Abstract: A method (100) of controlling an inverter in an electronic ballast for at least one gas discharge lamp protects the inverter from damage due to lamp fault conditions, and provides enhanced noise immunity and multiple ignition attempts for low-temperature lamp starting. The method (100) includes repeating a filament preheating step and a frequency shifting step up to a predetermined number of times in order to facilitate lamp ignition under low-temperature conditions and to verify the legitimacy of a detected lamp fault.

Abstract: A photocell device for use with an exterior landscape lighting assembly. The lighting assembly includes a transformer having an input line connected to an electrical power source. The transformer converts a primary electrical voltage to a secondary electrical voltage which is in turn outputted through an output line connecting to a plurality of individual lighting units. The photocell device includes a turf stake capable of engaging into a ground location. An enclosure is mounted atop the turf stake and includes a power supply circuit, a photo sensor and control circuitry communicating with the photo sensor. The power supply circuit converts the secondary transformer output to an unregulated and filtered direct current suitable for powering the control circuitry. The control circuitry interfaces with the photo sensor and, in response thereto, selectively activates and deactivates the plurality of lighting elements.

Abstract: A high pressure sodium discharge lamp includes first and second discharge devices electrically connected in series within an outer envelope. The discharge devices each include a discharge vessel enclosing a discharge space with an ionizable fill and first and second discharge electrode assemblies. The first discharge electrode assemblies of the discharge devices are connected so as to receive a starting pulse and lamp operating voltage. Each discharge vessel includes a first wall portion spaced from the first discharge electrode assembly and defining an ionizable gap therebetween. A conductive element bridges the discharge devices at the first wall portions and capacitively couples the first discharge electrode assemblies to induce ionization in one of the discharge devices in the ionizable gap between the first wall portion and first discharge electrode assembly.

Abstract: A two-wire display lighting control structure mainly including a main driver outputting pilot control signals and a plurality of sub-drivers each containing a signal discriminator and a load making circuit and each having a flood light or a light string serially connected thereto. A two-wire conductor is sufficient for use between the main driver and the sub-drivers to serially connect them. The pilot control signals output by the main driver replace first half-cycles of sine waves of an alternating current for supplying power needed by the sub-drivers and individually controlling series-parallel connected flood lights or light strings, so that the flood light or light string connected to a selected sub-driver lightens when it is supplied with power from another half-cycles of the sine waves of the alternating current.

Abstract: Electronic lighting devices that simulate a realistic flame are disclosed. The preferred embodiment has a plurality of lighting elements in a plurality of colors which are modulated in intensity by a control circuit with a stored program. The control program includes stored amplitude waveforms for the generation of a realistic flame simulation. The program further contains random elements to keep the flame constantly changing. The control circuit has built in power management functions that can control the mean intensity of the simulated flame based on some power management budget with the ability to measure the charge/discharge duration of the power source, when used with a rechargeable power source. The currents to the individual lighting elements are selectable from a set of discrete quantization values. Tables of amplitude modulated time waveforms are stored in the microprocessor memory, from which the real time control data streams for the individual lighting elements are synthesized.

Abstract: A system for providing one-step dimming of indicator lights in an illuminating indicating device while allowing adjustable control of the general illumination of the device. The system includes a first current drain (176) coupled to an indicator light source (32-42) for drawing a first current through the indicator light source. A second current drain (186), controlled by control circuitry (198), couples to the indicator light source (32-42) for selectively drawing additional current through the indicator light source (32-42). In a preferred embodiment, the first current drain (176) couples to the second current drain (186) to regulate the additional current draw by the second current drain (186). Preferably, the control circuitry (198) is responsive to an illumination signal to prevent the additional current draw during a low ambient light condition. For general illumination of the indicator device (10), an illumination light source (56-60) responsive to the illumination signal may also be included.

Abstract: An illumination apparatus for illuminating paintings at least a part of which is painted by a particular paint that emits or reflects light upon reception of ultraviolet ray, has a first illumination lamp constituted of an ultraviolet lamp and a second illumination lamp constituted of incandescent lamps. The ultraviolet lamp and incandescent lamps are controlled by a control circuit to be repetitively turned on and off as time elapses in accordance with a control sequence selected by an observer. While the incandescent lamps are turned on, the ultraviolet lamp is turned off to make the painting viewed as, e.g., a daytime landscape without showing, e.g., a nighttime landscape, and while the incandescent lamps are turned on, the ultraviolet lamp is turned on to make the same painting viewed as the nighttime landscape.

Abstract: A control circuit and ballasting means controls the light output of a gas discharge lamp in response to switches that are external to the ballast. The invention provides 3 levels of light output with single or multiple lamps. One embodiment of the invention can be mounted in a standard three-way socket for incandescent lamps. Another embodiment can be used to control multiple lamps in a ceiling-mounted fixture, replacing an inboard/outboard configured multiple ballast circuit. Other embodiments provide circuits that allow conventional dimming ballasts which are designed to be controlled with a low-voltage DC input signal to be controlled by a pair of switches connected to an AC power source.

Abstract: A low cost power supply with enhanced safety protection for neon lamps connected in a midpoint commoned lamp configuration. The power supply has a return path which is isolated from the earth ground so that a fault current does not flow from the output terminals to the earth ground. The windings are phased in a series opposing configuration such that the voltages between the output terminals sum to zero. This power supply of mid-point connected secondary coil design is capable of operating lamp lengths that typically require 15,000 volts of open circuit voltage while not exceeding 7500 volts to ground when any one output terminal is grounded.

