Abstract: A dielectric filter includes a plurality of dielectric resonators. The dielectric filter further includes a plurality of resonator bodies corresponding to the plurality of dielectric resonators, and a peripheral dielectric portion lying around the plurality of resonator bodies. Each of the plurality of resonator bodies is formed of a first dielectric having a first relative permittivity. The peripheral dielectric portion is formed of a second dielectric having a second relative permittivity lower than the first relative permittivity. Each of the plurality of resonator bodies includes a plurality of individual elements separated from each other.

Abstract: An electromagnetic relay includes a fixed contact part, a movable contact part, an armature, an electromagnet, and a base. The fixed contact part includes a fixed contact. The movable contact part includes a movable contact that faces the fixed contact. The armature is formed of a magnetic material and configured to bring the movable contact into or out of contact with the fixed contact. The electromagnet is configured to generate a magnetic field to move the armature. The base holds the fixed contact part, the movable contact part, and the electromagnet. The electromagnetic relay further includes multiple electrodes configured to generate an electric field between the electrodes.

Abstract: Photographic lighting devices, systems, and methods having a plurality of electrical energy storage/discharge (EESD) elements and/or one or more light sources in a single photographic lighting device to perform one or more photographic lighting effects. EESD elements and one or more light sources can be configured to have multiple separate light emissions occur in a single image acquisition window. The multiple light emissions are separated in an image acquisition window by a time period that is about shutter speed exposure time/(N?1), where N is the number of light emissions. In one such example, two light emissions are separated by a time period that is about shutter speed exposure time/(N?1).

Abstract: In an example, a method of operating an ultraviolet (UV) light source includes providing a supply power to the UV light source, and activating, using the supply power, the UV light source to emit UV light during a series of activation cycles. The method also includes, during at least one activation cycle in the series, sensing the UV light emitted by the UV light source to measure an optical parameter of the UV light. The optical parameter is related to an antimicrobial efficacy of the UV light. The method further includes adjusting, based on the measured optical parameter, an electrical parameter of the supply power to maintain a target antimicrobial efficacy of the UV light over the series of activation cycles.

Abstract: An illuminated vehicular sign is provided including a vehicle and luminescent planar sheet. The luminescent planar sheet is constructed to provide illuminated alpha-numeric characters which are mounted to the horizontal planar surfaces of a vehicle. The alpha-numeric characters are mounted substantially horizontally so as to be seen from the air such as by helicopters or planes. The illuminated vehicle sign includes a switching system electrically connected to the luminescent planar panels for selectively controlling the transfer of power from said power source to the luminescent planar panels. The switching system including one or more adjustable variable resistors electrically connected to the luminescent planar panels for allowing one to selectively adjust the wattage provided to them.

Abstract: An electrical device includes a core structure having a first core section, a second core section, and a third core section. The electrical device further includes a first coil electrically coupled to the first core section and the second core section to form a choke and a primary winding of a transformer. The choke is configured to reduce common mode noise for an electrical signal received by the electrical device, and the primary winding of the transformer is configured to induce a magnetic field on the third core section. The electrical device also includes a second coil electrically coupled to the third core section, which forms a secondary winding of the transformer and receives electromagnetic energy from the magnetic field induced by the primary winding of the transformer.

Abstract: A circuit component that is adjustable at run time and a method of designing the circuit are disclosed. The component contains a hierarchy of recursive levels in which a bottom level is a compound element made from two connected simple elements, and each higher level contains two compound elements connected in the same fashion. The described circuit allows for a large number of available values of the component value to be arranged in a logarithmic fashion rather than a linear one as in the prior art, thus generally reducing errors between any desired value for the component and the available values. In addition, such compound elements reduce the power dissipated by the analog element and the susceptibility to noise as compared to prior art adjustable components without adversely affecting the overall gain of the circuit.

Abstract: A heating device includes a rotating member that rotates, and plural unit circuits that are aligned in a width direction of the rotating member. The plural unit circuits each includes a heating body that heats the rotating member, a resistive element that is connected in series to the heating body and has a positive temperature coefficient, and a parallel circuit that is connected in parallel to the resistive element. The unit circuits are each configured such that, if a resistance value of the resistive element is increased with a rise of temperature of the resistive element, a current flows through the parallel circuit.

Abstract: A display apparatus includes a display panel, a gate driver, a data driver and a coupling voltage generator. The display panel includes a plurality of pixels. The gate driver provides a gate signal to the display panel. The data driver provides a data voltage to the display panel. The coupling voltage generator provides a coupling voltage to the display panel. The coupling voltage has a plurality of levels.

