versa. A second circuit, arranged to couple an inductance and the lamp in series, is connected in parallel with the second switch. The switches are operated by a first control means which employs the signals received from an oscillator. The starter includes a third switch connected in parallel with the lamp terminals. The third switch is operated by a second control means itself operated by the first control means. When the energizing arrangement is turned on the third switch is closed and it subsequently reopens on the first occasion that the first switch passes from the closed to the open state.

Abstract: A starting and operating circuit for a super compact fluorescent lamp includes ballast and discharge circuits for applying current to the filaments of the lamp and then apply starting pulses which enable the lamp to commence operation. The circuits include discharge devices and assure operation and proper starting of the lamp under low temperature as well as moderate temperature conditions.

Abstract: An attachment is provided for connection in fluorescent lamp circuits for reducing power consumption. The attachment is particularly designed for use with fluorescent lamp circuits having an encapsulated ballast including a transformer and capacitance. The attachment includes an isolation transformer with a capacitor and a resistor connected across the transformer, and an inductance connected in line with the primary of the ballast transformer with a resettable thermal switch connected to shut down the ballast transformer in response to high current overload conditions, and a surge voltage protection circuit connected through the thermal switch to shut down the ballast in response to a ballast power factor capacitor failure. The ballast and power reducer cooperate to produce a substantially square wave output resulting in increased system efficacy, reduced lamp lumen depreciation, and increased lamp life.

Abstract: A power control device for a microwave cooking oven includes a regulator of the anode voltage of the magnetron and a heater voltage source. The anode voltage regulator includes a d.c. voltage bridge-type converter, a transformer, a rectifier and a filter. The heater voltage source includes a half-bridge d.c. to a.c. voltage converter. The half-bridge and bridge converters are controlled each by signals coming from the respective generators of pulse sequences.

Abstract: An electron emission device for attracting electrons emitted from an electron emission element to an anode, includes a current detector for detecting a flow-in current to said electron emission element and a flow-out current from the electron emission element. The difference between the flow-in current and the flow-out current is calculated and the voltage applied to the electron emission element is adjusted in accordance with the difference between the flow-in current and the flow-out cuttent.

Abstract: In a flat picture-reproducing device having a phosphor-coated faceplate (1) and a tray-shaped rear housing (2), a cathode formed by a periodic array of heating wires (7) is provided. This heating-wire array is followed by layers of focusing wires (8) and attracting wires (9) and by a perforated anode (5). A segmented counterelectrode (6) is located behind the heating wires (7).

Abstract: A method for operating an ion source having a filament-cathode and an anode. The method includes supplying direct current electrical power between the anode and the filament-cathode characterized by substantially constant arc current there between and varying arc voltage on the filament-cathode. Direct current electrical power is also supplied across the filament-cathode. The value of the arc voltage is monitored and the magnitude of electrical power supplied to the filament-cathode is altered in response to detected changes in the arc voltage to return the arc voltage to substantially a preset reference value. The monitoring step and the altering step are carried out at regular preset intervals. The altering step includes deriving an filament power error signal as a prearranged function which includes the difference in values between the monitored arc voltage and the preset reference value multiplied by a predefined integral gain value.

Abstract: A fluorescent lamp operating device having a power supply, a circuit for converting the output power from the power supply into a high-frequency power, a lighting circuit connected to a secondary side of a transformer of the high-frequency power converter circuit to light a fluorescent lamp, a circuit for preheating the filament of the fluorescent lamp, a switch circuit including diodes and at least one transistor connected in series with the fluorescent lamp in the lighting circuit, and a control circuit for turning off the transistor for a predetermined period when the power supply is turned on thereby turning off the lighting circuit to actuate the preheating circuit during this period. The control circuit turns on the transistor at the end of the predetermined period to thereby actuate the lighting circuit.

Abstract: The arrangement of this invention includes circuitry for sequentially lighting a series of lamps, followed by extinguishing them in unison; said circuitry including, in association with each lamp, at least one bi-metallic element for controlling the opening or closing of a switch.

Abstract: Surge currents which may arise in dc-illuminated incandescent lamp can be effectively limited by an apparatus comprising a low resistance (first resistance); another resistance (second resistance); a diode rectifier, the input terminal being connected in series to an ac source through the first resistance, and the output terminal being connected in series to an incandescent lamp through the second resistance; a voltage regulator diode connected in parallel with said diode rectifier; a capacitance (first capacitance) connected in parallel to the input terminal of said diode rectifier; another capacitance (second capacitance) connected in parallel to the output terminal of said diode rectifier; a switching device connected to the second resistance; and a timing circuit connected to said switching device in a manner that the switching device shorts the second resistance after a lapse of a prescribed time upon switching-on of the ac source.

