Abstract: An electronic ballast system includes a first capacitor (C.sub.2) electrically coupled to the first filament (30) of a gas discharge tube (12) and becomes the power supply of the gas discharge tube (12) subsequent to both its charging and discharging operations. The collector (38) of a transistor (Tr) is connected to the first capacitor (C.sub.2). The primary winding (22) is connected to the first capacitor (C.sub.2) and the collector (38) of the transistor (Tr) in parallel relation. The transformer (t) includes a secondry winding (24) which is connected on opposing ends thereof in feedback relation to the base (44) and emitter (42) of the transistor (Tr). Pulses of opposing current polarity (122 and 124) generated through the secondary winding (24) alternately provide conducting and non-conducting states for transistor (Tr) to discharge and charge the first capacitor (C.sub.2) through gas discharge tube (12) to provide a power source for operation of gas discharge tube (12).

Abstract: A fluorescent lamp is adjusted in illumination intensity by controlling the DC current in the lamp during each alternate direct current flow through the lamp. The magnitude of the current applied to the lamp is set each time the direction of current through the lamp is switched, and the current change between switch times is limited. Inductors are used as current change limiting devices so that in each direction of current flow through the lamp, the current can not rapidly change. The amount of current is set, and the direction of current flow is switched when a current monitor detects that the current through one of the inductors is equal to the current desired for the operating point of the lamp. In this way, uniform selectable illumination levels may be achieved even though the lamp is operating in the negative resistance portion of its resistance characteristic.

Abstract: An electronic device (20-61) for the starting and a.c. operation of a capacitively stabilized discharge lamp (7) includes a controlled semiconductor switching element (22) which, in the operating condition of the lamp, is briefly conductive in each half cycle of the AC supply. The control circuit of the semiconductor switching element (22) includes a second switching element (25) which, during the starting procedure of the lamp, ensures that the semiconductor switching element (22) is made conductive only every alternate half cycle thereby to improve the ignition of the lamp.

Abstract: A high pressure discharge lamp apparatus comprises:a discharge tube and a current limiting device such as a choke coil connected in series for connection across an A.C. power source, anda pulse generator connected by its output terminal in parallel to the discharge tube,the apparatus is characterized in that:said pulse generator impresses reignition pulses on said discharge tube at least during a period defined as from a zero-cross point of the source voltage of the power source to a phase defined by a peak of reignition voltage of lamp voltage waveform when no reignition pulse is impressed on the discharge tube, thereby retaining lamp current of the discharge tube without forming zero-current period,thereby the lamp is stably lit with such a high lamp voltage as is almost equal to the power source voltage and the power of reignition pulse can be saved without harming stability of lighting. Thus a stable lighting of the high pressure discharge lamp with a a high power efficiency becomes possible.

Abstract: In a high pressure discharge lamp apparatus comprising a discharge tube and a current limiting device connected in series, an over-current protecting semiconductor switching device such as a triac (TC) is further connected in series to said discharge tube,the triac (TC) being controlled of its firing angle responding to an output of a current detection circuit which detects a change of the lamp current through a change of the lamp voltage, anda pulse generator is further connected in parallel to the discharge tube and gives reignition pulse thereto at least during the zero-current period in each cycle of the lamp current.

Abstract: A starter circuit for a high power discharge lamp connected to an AC source via a series inductor. The starter circuit comprises a capacitor connected in series with a triac across the lamp, and a branch including a first resistor connected in series with a zener diode and a second resistor between the junction of the capacitor and triac and one side of the AC source. A driving circuit for the triac includes a diac connected to the junction of the second resistor and zener diode.

Abstract: The input energy to a gas discharge lamp is controlled over a given range to obtain output light regulation in a controlled fashion for different kinds of gas discharge lamps, including fluorescent lamps, high intensity discharge lamps and others associated with any type ballast, including conventional non-dimming type ballasts. A suitable circuit switches each half wave of an input a-c wave form from some instantaneous value greater than zero to a substantially zero value and then back to a value greater than zero one or more times in each half cycle. The time duration of the substantially zero energy interval is varied to vary the total energy applied to the gas discharge lamps. In a preferred embodiment, a first high speed electronic switch is connected in series with the a-c source and lamp ballast and a high speed electronic shunt switch is connected across the a-c line and ballast input. The series switch is opened to produce the zero energy interval.

