Abstract: A highly energy efficient lighting system for fluorescent lamps is provided comprising a blocking oscillator having a dimmer for reducing power consumption. In one embodiment a built in power supply transformer and a battery charger provides for AC operation, portability, and emergency lighting situations. The fluorescent lamp is excited in an energy efficient manner by a high frequency blocking oscillator circuit and the dimmer permits reduction of light output reducing power drain even further thereby enabling longer battery operation, reduced size, and reduced operation costs. Also the dimming feature is important in establishing a proper mood simulating candlelight, etc.

Abstract: A dimmer circuit for an HID lamp is provided for supplying a square wave current therethrough at a constant frequency, but whose duty cycle is variable dependent on a sensed current level. The circuit employs a first pair of transistor switches for reversing polarity through the lamp at a low frequency rate. Associated with each of those transistors is a circuit having a transistor switch connected to a drive circuit employing a timer network. The timer network produces an output that is a square wave, the leading edge of which occurs at regular intervals at a high frequency rate. The trailing edge occurs dependent on a dim/bright voltage setting and upon the amount of current through a sensing resistor in series with the lamp.

Abstract: A control circuit including at least one switch and a plurality of rectifiers for selectively applying a-c utility power to either or both of two remote electrically-powered apparatus at respective first and second states of rectification by means of a conventional two-wire interconnection cable. Where one of the apparatus is of a type, such as a motor, adapted to be powered by a full-wave a-c, the control circuit includes a relay and relay switch responsive to switch-selectable half-wave a-c for connecting the motor to receive full-wave power. In one disclosed embodiment, the two apparatus comprise a composite smoke detector and lamp fixture, and the control circuit provides continuous power at a first state of rectification to the smoke detector portion of the fixture and switch-selectable power at a second state of rectification to the fixture lamp.

Abstract: An oscillation generator providing a succession of oscillations repetitively and progressively varying in amplitude includes a feedback oscillator arranged to receive its operating voltage from a capacitor that is progressively charged from a periodically fluctuating voltage source by way of an SCR and a timing circuit arranged to progressively vary the timing during the fluctuation period of the source of firing signals applied to the SCR. The timing circuit includes a firing capacitor charged from a unidirectional source and semiconductor switches arranged, when the potential on the firing capacitor attains a predetermined level, to discharge the capacitor into the trigger electrode of the SCR. The time required for the potential on the firing capacitor to reach the predetermined level is varied by a saw-tooth generator that controls the charging potential for the capacitor.

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: An apparatus that provides constant illumination in response to an AC input power source having variable magnitude. The input power passes through a full wave rectifier and is then switched by a solid state switching device having conductive and nonconductive states to a passive L-C filter. The output of the filter energizes one or more lamps to provide the illumination. A phase control circuit is responsive to a sync signal from the full wave rectifier and a feedback signal from the output of the filter and controls the phase angle conduction time of the solid state switching device at a repetition rate related to the frequency of the AC input power to provide constant illumination from the lamp.

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 highly efficient tuned oscillator ballast circuit especially suitable for a fluorescent lamp load includes an oscillator circuit coupled to a pulsed DC potential source and having a tuned output circuit coupled to a load circuit, to a drive circuit for the oscillator which is dependent upon current flow in the load circuit and to a rectifier and charge storage and isolation and applying network coupled to the pulsed DC potential source and providing energy thereto whenever the potential decreases below a given reference level. A transient compensating circuit to protect the oscillator components from initial or "start up" transients is also included.

Abstract: A system for operating gas discharge lamps at high frequency from a high voltage supply, typically 115 V AC with a 160 watt, 25,000 Hz output. The system provides efficient conversion, having the capability of driving any number of lamps up to maximum wattage, inherent open-cirucit and short circuit protection, and higher efficacy from the lamps. Filament power may or may not be used. Filament power is not necessary under conditions when the lamps are forced into a glow discharge to charge each cycle through the use of a tuned resonant circuit. An unsaturated inverter provides fast cut-off times. Dimming capabilities may be provided.

Abstract: A circuit for the operation of fluorescent lamps which allows the current through the lamps to be raised above the manufacturer recommended limit without adversely effecting the lamps. Two oppositely poled diodes are connected to the two contact pins at each end of the lamps, and an AC voltage is applied thereto. The arrangement results in current through two properly poled diodes during one half cycle of the applied voltage, and through the two oppositely poled diodes during the second half cycle of the voltage. As a result of this alternate loading, the thermal stress on the lamp electrodes is substantially lowered, and the current through the lamp may be raised above the recommended limit. The AC voltage is preferably at a high frequency, for example twenty kilohertz, which results in illumination from the lamps originating along the glass walls due to the skin effect, and increases the illumination efficiency of the lamps.