Abstract: The anode and cathode of an X-ray tube are connected to a high-voltage power source respectively, through corresponding tetrode tubes, and the center metal electrode of the X-ray tube is grounded. The tetrode tubes are simultaneously turned on and off upon receipt of a control signal. An abnormal current, which flows through the center metal electrode due to a short-circuiting fault of the tetrode tube connected to the cathode of the X-ray tube, is detected during an OFF period of the tetrode tubes. Upon detection of the abnormal current, the tetrode tube connected to the anode of the X-ray tube is forcedly turned on, thus preventing the fusion of the center metal electrode in the X-ray tube.

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: A rapid-start fluorescent lamp has a tubular envelope with a phosphor-coated inner wall, a pair of spaced electrodes and a pair of electrical leads sealed into the ends of the envelope with one electrical lead directly connected to the electrode and the other electrical lead connected through a bi-metal circuit breaker to the electrode with the circuit breaker formed to open-circuit at a given range of temperatures. Also, the discharge lamp is fabricated by preparing a phosphor coated envelope, forming a pair of end members having a pair of electrical leads, a bi-metal circuit breaker and electrode, sealing the end members into the envelope, heating and exhausting the envelope, heating the electrodes, dispensing a fill gas and mercury into the envelope, pinching off the exhaust tubes of the envelope and severing the fuse member of the circuit breaker.

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 rapid-start fluorescent lamp has a tubular envelope with a phosphor-coated inner wall surface, a pair of spaced electrodes and a pair of electrical leads sealed into each end of the envelope with one electrical lead connected directly to the electrode and the other electrical lead having an integral circuit breaker connected to the electrode and formed to disconnect the electrode from an energy source during lamp operation. Also, the rapid-start fluorescent lamp is fabricated by preparing a phosphor coated envelope, forming a pair of end members having a pair of leads and an integral circuit breaker with one lead connected directly to the electrode and the circuit breaker connecting the other lead to the electrode, sealing the end members into the envelope, heating and exhausting the envelope, heating the electrodes via the circuit breaker, dispensing a fill gas and mercury into the envelope and pinching off the exhaust tubes of the envelope.

Abstract: Apparatus and method for substantially equalizing the potential drop along a line cathode used in an electron beam source adapted for use in a flat display device. The apparatus and method ensure that electrons from a power source are fed through both ends of the line cathode, substantially simultaneously. Thereby, the potential drop along the axial length of the line cathode is decreased, improving the uniformity of brightness of the display.

Abstract: A low wattage metal vapor discharge lamp starting and operating apparatus includes an inductive ballast connected to one of a pair of terminals connectable to a low voltage source, a metal vapor discharge lamp coupled to the ballast and to the other one of the pair of lamp terminals and a non-linear dielectric element shunting the discharge lamp with the ballast and non-linear dielectric element providing a potential within about 600 usec of current reversal of the source voltage in an amount sufficient to initiate operation of the discharge lamp.

Abstract: An apparatus for essentially eliminating variations in luminescence (i.e., inverse shadowing) in an electroluminescent (EL) display is disclosed. The pixels of an EL display are driven to their light emitting voltage with a signal having a rise time dv/dt at and above the pixel light emitting threshold voltage which is independent of the number of pixels ON in each display row. The result is that each ON pixel in the display exhibits substantially the same luminescence.

Abstract: The invention is directed to a method of preventing cathode damage when switching on an electron gun having a field emission cathode assembly including a cathode, a first electrode and a ground electrode. During normal operation of the electron gun, an extraction voltage is applied across the cathode and the first electrode and an accelerating voltage is applied across the cathode and the ground electrode. A direct galvanic connection is established between the cathode and the first electrode prior to normal operation of the electron gun. During a burn-in period, only the accelerating voltage is applied. This accelerating voltage may include an overvoltage of up to twenty percent. Then the galvanic connection between the cathode and the first electrode is interrupted and the extraction voltage is applied. An arrangement for carrying out the invention is also disclosed.