Abstract: In various embodiments, an electric lamp includes a light source having at least two supply lines configured to supply electrical energy to the light source, and an outer bulb surrounding the light source. The outer bulb is filled with inert gas. The lamp further includes a disconnection mechanism arranged within the outer bulb. At least one of the supply lines is interrupted in the event that the disconnection mechanism is tripped. The disconnection mechanism has a switch.

Abstract: A replaceable fluorescent lamp starter unit of a fluorescent light fixture has a built-in RF transceiver, and communicates wirelessly with a motion-detecting master unit. The starter unit can be controlled to turn off and turn on the fluorescent lamp of the fixture. The starter unit is registered to the master unit so that the starter unit will not respond to wireless communications from other sources. During registration, registration information is loaded into the starter unit and stored in non-volatile memory. The stored registration information is later usable to determine whether subsequently received wireless communications are for the starter unit. Systems of existing light fixtures are retrofitted with such wireless starter units, and thereby made controllable by a master unit so that the master unit can turn off the lights to conserve energy if room occupancy is not detected. The master unit can control lamp fixtures individually or as a group.

Abstract: A method and apparatus for reducing unwanted radiation from a light fixture have been disclosed.

Abstract: When performing gradation expression using a time division driving method, an operational frequency of a driving circuit is suppressed, and non-light emitting time is eliminated to increase the light emitting time. Each of a number of pixel circuits includes a light emitting element, a driver element for turning on or off a driving current of the light emitting element, a switching element for controlling connection of a gate electrode of the driver element with a signal line, and a capacitance to which a signal voltage supplied from the signal line to the gate electrode of the driver element is written.

Abstract: A control circuit for use in an active matrix organic light emitting diode (AMOLED) panel comprising a memory unit and a voltage control unit is provided. The operating time of the AMOLED panel is counted and saved by the memory unit. According to the memory unit's information, the voltage control unit decides a common voltage. The purpose of the present invention is to reduce the common voltage when the turn-on time of the AMOLED panel is increased so that the increase in the voltage difference between the two terminals of an organic light emitting diode (OLED) of the AMOLED panel may be compensated. Thus, the present invention may provide a stable driving current for the OLED and a stable picture definition for the AMOLED panel.

Abstract: The present invention relates to glow-switch starters 1, lighting devices therewith and use thereof. The glow-switch starter 1 is suitable for use with three phase supply voltages substantially higher than the common 230V supply voltage 26. This allows more efficient gas discharges in e.g. fluorescent lamps 20, and/or more lamp power, and/or less energy losses in ballasts 22 and lamp electrodes. To make the glow-switch starter suited for such use, according to the invention, the gas filling 5 of the starter 1 is adapted. An important criterion is that the glow current in the steady state operation of the fluorescent lamp that is started by the starter is small enough to prevent closing of the (bimetallic) switch.

Abstract: Disclosed is a starter for AC-fed low-pressure discharge lamps that are operated on a series inductor. The starter comprises a glow fuse, a high-temperature conductor (NTC resistor) that is serially connected to the glow fuse, and a resetting bimetal switch which is serially connected to the glow fuse and the high-temperature conductor and is in thermal contact therewith. The high-temperature conductor is provided with high resistance in a cold state, which is transformed into low resistance by elements of built-up heat while the bimetal switch interrupts the electrode heating circuit when the low-pressure discharge lamp fails to ignite. According to the invention, the current is conducted via the high-temperature conductor for both igniting the low-pressure discharge lamp and switching off when the discharge lamp fails to ignite.

Abstract: The present invention provides methods, apparatus and systems for enabling real-time lighting of 3D geometric models. While these are well-suited for all processors, these are particularly useful on low power processors typically found in PDAs, cell phones, and embedded display systems. Methods+presented utilize a preprocessing scale factor and real-time shift factor to efficiently calculate diffuse lighting intensities for the bound vertices of the geometric model. An example embodiment includes scaling first digitized data of a 3D model in a floating point datatype by a scaling factor to form scaled digitized data. The scaling factor being a proper power of two. Converting said scaled digitized data into an integer datatype forming second digitized data. Enabling a transfer of said second digitized data to a display system, and facilitating lighting and shading said second format of digitized data.