Abstract: A circuit for the operation of fluorescent lamps which allows the current through the lamps to be raised above the manufacturer recommended limit without adversely effecting the lamps. Two oppositely poled diodes are connected to the two contact pins at each end of the lamps, and an AC voltage is applied thereto. The arrangement results in current through two properly poled diodes during one half cycle of the applied voltage, and through the two oppositely poled diodes during the second half cycle of the voltage. As a result of this alternate loading, the thermal stress in the lamp electrodes is substantially lowered, and the current through the lamp may be raised above the recommended limit. The AC voltage is preferably at a high frequency, for example twenty kilohertz, which results in illumination from the lamps originating along the glass walls due to the skin effect, and increases the illumination efficiency of the lamps.

Abstract: Apparatus for feeding a discharge lamp such as a mercury vapor lamp mounted in series with a choke from a direct current source comprising a chopper of direct current including an electronic switch and a detector of current intensity mounted in series with the choke. A first comparator compares the intensity of the current to a maximum level for opening the switch when the maximum level is reached and a second comparator compares the intensity of the current to a minimum value for closing the switch when the minimum value is reached. The lamp choke and current detector are connected in series with one another and a diode is mounted in parallel therewith and is oriented in the direction to pass current from the negative terminal towards the positive terminal of the direct current source.

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 specification discloses a low loss ballast system for reducing the electrical power required to operate fluorescent and other ionized gas lamps as well as several unique starting and operating circuits which can be used in combination with conventional as well as the low loss system described herein.

Abstract: A high power factor conversion circuit suitable as a ballast circuit for lamps includes a full-wave rectifier coupled to an AC potential source and providing a pulsating DC potential. A high frequency inverter is coupled to a load circuit and to a feedback rectifier circuit supplying a rectified high frequency potential to an energy storage feedback circuit which provides energy in a manner to inhibit a decline in the pulsating DC potential thereby providing a substantially uniform DC potential to the high frequency inverter.

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: 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: A magnetron oscillator, a source circuit for energizing the magnetron oscillator and a fan are contained in independent casing units and the casing units are removably connected together into an integral assembly such that the fan circulates cooling air through the source unit and the magnetron oscillator unit.

Abstract: An A.C. voltage fed power supply for D.C. gas-discharge lamps is disclosed having full-wave rectifying means connected on the A.C. side to at least two phase-adjusting networks for forming mutually phase-shifted partial currents and connected together on the D.C. side to superimpose the rectified, phase-shifted partial currents. Each phase-adjusting network is connected through the full-wave rectifying means to the same load impedance at the two D.C. voltage output terminals.

Abstract: A sinusoidal wave oscillator ballast circuit includes a tuned oscillator coupled to a DC rectifier means coupled by a power factor correction circuit to an AC potential source. The oscillator is coupled to an inductor means including a first and second transformer means with the secondary winding of the first transformer means coupled to the oscillator, the primary of the first transformer means in series connection with a capacitor and the primary winding of the second transformer means to form a resonant circuit, a first secondary winding of the second transformer means coupled to a lamp circuit to form a load circuit shunting the capacitor of the resonant circuit and a second secondary winding of the second transformer means having opposite ends connected by clamping diodes to the DC rectifier means. Means for compensating for "storage time" of the transistor of the oscillator and for conditioning the line to transients and radio frequency interference (RFI) are also provided.

Abstract: A lighting apparatus which provides for high voltage pulses for starting a high pressure sodium lamp. This apparatus uses a zener diode circuit which provides appropriately timed starting pulses even at relatively low line voltage. The apparatus can be designed to supply either one pulse or two pulses per cycle.

Abstract: A relatively infinitely incremental mode of obtaining any desired brightness of flash from an electrically operable flash-tube is attained by employing plural capacitors, each having a charging source of selectable voltage level and a unilaterally conductive element between the capacitor and the flash-tube. The unilaterally conductive element is poled to pass the charge on the associated capacitor during the discharge cycle regardless of the voltage of the charge on other of the plural capacitors involved.

Abstract: Circuit operating from a direct current source applies DC pulses to a high pressure sodium vapor lamp to improve the color rendition of the lamp. The circuit includes a thyristor switch in series with the lamp, an RC timing circuit for periodically turning on the switch at predetermined intervals, and an LC circuit for turning the switch off. An inductor in series with a diode across the capacitor of the LC circuit provides for discharge of the capacitor to enable subsequent re-charging thereof, so as to provide the desired pulsed operation of the circuit. This mode of operation also provides for application of voltage to the lamp which is substantially higher than the supply voltage.