Abstract: A film video player includes an electronic strobe light operable for repetitively firing a flash tube, to flash illuminate a solid state image sensor via a high-intensity light pulse projected onto photographic film at the vertical retrace rate of a standard television signal. A current sink circuit is provided for drawing a flash tube simmer current, to maintain an arc in the flash tube between sensor-illuminating pulses. Sensing circuitry, coupled to a junction common to the flash tube and the current sink circuit, produces a control signal corresponding to whether or not the flash tube is conducting simmer current. Switching circuitry, responsive to the control signal at the vertical retrace rate, (1) causes the overriding of the operation of a flash tube trigger circuit when the control signal indicates that the flash tube is conducting simmer current, and (2) causes the operating of the trigger circuit when the control signal indicates that the flash tube is not conducting simmer current.

Abstract: A duty cycle power control circuit for a magnetron including a power transformer having a primary winding, a secondary anode winding for supplying anode voltage to the magnetron and a secondary filament winding for energizing the filament of the magnetron. In the illustrative embodiment the power transformer primary winding comprises a main winding and a serially connected standby winding. Duty cycle controlled switching devices are effective in a standby state to connect the main winding in series with the standby winding across an external power supply and are effective in the power on state to disconnect the standby winding and connect the main winding directly across the external power supply.

Abstract: A rapid-start fluorescent lamp includes a circuit breaker having a pair of electrical conductors sealed into a bulb and connecting a lamp lead to the electrode of the lamp. The circuit breaker includes first and second electrical conductors and a bi-metal strip having a first end portion connected to a first conductor and a second end portion connected to a second conductor at ambient bulb temperature, disconnected therefrom at a higher given range of temperatures, and the portion of the bi-metal strip intermediate the end portions connected to the second electrical conductor at temperatures higher than the given range of temperature.

Abstract: A Varistor (which is a non-linear impedance means) is connected in series with the primary winding of a current-transformer; and this series-combination is connected across the fluorescent lamp to be started. Before the lamp starts, the voltage across it is limited in magnitude by the voltage-clamping effect of the Varistor; and the current then flowing through the Varistor is transformed by the current-transformer and applied by way of separate secondary windings to each of the lamp's cathodes for heating thereof. A special high-voltage tertiary winding on the current-transformer provides for lamp starting aid voltage.Thus, the lamp may be gently and rapidly started in the Rapid-Start mode.However, as soon as the lamp starts, the voltage across the lamp diminishes to a magnitude lower than that required for current to flow through the Varistor.

Abstract: A rapid-start fluorescent lamp includes a pair of spaced electrodes within an envelope with one electrical lead connected to an electrode and the other lead coupled to the electrode by a thermally-sensitive bi-metal strip whereby one end of the bi-metal and one end of a conductor are formed to provide a straight member within a U-shaped member such that the straight U-shaped members are in electrical contact at temperatures above and below a given range of temperatures and electrically disconnected at the given range of temperatures.

Abstract: A rapid-start fluorescent lamp has a thermally-sensitive circuit breaker disposed thereon for disconnecting the electrodes of the lamp from an energizing source at a given range of bulb temperatures and for connecting the electrode to the energizing source at bulb temperatures above and below the given range of bulb temperatures whereby the electrodes are energized during lamp manufacture and until conductivity of the lamp is established.

Abstract: An energization arrangement for a discharge lamp includes a DC/AC converter to which a discharge lamp (81) is connected. The lamp is shunted by a relay contact (90) to obtain an electric circuit through which two electrodes (83, 84) of the lamp can be preheated. It is advantageous to insure that the relay contact is closed before a voltage occurs between the electrodes of the lamp. This prevents the lamp from exhibiting a transient flash at too cold electrodes. A timing circuit (40-47) ensures that the relay contact remains closed for about 1 second, after which the lamp ignites with warm electrodes. No electrical losses occur in the relay winding (30) during operation of the lamp.

Abstract: To provide for reliable starting of compact-type fluorescent lamps, or ot discharge lamps difficult to start, a voltage divider which is formed only by serially connected capacitors (C1, C2) is connected across the lamp (L), the junction point (5) of the voltage divider being connected to a charging circuit formed by a resistor (R1) and a capacitor (C3). The junction (4) between the charging resistor and capacitor (R1, C3) is connected through a diac (D) to the trigger or gate electrode (3) of a triac (T) connected across the lamp. Preferably, the capacity relationship of each one of the capacitors (C1, C2) of the voltage divider to the trigger capacitor (C3) is between about 1:1 and 1:5, desirably about 1:3. The time constant formed by the charge circuit (R1, C3), preferably, is between about 4 to 6 milliseconds, so that the charge time of the trigger capacitor (C3) is sufficiently long to provide multiple starting pulses to the triac (T) at peak values. A circuit to provide for polarity independence (FIG.