Abstract: An operation voltage auto-adjustable circuit for active matrix organic light emitting diode (“AMOLED”) and an auto-adjusting method thereof is provided. The circuit for automatically adjusting a operation voltage of an AMOLED includes a display panel of an AMOLED having a terminal of an organic light emitting diode (“OLED”); and an auto-adjusting circuit connected to the terminal of the OLED, wherein a current passing through the terminal of the OLED is detected by the auto-adjusting circuit, and a voltage applied to the terminal of the OLED is adjusted by the auto-adjusting circuit according to the current detected. Therefore the current passing through the terminal of the OLED is sensed to automatically adjust the voltage applied thereto, and the current passing through the terminal of the OLED is stably maintained.

Abstract: An arrangement and method are provided to avail information visible at an observation location is provided. The arrangement includes a sensor adapted to sense at least one process parameter and a display for providing a visual representation of the at least one process parameter received from the sensor. The sensor can be electrically limited by an intrinsically safe barrier, and is capable of being powered in accordance with a fieldbus protocol. The display is electrically limited by an intrinsically safe barrier, and is capable of being powered in accordance with the fieldbus protocol. The display may include a light producing device for generating light and an intermediary (or light blocking) layer. The intermediary layer can be positioned closer to the observation location than the light producing device, and may be configured to selectively block or reduce the intensity of a portion of the light generated by the light producing device.

Abstract: A dielectric waveguide tube band-pass filter assuming lower characteristic change upon mounting, and having smaller dimensions and lower loss. Conductor layers (2a, 2c) are formed on the top and bottom surfaces of a dielectric substrate (1), wherein the top conductor layer 2a and the bottom conductor layer 2c are connected together through via-holes (3a). The via-holes (3a) are formed in at least two rows along the signal transfer direction. In the dielectric waveguide tube configured by the top and bottom conductor layers (2a, 2c) and the via-holes (3a), via-holes (3b) are arranged in the signal transfer direction at spacing equal to or below ½ of the in-tube wavelength to thereby configure resonators. The dielectric band-pass filter is configured by coupling adjacent resonators together through the via-holes (3b) configuring inductive windows.

Abstract: A method for thermal control of a lamp assembly which includes an arc lamp, fan and an associated reflector enclosed within a sealed module. The method includes providing a predetermined air flow path within said module whereby a continuous flow of ambient air is passed over said lamp during lamp operation which reduces the operating temperature of the lamp and increases lamp life, and further including an opening or vent adjacent to the fan which functions to reduce the fan temperature in operation thereby increasing the operating life of the fan.

Abstract: A LED driver is disclosed. The LED driver includes a high frequency inverter and an impedance circuit. The high frequency inverter operates to produce a high frequency voltage source whereby the impedance circuit directs a flow of alternating current through a LED array including one or more anti-parallel LED pairs, one or more anti-parallel LED strings, and/or one or more anti-parallel LED matrixes. A transistor can be employed to divert the flow of the alternating current from the LED array, or to vary the flow of the alternating current through LED array.

Abstract: A flasher string which includes a plurality of flashers connected in series and a plurality of thyrsitor diodes, each thyrsitor diode connected to a respective flasher in parallel. The flasher can periodically turn on and off to produce a twinkling light due to thermal distortion of the metal piece in the flasher. When the flasher turns on, the metal piece normally contacting the filament of the flasher is heated to expand and then escapes from the filament so as to turn off the flasher. Sequentially, the metal piece is cooled down to shrink back the original shape and contacts the filament to turn on the flasher again. The respective thyristor diode in parallel with the flasher is used to sustain the current when the flasher is off so as to minimize the impact of abrupt current change on the flasher string for a longer lifetime.

Abstract: A start circuit (1) includes a series connection of a glow switch (10) and a safety switch (12), which are each provided with an enclosed space (10a, 12a), with a pair of current conductors (10b, 10c resp. 12b, 12c) which enter the enclosed space and with a bimetallic element (10e resp. 12e) which is arranged in the enclosed space and which is connected with one (10c resp. 12c) of the current supply connectors. The enclosed space (10a) of the glow switch (10) is provided with an ionisable filling. The glow switch (10) is opened in cold state. The safety switch is closed in cold state. The start circuit (1) comprises a heat source (11) for opening the safety switch (12). The start circuit further comprises a heat source for keeping the safety switch (12) open which is formed by an ionisable filling in the enclosed space (12a) of the safety switch (12).