Abstract: A discharge lamp starting device such as for a fluorescent lamp in which a nonlinear capacitor is connected in parallel with a discharge lamp with a Zener diode connected in series with the nonlinear capacitor. A semiconductor switching device, such as a diode thyristor, is connected in parallel with the discharge lamp. Due to the presence of the Zener diode, the semiconductor switching device can have a wide range of threshold voltage so that the cost of the device is low.

Abstract: A solid state flasher relay of the type for switching an AC or a DC voltage across first and second loads interconnected at a common junction. More specifically, a solid state flasher relay is disclosed wherein shunting transistors are selectively controlled so that an AC or a DC voltage applied across two input lines connected to the first and second loads can be either shunted from the first input line to the common junction thereby providing the voltage across the second load, or shunted from the second input line to the common junction thereby applying the voltage across a first load.

Abstract: The emitted light intensity of an electronic flash tube is maintained constant over a given time period by connecting the electronic flash tube in series with an inductor and a switching element across the main capacitor for energizing the flash tube, with a diode being connected across the serially connected flash tube and inductor and a polarity opposite to the current flow from the main capacitor to the flash tube. The switching element is intermittently turned off and on in accordance with the intensity of the light emitted from the flash tube. While the switching element is being turned off, the flash tube is energized by the energy stored in the inductor in the form of a magnetic field. An auxiliary capacitor may be provided across the flash tube. The flash light intensity may be monitored by the measurement of the emitted light, or by the detection of the voltage across the flash tube, or by the detection of the current flowing into the flash tube.

Abstract: High frequency circuit for operating gaseous discharge lamps includes oppositely poled controlled semiconductor switches connected to a resonant circuit comprising a capacitor and inductor connected to the lamp load and serving both as a high-frequency ballast for the lamp and to effect alternating turn-off of the semiconductor switches. Diodes are connected to the switches in a manner to provide energy pulses on the lamp load without return to the supply source. A control circuit is provided for alternately triggering the semiconductor switches into operation.

Abstract: A voltage multiplier device is disclosed which includes a circuit and a means for coupling the circuit between a television filament transformer and the heater filament leads of a C.R.T. picture tube of a television set. The device is operative to develop a voltage across the two leads of the C.R.T. heater filament that is greater than the voltage developed across the two secondary leads of the transformer.

Abstract: An electronic starter for a discharge lamp includes an SCR controlled by a temperature-sensitive element and an auxiliary switch arranged so that no current flows in the temperature-sensitive element when the lamp is in operation, whereby rapid restarting of the lamp occurs after a brief interruption of the AC supply voltage. The temperature-sensitive element may be thermally coupled to an inductor in series with the lamp ballast thereby to limit the ballast current in the event the lamp fails to ignite.

Abstract: Circuitry directed to the rapid de-ionization of ultraviolet detectors by increasing the mobility of the ionized gases within the tubes which will enable the tubes to more effectively operate at low temperatures. The circuitry includes connecting circuitry for shorting the elements of the tube such that they will be at the same potential immediately after firing and also includes circuitry for the shunting of the tube immediately after firing to limit the number of ions generated in the discharge process. The shorting of the elements increases the surface area of negative electrodes for the recapture of the ions and the distance through which the ions must travel is reduced by a factor of one-half.

Abstract: The invention relates to a relay starter for a discharge lamp wherein the lamp is stabilized by a series arrangement of at least an inductor and a capacitance. Also included in series with these stabilization elements and the lamp is an energizing winding of a relay having a normally-closed contact disposed in a circuit which shunts the lamp.A diode is also disposed in the circuit which shunts the lamp, so that if the lamp does not ignite, current flows for a short period of time through the diode which thereby charges the capacitor. When this capacitor has received a sufficient charge no further current flows either in the lamp circuit or in the shunting circuit so that the entire circuit is put out of operation.