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: 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 a ballast inductor and a lamp across the supply circuit, an SCR switch connected across the inductor, a coasting diode across the inductor and lamp, 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 optimum 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 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: Circuit operating from a direct current source applies DC pulses to a high pressure sodium vapor lamp to improve the color properties of the lamp. The circuit includes a controlled thyristor switch in series with the lamp, an RC timing circuit for periodically turning on the switch at predetermined intervals, and an LC circuit for turning the switch off. An inductor comprising the primary winding of a transformer in series with a diode across the capacitor of the LC circuit provides for discharge of the capacitor to enable subsequent re-charging thereof, so as to produce the desired pulsed operation of the circuit, and the transformer secondary winding in series with a diode clamps the voltage of the primary winding. The disclosed arrangement prevents excessive voltage across the controlled switch and provides for the control of lamp wattage with respect to changes in lamp voltage.

Abstract: Increased color temperature of high pressure sodium vapor discharge lamps is provided by improved operating circuit for applying pulsed direct current to the lamp. The circuit includes a direct current ballast circuit having low ripple factor and a pulsing circuit comprising a controlled thyristor switch which operates to apply DC pulses to the lamp at a predetermined repetition rate and duty cycle. The described circuit provides for gradual increase in power applied to the discharge lamp during the starting interval and thereby avoids instability of lamp operation during that stage.

Abstract: Electrical ballast circuit for operating gaseous discharge lamps with direct current. An inductive reactor coil connected to an alternating current source is connected to a discharge lamp via a full-wave rectifier, and an auxiliary induction coil inductively coupled to the reactor coil is connected to the discharge lamp via another full-wave rectifier, resulting in the currents from the respective rectifiers to the lamp being out of phase with one another, thereby raising the average current through the lamp and the voltage across the lamp to prevent lamp de-ionization and reduce lamp re-ignition voltage. Series connected capacitors may be incorporated in the circuit to increase the starting voltage on the lamp if necessary.

Abstract: Color rendition of high pressure sodium vapor discharge lamps is improved by disclosed operating circuit for applying pulsed direct current to the lamp. The circuit includes a direct current ballast circuit having a low ripple factor, a filter capacitor charged by the output of the ballast circuit, and a pulsing circuit comprising a transistor switch which operates to apply DC pulses on the lamp at a predetermined repetition rate and duty cycle to provide desired color properties of the lamp.

Abstract: A fluorescent lamp ballast circuit includes a tuned oscillator coupled to a pulsed DC potential source and to a transformer having a first winding directly connected to the oscillator and in series connection with a capacitor to form a series resonant circuit. A second winding of the transformer inductively couples the first winding of the transformer to the oscillator, a third winding inductively couples a load across the capacitor of the series resonant circuit, and a fourth winding is inductively coupled to the first winding of the transformer and clamps the DC potential source to a given potential level. Also, protection for open circuits, short circuits, and temperature change due to changed ambient conditions or increased current flow is provided.

Abstract: A single phase, high frequency chopper ballast without large magnetic and capacitive components for gaseous discharge lamps such as the Lucalox.sup.R lamp is operated on full wave rectified line voltage. A small auxiliary capacitor stores energy during the peaks of the rectified line voltage when the voltage is high enough to maintain lamp discharge. During the low voltage valley regions the auxiliary capacitor is discharged to supply augmented chopper input voltage or load circuit voltage and provide energy to maintain lamp ionization during the valley regions until the rectified line voltage rises to a usable level.

Abstract: A method of energizing a laser source stimulating flash lamp directly from an AC power line. Uncontrolled diodes couple the anode and cathode of the flash lamp directly to the AC line. The lamp is triggered by a separate triggering circuit which produces its trigger pulse at a predetermined phase of the AC power source. The use of high current carrying controlled rectifiers and large energy storage devices is thereby eliminated.

Abstract: A device for starting a discharge lamp by means of a transistor starter provided with an auxiliary transistor for stopping the starting procedure if the lamp fails to ignite.A zener diode is included in the control circuit of the auxiliary transistor, a capacitor is connected in parallel across the lamp, and a self-inductor is included in the connection from the lamp to the main transistor. The auxiliary transistor has a second function in that, by the action of the zener diode, the auxiliary transistor delays the conduction of the main transistor so that a large rise of the voltage between the lamp electrodes is produced, which provides a more reliable ignition of the lamp within a large temperature range.