Abstract: A rapid-start fluorescent lamp includes a pair of spaced electrodes within an envelope having a fill gas and a phosphor-covered inner wall surface with a circuit breaker having a glass bulb with a wall thickness in the range of about 0.016 to 0.018 inch positioned within the fluorescent lamp.

Abstract: In an auxiliary-voltage DC source for supplying an electric circuit and, more particularly, one at a high potential in an electron gun without an isolation transformer, the primary winding of a current transformer is located in an alternating-current section of the electric circuit. The current transformer has at least one secondary winding which is connected through a rectifier to a parallel regulator for providing the auxiliary-voltage.

Abstract: A process for operating a discharge lamp with an arc drop of not less than about 75% of a given service voltage includes the steps of series connecting a ballast and discharge lamp, coupling the series connected ballast and discharge lamp to a service voltage source and shunting the discharge lamp with a means for developing a pulse potential at or near the beginning of each half-cycle of the service voltage. Also, a series connected inductive ballast and discharge lamp are connected to a service voltage source and a non-linear dielectric element and preheat switching means each shunting the discharge lamp.

Abstract: A failure detection circuit for a center metal grounded type X-ray tube. If the high voltage applying line for the anode side is kept opened and simultaneously for the cathode side is closed, the extraordinary cathode current may flow from the cathode through the center metal to the earth, which may cause a failure of the X-ray tube. In order to avoid such problem, there are provided the anode/cathode failure detectors which may interlock the operation of the X-ray radiation control circuit so as not to apply high voltages to the anode/cathode of the X-ray tube when failed in the high voltage apply lines.

Abstract: A plurality of heater elements are heated using a DC voltage to render the display brightness of a fluorescent indicator tube uniform. A circuit comprises a first circuit for intermittently applying a heater current to the indicator tube at a predetermined interval, and a second circuit for preventing the indicator tube from developing a display during heating the heater elements.

Abstract: A method of controlling the power output of a magnetron tube, and an electric power supply for supplying power to the tube. According to the method, power is continuously supplied to the magnetron heater. At the same time, a voltage is continuously applied across the anode and the cathode of the tube. This voltage across the anode and the cathode varies in cycles between a first value, which is substantially at or below the threshold voltage of the magnetron tube, and a second value, which is above the threshold voltage. The average magnetron power output is determined by the proportion of each cycle during which the voltage across the anode and the cathode is above the threshold voltage.

Abstract: A ballast circuit for a fluorescent lamp including a gaseous discharge light bulb which for a given input power produces a decreasing amount of light as the bulb temperature decreases below a designed operating temperature at which the amount of light produced is a maximum, the ballast circuit being adapted to be connected in series with the bulb and having a first impedance at the designed operating temperature.

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: 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: The disclosure relates to an X-ray photographic apparatus which can prevent the overshoot of the tube current, which is apt to generate at the start of X-ray radiation. The apparatus comprises an integration capacitor which is charged by the preset preheating level setting voltage during the preheating period, an integration circuit which integrates the difference between the reference voltage and the detection voltage corresponding to the X-ray tube current during the X-ray radiation and a filament heating current control circuit driven by said integration circuit.

Abstract: A high-voltage power supply for an electron-beam gun with a heatable cathode and an anode and of the type having an electronic switch connected in the current circuit for the cathode and controllable for blocking the current to the cathode, includes an impulse protecting filter connected in the current circuit for the cathode. The filter comprises a capacitor connected in parallel to the cathode, a choke connected in series with the cathode current circuit, a blocking diode and a discharge resistor connected in series therewith, with the diode and resistor connected in parallel with the choke.

Abstract: A system for the control of power of a high-voltage electron beam generator having a cathode and a control electrode for the cathode, has a controller at ground potential, a pulse generator for the production of square-wave voltage pulses symmetrical with ground potential, a transformer for transferring high-voltage potential to the beam generator including a primary winding substantially at ground potential and a secondary winding at high-voltage potential, a full-wave rectifier connected to the secondary winding and a filter connecting the rectifier to the cathode and to the control electrode. The filter comprises an LC combination of at least two LC members connected in series, in conjunction with at least two capacitors, one parallel to the cathode-control electrode and the other parallel to the full-wave rectifier, the resonance frequencies of the LC members being in a ratio of approximately 2:1.

Abstract: In a circuit for an ionization vacuum gauge having a thermionic filament, a control circuit receptive of a control current for controlling the filament and a switch for applying the control current to the control circuit, a circuit is provided for indicating a filament interruption independent of the state of the switch. The circuit includes at least one resistor by-passing the switch to provide a continuous sensing current to the filament and a detector for detecting the interruption in the sensing current and for indicating such an interruption.