Abstract: An annulus fluorescent lamp comprises two annulus fluorescent tubes formed into shapes having different diameters and disposed substantially concentrically in substantially the same plane. Each of the annulus fluorescent tubes has a first end with an electrode seal portion and a second end without electrodes. The second ends of the annulus fluorescent tubes are communicated with each other via a bridge portion so that a single discharge path is formed inside the plurality of annulus fluorescent tubes. The annulus fluorescent lamp also comprises a mouthpiece covering the first and second ends of the annulus fluorescent tubes, and a thermal fuse disposed in the mouthpiece and close to the electrode seal portion of the annulus fluorescent tubes. The thermal fuse is connected electrically between one of outer lead wires of the electrodes and one of lead terminals fixed to the mouthpiece.

Abstract: A circuit arrangement for operating a discharge lamp comprising input terminals for connection to a supply voltage source. A load branch B has terminals for holding the discharge lamp and includes an inductive ballast. A device I is coupled to ends of the load branch and to the input terminals to generate a high-frequency voltage from the supply voltage furnished by the supply voltage source. A device II is coupled to the device I to adjust the power consumed by the discharge lamp, the frequency of the high-frequency voltage being dependent upon the adjusted value of the power consumption. A transformer having a primary winding and secondary windings with each secondary winding shunted by an electrode branch during lamp operation, which electrode branch includes an electrode of the discharge lamp. The primary winding forms part of a branch C which also includes a frequency-dependent impedance and which shunts the load branch.

Abstract: A fluorescent lighting control system providing automatic and/or manual adjustability of the arc current(s) in one or more fluorescent lamps to permit operation of the lamps at less than rated wattage, and its concomitant luminous flux, in interior building spaces where full light output of the installed lamp(s) is rarely required particularly when daylight components are present. The goal(s) of this invention is to provide means to reduce wasteful electrical consumption in buildings and thereby reduce operating costs and gain the attendant benefit of dampening the increasing need for more electrical generation with its concomitant environmental pollution problem.

Abstract: A fluorescent lamp starter circuit includes a relay which forms a first circuit loop to detect the input voltage and to switch the relay from the normally-closed position to the normally-open position once the input voltage reaches the threshold level. The switching of the relay to the normally-open position opens the first circuit loop and closes a second circuit loop constituted partly by the relay to allow current to flow through and heat up the electrodes of the fluorescent lamp. After a certain time period, the relay, which is controlled by the discharging of a capacitor, is switched back to the normally-closed position to open the second circuit loop. The electrodes of the fluorescent lamp, after having been heated, begins to emit electrons and this lowers down the impedance that it represents so that the voltage across the first circuit loop is not sufficient to actuate the relay so as to maintain the relay at the normally-closed position.

Abstract: A rapid start fluorescent lamp having an improved hot restarting time. The lamp includes the standard envelope and end cap through which electrical connection is made by conductive feedthroughs which extend through the lamp stem to the interior of the lamp. One of the feedthroughs is connected to the cathode, and the other is connected to the leads of a fuse element which is contained within an envelope to isolate the fusible element from the lamp environment. A thermally activated bimetallic element is disposed across the leads of the fuse. The other lead of the fusible element is connected to the other end of the cathode. When the bimetal element is cold, it will bridge the connection between the other feedthrough to the other end of the cathode to permit rapid starting. When the bimetal heats up, the connection of both ends of the cathode to the heating current is broken. The location of the bimetallic element within the lamp envelope but not in the fuse container permits it to open and close more rapidly.

Abstract: A thermal-switch instant starter for a fluorescent light which initiates a high voltage instantly across its electrodes comprises a high voltage initiating tube including therein a fixed electrode and a movable electrode oppositely spaced from each other to form a short circuit for initiating the fluorescent light. The movable electrode is a thermal switch constantly disposed in contact with a heater element which is disposed on the fixed electrode. An SCR automatic charging and discharging circuit is connected between the fixed and movable movable electrodes and automatically control the charging and discharging process.

Abstract: A fluorescent lamp unit comprising a self-contained assembly intended for use in replacement for a conventional incandescent filament lamp comprises two U-shaped fluorescent tubes (54, 55), each provided with filaments (56, 57) at respective ends of the arc discharge path. Lead-in wires (60, 68, 69, 76) are arranged to connect the separate arc discharge paths of the two fluorescent tubes in series, and remaining lead-in wires (61, 70, 67, 73) of the fluorescent tubes are connected to components of a starter circuit housed within the mounting (20, 22) of the lamp unit. The starter circuit preferably comprises a separate glow bottle switch (62, 71) for each fluorescent tube, and a single capacitor (65).