Abstract: A fluorescent lamp fires more quickly at low temperature and its service life is lengthened if the input terminals of a full-wave rectifier are connected to the lamp electrodes and a resistor and capacitor are connected in parallel circuit between the output terminals of the rectifier. The voltage pulses applied to the electrodes prior to firing are reduced in peak amplitude and broadened by the improved circuit.

Abstract: A circuit for operating an arc discharge flash lamp that is directly coupled across an alternating current (AC) source. The lamp is ignited by a high voltage pulse generated by a trigger circuit energized by the AC source. A voltage multiplier, such as a doubler circuit, is connected across the flash lamp for increasing the voltage across the lamp above that provided by the AC source, thereby facilitating starting of the lamp by the trigger circuit.

Abstract: The HID lamp starting and operating apparatus of the invention includes inductive ballast means containing a winding and a core of magnetic material which may form a reactor or a transformer, and such winding is adapted for connection in circuit with an HID lamp; source means for supplying a cyclically varying AC voltage to said ballast means so as to provide AC voltage across said winding; first semiconductor switch means and a first capacitor means are coupled in circuit to said winding, responsive to said voltage across said lamp attaining a first predetermined instantaneous AC level, possible only during the time period before the lamp starts, for discharging the capacitor means through at least a portion of said winding at least once in each cycle of AC voltage to thereby generate high voltage pulses across said lamp and further responsive to said lamp being in the operating condition for terminating such capacitor discharging function; and second semiconductor switching means, including timing means ass

Abstract: An "add-on" instant restrike device for a high-intensity discharge lamp ballast. The device initiates an operating discharge in an HID lamp when it is still hot from previous operation. The device consists of a high-voltage pulse-generating section which initiates breakdown in the lamp and an intermediate-voltage generating section which coacts with the existing ballasting capacitor to apply an intermediate potential to the lamp after initial breakdown. The intermediate potential has sufficient duration to permit one of the lamp electrodes to form an operating hot spot thereon to establish stable lamp operation.

Abstract: Pulse operating circuit for high intensity gaseous discharge lamps is provided with improved lamp starting device. The circuit comprises a direct current supply, a transistor switch in series with a ballast inductor and a lamp across the DC supply, an SCR switch connected across the inductor, a control circuit connected to the transistor switch for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle, a sensing circuit for sensing the voltage across the inductor, and a variable SCR firing control circuit connected to the SCR and the first mentioned control circuit and responsive to the sensing circuit to control the firing of the SCR for limiting the peak current through the transistor switch during the lamp starting and warm-up interval.

Abstract: Alternating current energized appliances, particularly lamps, are extinguished in delayed fashion with the power delivered to the appliance being sharply reduced during at least the last portion of the extinction cycle. Delayed interruption of power is accomplished by means of a first circuit, including a series connected diode and heater, connected in parallel with the appliance and a second circuit, including a series connected diode and temperature responsive switch, connected in parallel with a main power switch. The heater and temperature responsive switch are mounted in proximity to one another and the diodes are arranged in opposition.

Abstract: The invention relates to an arrangement for starting and supplying a discharge lamp provided with cold electrodes. The lamp is shunted by a starter circuit which consists of a series arrangement of at least a capacitor and a controlled semiconductor switching element having a bidirectional thyristor characteristic.According to the invention a resistor with a positive temperature coefficient is connected in series with the capacitor and the controlled semiconductor switching element. If the lamp fails to ignite the device produces substantially no radio interference owing to the high-ohmic value of the PTC resistor produced by an increase in its temperature. Furthermore, a controlled semiconductor switching element having a low blocking voltage can now be used. Normal starting of the lamp is hardly affected by the PTC resistor.