Abstract: A field emission electron gun including a cathode, a control electrode which is disposed in the vicinity of the cathode, an anode which is disposed for accelerating electrons emitted from the cathode, and a source of a D.C. voltage to be applied between the cathode and the anode. Also, there is provided a switching arrangement capable of changing-over a potential of the control electrode between ground potential and a potential of the cathode, and an arrangement capable of varying relative positions of the cathode and the control electrode.

Abstract: A high power tube in applications requiring reduced AC hum in the amplified signal, utilizes a direct current heated filament. In order to reduce the incidence of tube failure and maintain a stable mode of operation, the direct current is produced by a regulated source of DC voltage. The regulated source includes a transformer having a primary winding coupled to a source of alternating line voltage and also includes a secondary winding at which a transformed low voltage is generated. A rectifier is coupled to the secondary winding for rectifying the transformed voltage to produce a pulsating direct voltage which is applied to the tube filament by a filter. The primary winding of the transformer is coupled to the AC source by means of a saturable reactor. A control circuit senses the voltage across the filament and controls the reactor in a feedback manner.

Abstract: A filament heating apparatus for an X-ray tube having an isolation transformer through which a control signal is digitally transmitted regulates the filament current to be constantly stable. The control signal is comprised of one of a reference signal based upon the characteristics of the X-ray tube and a component of the filament current.

Abstract: A cathode current control system comprising an electron discharge device having a tubular envelope wherein an electron gun is disposed to beam a cathode current of electrons onto a spaced anode collector electrode, the gun including an electron emitting cathode, an apertured control grid electrode spaced from the cathode, and a further spaced series of beam forming electrodes; and external circuit means connected to the cathode and other electrodes of the device for maintaining the electrodes at respective predetermined electrical potentials relative to the cathode and for maintaining electron emission from the cathode sufficient for providing a predetermined level of cathode current associated with the predetermined electrical potentials of the electrodes.

Abstract: A indicator device with vacuum fluorescence elements controlled or triggered by a driving circuit, the heaters of the elements lying in a heating circuit. The heating circuit contains a switch which is controlled or triggered by a clock generator and the clock pulse frequency and the pulse duty factor of the control signal pulses are selected such that the effective value of the pulsed heating current is equal or approximately equal to the dc heating current in accordance with the elements.

Abstract: An improved ballast circuit for a low pressure gas discharge lamp having two filament type electrodes at opposite ends of the lamp is disclosed. The ballast circuit includes a first device for providing a high AC voltage for application across opposite electrodes of the lamp; a solid state controlled current source for providing a controlled current to the first device for enabling the first device to apply the AC voltage across the lamp electrodes to illuminate the lamp, wherein the voltage placed across said electrodes is non-sinusoidal; and a second device coupled to the first device for inhibiting the non-sinusoidal voltage from causing mercury migration in the lamp. The second device includes circuit connections for enabling current flow through only one filament of the lamp; and for biasing the voltage applied across the lamp about a DC level for balancing the effect upon mercury migration within the lamp caused by enabling current to flow through only the one filament.

Abstract: An energizing circuit for gas discharge lamps for room or street lighting or for lights used in document copying machines and the like comprises means for continuously energizing the same at a low non-useful light producing level when such lamps are not needed by a voltage which strikes an arc and maintains a low level of ionization with an infinitesimally small current and very little energy drain. This voltage may be an AC voltage or a DC voltage supplied by a unique circuit including a number of DC voltage sources, rectifiers, voltage adjusting and current-limiting impedances and electronic switches. The lamps are energized by AC or pulsating DC supplied by the aforesaid or other electronic switches operated at a high frequency of at least about 20-30 kilo-Hertz.

Abstract: A vacuum fluorescent display system for displaying a plurality of illuminable characters includes a plurality of segmented anodes, at least one cathode filament, a plurality of control grids interposed between the anodes and the cathode filament and circuitry for controllably powering the cathode filament and for sequentially driving the control grids whereby selected segments of the anodes are sequentially illuminated and the luminous intensity of the segments of each of the anodes is substantially the same. The cathode filament is controllably powered by removing and applying heating power in response to driven and undriven states respectively of the control grids. By controlling when heating power is applied to the cathode filament the voltage along the cathode filament is the same for each anode when the selected anode segments are sequentially illuminated thereby substantially eliminating variation in luminous intensity.