Abstract: A modified impedance rapid start fluorescent lamp system is provided with interrupted cathode heating. This structure includes a circuit in parallel with one of the bimetal switches at each side of a cathode. The circuit includes a current limiting capacitor and bleeder resistor connected in parallel with each other and a third normally closed thermal bimetal switch.

Abstract: For the operation of warm start gas discharge lamps upon employment of an electronic ballast wherein the gas discharge lamp lies parallel to the effective capacitance of a series-resonant circuit and has its heater coils incorporated into this series-resonant circuit. An isolating switch is provided in series with the effective capacitance. This isolating switch interrupts the shunt to the lamp and, thus, the heater coil current as well, as soon as the lamp has ignited. It is assured in this way that the current flowing in the shunt to the lamp which otherwise represents a dissipated power is suppressed. Particular significance is accorded to this method when the effective capacitance of the series-resonant circuit is executed variably during the starting interval phase with the assistance of temperature-dependent resistors or is executed with time delayed electronic switches for the control of the lamp voltage.

Abstract: A fluorescent lamp electrode heat cutout switch is provided for placement within a fluorescent lamp stem and outside the discharge envelope and is configured such that a resistive heater wire is connected to one electrode lead-in and a bimetallic switch element is connected to the other electrode lead-in and configured upon an insulating support in such fashion that the heat cutout switch receives heat from the resistive heater to activate the switch so that the electrode heat is cut off when the lamp starts and is kept off during normal lamp operation.

Abstract: A circular fluorescent lamp assembly having the entire ballasting circuit, along with a thermal protector, contained within the assembly's lamp holder. The thermal protector serves the dual function of preventing permanent damage to the assembly's ballast means and for extending lamp starting switch means operating life under normal end of lamp life cycling conditions. The thermal protector is responsive to the coil temperature of the ballast means and is electrically coupled in series with the ballast means, starting switch, capacitor and the lamp. One example of the thermal protector is a bimetal bottle switch.

Abstract: To provide for reliable ignition of low-pressure discharge lamps, particularly compact fluorescent lamps, operated at high frequency, for example in the order of about 45 kHz, an ignition circuit is connected in parallel to the lamp and serially with the electrodes (16, 17) thereof, which comprises a limiting capacitor (19) and the parallel circuit of a positive temperature coefficient (PTC) resistor (20) and a starting capacitor (18). The two capacitors (18, 19), together with an inductance (13, 14) in the operating circuit of the lamp, and a further capacity formed by a blocking capacitor (15), after preheating of the lamp electrodes by current flowing through the initially cold PTC resistor, will cause voltage rise across the resonance capacitors (18, 19) which will cause ignition of the lamp.

Abstract: An electrical device for igniting and supplying a low-pressure mercury vapor discharge lamp (11) provided with two preheatable electrodes (12,13). A series arrangement (12, 4, 14, 13) comprising the two lamp electrodes (12, 13), a PTC resistor (14) and a second winding (4) of a transformer fed back negatively with respect to a first winding (3) thereof is connected to a connection point of the first transforming winding. This series arrangement (12, 4, 14, 13) is further connected to a second connection point of the first transformer winding (3). Thus, the electrical device will readily ignite and supply the lamp and will also protect the PTC resistor of the electrical device should the lamp fail to ignite even with lamp electrodes that are uninterrupted.

Abstract: A ballast circuit for starting and operating a preheat type circular fluorescent lamp, which replaces a multiple wattage incandescent lamp in a three-way incandescent lamp socket, so that the fluorescent lamp can be ignited to function at three different operating wattages. A lamination stacked core structure mounts first and second coils. A passive circuit element, such as positive temperature coefficient resistor also known as a thermistor, is connected in the circuit, which includes a three-way incandescent lamp screw base, for current switching functions to achieve the desired ignition and operating currents for the fluorescent lamp at its different operating wattages.

Abstract: In a metal vapor discharge lamp for operating it by high voltage generated in the actuation of a heat sensitive switch means in an outer bulb, a relatively low pressure of a sealed gas or mercury is sealed in the outer bulb to operate the heat sensitive switch means in the gas atmosphere to control the surge voltage to a desired degree whereby the discharge lamp is operated without failure and the insulation breakdown of a ballast and an operation circuit is prevented.