Abstract: Color properties of high pressure sodium vapor discharge lamps are improved by disclosed operating circuit for applying pulsed direct current to the lamp. The circuit comprises a direct current supply circuit, a transistor switch in series with the lamp and the primary of a transformer connected across the supply circuit, a diode in series with the secondary of the transformer connected across the supply circuit, and a control circuit connected to the transistor switch for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle. The circuit produces pulse waveforms which provide substantial color improvement in the lamp and makes efficient use of the energy supplied from the power source.

Abstract: Color properties of high pressure sodium vapor discharge lamps are improved by disclosed operating circuit for applying pulsed direct current to the lamp. The circuit comprises a direct current supply circuit, a transistor switch in series with the lamp and the primary of a transformer connected across the supply circuit, a diode in series with the secondary of the transformer connected across the supply circuit, and SCR switch connected across the secondary of the transformer, and a control circuit connected to the switches for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle. The circuit produces pulse waveforms which provide substantial color improvement in the lamp and makes efficient use of the energy supplied from the power source.

Abstract: A transformerless Blumlein type circuit is combined with a novel clamper circuit for driving a cold cathode electron beam gun for a CO.sub.2 laser where the E-beam gun has resistance essentially infinite at the leading end of a driving pulse and has several ohms resistance at the end of the driving pulse. At the leading end of a driving pulse the voltage output of the Blumlein circuit is twice the rated load voltage since the load as infinite impedance. The clamper circuit limits the pulse voltage across the load to its rated voltage and the excess power from the Blumlein circuit over that required by the load is dissipated in the clamper circuit. The clamper circuit as variable impedance that is approximately the inverse of the load impedance during a driving pulse so that the Blumlein circuit looks into an approximately constant impedance equal to its impedance.

Abstract: The invention relates to a mixed-light lamp. According to the invention the lamp is connected to a cascade circuit of two capacitors and two diodes. The increase in voltage obtained with that cascade circuit is fed to an auxiliary electrode of the discharge tube of the mixed light lamp.All electric circuit element of the device are located within the lamp. The lamp described is particularly suitable to be operated by an AC mains circuit of a relatively low voltage.

Abstract: Operating circuit for gaseous discharge lamps, such as those of metal vapor type, having a ballast device of conventional type is provided with high voltage generating means for applying high voltage starting pulses on the lamp. The circuit may be combined with an auxiliary incandescent lamp for turning the latter on for safety lighting purposes when the gaseous discharge lamp goes out. The circuit includes an induction coil in series with the gaseous discharge lamp, a controlled switch connected to a tap on the induction coil, and a charging capacitor in series with the controlled switch. When used, the incandescent lamp is connected in series with the controlled switch in parallel with the charging capacitor.

Abstract: A spark source is disclosed having an analytical spark gap, a capacitor, a power supply for charging the capacitor, and an electronic switching tube connected in a series circuit between the capacitor and the spark gap. When the tube is rendered conductive by a triggering pulse or other signal, the capacitor is discharged through the spark gap and the switching tube, which carries the entire discharge current.

Abstract: In a microwave energy generating system, a combination of a magnetron which generates microwave energy and an inverter which converts DC voltage to high frequency AC voltage are employed. The magnetron includes a heater-cathode and an anode. The inverter includes a transformer having a gapped ferrite core, a center tapped primary winding which divides the primary into two portions, and at least a first high voltage secondary winding and a second low voltage secondary winding for the magnetron heater, and means for switching current through each winding half alternately at a periodic high frequency rate, substantially above 60 Hz., to produce a high frequency magnetic field in said ferrite core, and means, including inductor means, are provided for providing DC current into said primary winding at said center tap.

Abstract: Methods of driving a light-emitting diode (LED) or an injection diode at very high digital data rates using high speed emitter coupled logic (ECL) gates.

Abstract: Device for producing electrical pulses, comprising a charge circuit for a capacitor and a discharge circuit, characterized in that it comprises circuitry for storing the charge power brought into play when the voltage at the terminals of the capacitor has reached a given value and circuitry for restoring that power to the capacitor after its discharge.