Abstract: A system for controlling power applied to a gas discharge lamp by an AC source, wherein the power dissipated in the lamp during a half cycle is sensed by a measuring circuit. The measuring circuit provides output signals proportional to the current through and voltage across the lamp during its conduction. The measuring circuit output signals are multiplied and the difference between the resultant multiplier signal and a reference signal is time integrated and fed to a pulse width modulator. The pulse width modulator provides a pulse to a pulse transformer to trigger an SCR in series with the lamp at some point in the next half cycle, the point at which the SCR is triggered being determined by the power dissipated in the lamp in the previous half cycle. In another embodiment the SCR is replaced by a transistor and the pulse width modulator shuts off the transistor after the lamp has dissipated the desired amount of power in a given half cycle.

Abstract: A discharge lamp for connection to an associated alternating current power supply. The lamp is provided with two main electrodes and a starting electrode. Two diodes are connected in series, in cathode to anode relationship, between one associated AC power conductor and the starting electrode. In parallel with the diodes is a first capacitor. Connected to the junction between the diodes is a second capacitor which is connected on the other side thereof to a conductor from the other AC power conductor to the main lamp electrode remote from the starting electrode. In operation the second capacitor substantially changes its capacitance responsive to the temperature present with the lamp to effectively make the voltage doubler inoperative.

Abstract: An improved method of and apparatus for operating an electric discharge lamp which includes a controlled semiconductor switch connected in shunt with the lamp. By means of the semiconductor switch, the discharge lamp receives, when in operation, a plurality of voltage peaks, during every second half cycle of the AC supply voltage.

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: A push-pull ballast for an arc discharge lamp has a high power portion comprising a semiconductor switching inverter and transformer means for step-up or step-down of voltage to be supplied to a load and a low power portion comprising control means sensitive to load parameters as, for example, load current which provides instantaneous control over the switching inverter thereby providing the advantages of high input power factor and precise control over the load voltage and current characteristics.

Abstract: A ballast circuit for coupling a lamp to an AC power source and having in series between the source and lamp a non-dissipative current limiting capacitor feeding a rectifier, the output of the rectifier being connected to a smoothing filter. The ballast lends itself particularly to use in connection with a dimmer control, and permits the use of a secondary path or bypass around the dimmer control through another capacitor feeding a rectifier formed as a diode bridge, thereby providing a minimum current level path to the lamp.

Abstract: A power supply for an ac metal halide lamp employs a dc regulator in conjunction with a commutator for supplying the regulated dc power to the lamp with alternating polarity. A feedback circuit senses the dc voltage and current fed to the commutator and cooperates with the regulator to provide substantially constant power to the lamp. The commutator switching times are sufficiently rapid so that flickerless light output is obtained.

Abstract: A solid state starter apparatus for a discharge lamp comprises a current limiter, an AC power supply, a discharge lamp of filament-preheating type and a switching circuit for controlling the turning on and off of the discharge lamp. The switching circuit further includes a lightedstate detector circuit for detecting the turning on or off of the discharge lamp, a current breaker circuit controlled by the lighted-state detector circuit to cause the filament current to be turned on and off, and a preheater circuit for starting to supply a filament preheating current in accordance with the magnitude of the current controlled by the current breaker circuit.

Abstract: A channel number display device for a television receiver for displaying the numerals of the channel to which the receiver is tuned with the display being initially bright immediately after a channel change, and then after a predetermined time of several seconds, being reduced in brightness so as not to distract from the program material. Through the use of a thyristor, regardless of the number of individual elements in the numerical display, the brightness levels may be held to predetermined quantities.BACKGROUND OF THE INVENTIONOver the years, it has been a desire of television manufacturers to provide a display of the channel numbers on the television receiver so that they can be easily read, especially immediately after tuning to a new station so that the viewer can determine if he is at the desired station. This is especially true for television receivers having remote control, wherein the viewer is spaced at the viewing distance from the receiver while tuning to a new station.

Abstract: A starting device for a gas discharge lamp, to whose electrodes AC voltage is applied, comprises:A. first means electrically connected with at least one lamp electrode to apply to the lamp a transient voltage pulse which initially changes in amplitude in a polarity direction relatively in opposition to the polarity of the main voltage simultaneously supplied to the electrodes,B. said first means including circuitry to cause said pulse to thereafter change in amplitude in a polarity direction in aid of the polarity of the main voltage simultaneously supplied to the electrodes.

Abstract: An electrical circuit for limiting surge currents through incandescent indicator or display lamps is disclosed. It is essentially a constant current device having a current controlling transistor in the load circuit to limit the initial surge current to a first value after, which the lamp itself limits the current. Provision is made for testing of the lamp and circuit by maintenance personnel.