Abstract: A discharge lamp starting device employing a thermal switch which comprises main and auxiliary bimetal electrodes respectively thermally bendable in the same direction, and an auxiliary heater for heating the auxiliary bimetal electrode in addition to a main heater for the main bimetal electrode. The auxiliary heater is energized to heat the auxiliary electrode upon a starting failure specifically when the discharge lamp is to be lighted again immediately after its extinguishment, whereby the auxiliary electrode is forced to bend toward the main electrode and a re-closing of the thermal switch and eventual lamp starting can be accelerated.

Abstract: A multiple fluorescent lamp ballast circuit of the rapid start type in which heating current is supplied to the lamp cathodes. A time delay switch is connected in series with a starting capacitor across one or more of the lamps, to delay lamp starting until the cathodes are sufficiently heated.

Abstract: A screw-in fluorescent light unit having two light levels, for use in a 3-way socket. A reactor ballasts the lamp for high light output, and a positive temperature coefficient resistor (thermistor) is added to ballast the lamp for low light output and to facilitate lamp starting at the low light output. The light-level sequence is off-high-low-high-off.

Abstract: A screw-in fluorescent light unit having two light levels, for use in a 3-way socket. A reactor ballasts the lamp for high light output, and a resistor is added to ballast the lamp for low light output. A bilateral switch device is connected across the resistor to facilitate lamp starting at the low light output.

Abstract: A screw-in fluorescent light unit having high and low light levels, for use in a 3-way socket. A reactor ballasts the lamp for high light output, and a variable dimming circuit is added to ballast the lamp for variable low light output.

Abstract: A metal vapor discharge lamp comprises main electrodes and an auxiliary electrode in an arc tube to initiate the discharge between the main electrode and the auxiliary electrode at the initiation of the operation and then to result the discharge between the main electrodes by disconnection of the auxiliary electrode by a bimetallic switch means. A second bimetallic switch means which delays the operation from that of the first bimetal, is connected in series to the first bimetallic switch means so as to discharge in a circuit formed in an outer bulb to break a part of the circuit and to prevent a ballast from overheating.

Abstract: A high intensity discharge lamp comprises a two-electrode arc tube and an external starting probe supported from a base and preferably sealed within an outer envelope to which the base is attached. The base contains an electronic pulsing circuit comprising a capacitor connected in a charging circuit across the base terminals, a pulse transformer having its primary connected in series with a voltage sensitive switch across the capacitor, and a step-up secondary connected to the probe. After starting, the voltage across the capacitor drops below the breakdown level of the switch and pulsing stops.

Abstract: A lamp assembly (10) comprises a base plate (12) having both an incandescent bulb (18) and a fluorescent bulb (16) affixed thereto. The incandescent bulb (18) acts as ballast and light source. A glow switch (26) and capacitor (27) act as starter and are contained within the base plate (12) or socket means (14). A starting aid (24) is impedance coupled into the series filament network.

Abstract: Methods and apparatus for electronically igniting gas discharge lamps, such as hot- or cold-cathode fluorescent lamps, various high-pressure, metal-gas, and halogen-gas lamps.The initial heater current, in the case of hot-cathode lamps, or the initial high voltage across the unignited lamp, in the case of cold-cathode lamps, is used to heat a positive temperature coefficient resistor. The heat generated by this resistor causes a striker mechanism, consisting in essence of a pre-tensioned bi-metal disc or strip, to buckle, the said buckling striking a piezo-electric crystal, thereby inducing a high voltage, which ignites the lamp.Various coupling circuits between the mechanism and the lamp are described.The important features, compared to presently known igniters relate to the flickerless and reliable ignition of the lamp, more reliable igniter structure, and lengthened life time of the lamps.

Abstract: An inductive stabilization ballast for a low-pressure mercury vapor discharge lamp having preheatable electrodes. The ballast includes a protective device which comprises a positive temperature coefficient resistor. The inductive portion of the ballast and the PTC resistor are disposed in the ballast so as to be insulated relative to one another, both electrically and thermally. The PTC resistor is connected in series with a glow starter in the preheating circuit of the lamp electrodes. Thus, the electric current in the case of a non-starting lamp is kept at a harmless low level and, in the case of a normally operating lamp the PTC resistor does not disturb the lamp operation.

Abstract: A multi-lamps LCD back-light control circuit comprises a control unit, an full bridge switch, a resonance network circuit, a voltage transformer, a lamp, and a feedback network. A constant operating frequency and a pulse width modulation (PWM) feedback are used to control the CCFL current. The back-light control circuit is such that a power switch of the full bridge switch outputs a duty cycle that is controlled and changed via a PWM controller of the control unit, while a ground switch of the full bridge switch outputs a constant duty cycle controllable above 50%.