Abstract: A circuit for protecting fluorescent lamps connected to a high frequency electronic ballast has a detecting bridge connected to the fluorescent lamps, an output of the detecting bridge varying linearly with a difference between a highest and a lowest voltage across the fluorescent lamps. A timer is connected to the detecting bridge output, and a trigger is connected to an output of the timer, the trigger being responsive to an over-voltage condition of a fluorescent lamp operating at failure mode. A controllable switch is connected across the fluorescent lamps, the controllable switch being controlled by an output of the trigger. The controllable switch, when closed, shorts the fluorescent lamps between their terminals, to protect the circuit when one or more fluorescent lamps are operating at failure mode or at the end of their operating life.

Abstract: A universal input dimming circuit for coupling an isolated external control signal into a variable output power supply, particularly those used for driving fluorescent lamps. Circuitry is incorporated which allows to discriminate between a DC control voltage or a relatively low-frequency pulsewidth-modulated signal using the same pair of input leads. By appropriate conditioning and waveshaping, the circuit produces a pulsewidth-modulated output which is then coupled across an isolation boundary and then demodulated to provide a command signal to the dimming ballast.

Abstract: A device for operating lamps, such as fluorescent lamps includes an input protection circuit, a filter, a DC to DC converter, a power output stage, a lamp connecting circuit and a control circuit. The control circuit includes a pulse width modulator, a multivibrator and a start/stop controller. The pulse width modulator varies the duty cycle of a control signal supplied to the DC to DC converter based on a feedback signal from the DC to DC converter. The multivibrator assists in the control of the DC to DC converter. The start/stop controller initiates the operation of the power output stage when an output of the DC to DC converter reaches a predetermined level and halts the operation of the power output stage if a failure is detected.

Abstract: A circuit arrangement controls power to a fluorescent lamp rather than controlling current. Since light output is proportional to power, flicker control is improved and lamp life is extended.

Abstract: The lighting system for an aircraft cabin includes multiple illuminating units for distribution about a cabin. Each illuminating unit includes at least one variable light source providing light of a known characteristic and that is energizeable independently of other illuminating units. A controller controls energization of the illuminating units by way of dimming and switching units associated respectively with the illuminating units. The controller is operable to create different predetermined combinations of energizations of the illuminating units so that a desired lighting scene is created within the cabin by the energized illuminating units. The controller is arranged to effect a gradual transition to the energizations of the illuminating units when changing from one predetermined combination to another. As a result, there is a corresponding gradual change between scenes created in the cabin.

Abstract: A low-pressure mercury discharge lamp with a lamp vessel having a first lamp vessel portion (La1) with a first electrode (E11) and a first luminescent layer which radiates white light of a first color temperature during lamp operation and a second lamp vessel portion (La2) with a second electrode (E12) and with a second luminescent layer which radiates white light of a second colour temperature different from the first during lamp operation. The first lamp vessel portion and the second lamp vessel portion are interconnected by a connection which allows a filling of mercury and a rare gas in both portions to pass and together enclose a discharge space. The discharge space contains only one further electrode (E13) for both the first and second lamp vessel portions.

Abstract: A lighting control system consisting of microcontroller enabled modular lighting circuits linked by asynchronous serial communication originating in a microprocessor.

Abstract: A circuit for driving a gas discharge lamp load and including an EMI and transient supply filter coupled to an input source, a rectifier coupled to the filter, a power inverter coupled to the rectifier, a load including a transformer coupled to the power inverter, and a control circuit coupled to the power inverter and the load. A feedback circuit couples the load transformer to the AC side of the rectifier to create a path for transferring a feedback voltage over the rectifier to cause the rectifier to conduct current over a substantive portion of each cycle of the AC input voltage.

Abstract: An electronic circuit for converting AC or DC input current to pulsating DC, then to high frequency AC. The DC input is used for aircraft applications, or in emergency situations. The circuit operates over a wide range of input voltages and frequencies, including aircraft 115 volts, 400 Hertz. The circuit has a multivibrator that receives a smooth DC operating potential. The multivibrator is operably connected to a differentiator that produces substantially square waveform outputs. Dual wave shape filters are operably connected to the differentiator to shape the square wave outputs into a sine wave and a cosine wave respectively. A transistor switch is operably connected to each wave shape filter. The circuit has a transformer operably connected between the transistor switches and a load. In a specific embodiment the loads are either hot or cold fluorescent lamps, or the like.

Abstract: A method and device for controlling vehicle interior lighting as a function of certain lighting-relevant states, in which the respective turning-on or turning-off process takes place with dimming. The dimming parameters, such as turning-on or turning-off dimming time or desired final brightness, are selected in advance as a function of the vehicle state that activated the control process, which permits a highly variable and situation-specific lighting control. The lighting control unit, depending on signals from a sensor group and according to a program stored in a program memory, controls a lighting device through a controllable switch.

Abstract: For the demodulation of modulated carrier signals (AS) supplied to the cordless telecommunication apparatus, a data comparator (1212) is used in the cordless information transmission, especially a DECT-specific information transmission, which data comparator is supplied for this purpose with a reference signal (RS) generated by integration of the carrier signal (AS) at an input (E2) for the purpose of demodulating the carrier signal (AS). Since, according to the DECT transmission convention, two identical bit values of a synchronization word (S-BW) must also be detected in addition to the demodulation, a decision threshold (ES) of the reference signal (RS) is changed by an error value (dES). In the cordless telecommunication apparatus, a compensation arrangement (16, 19, 142) which compensates for this error value (dES) is therefore additionally provided.

Abstract: A lighting unit including an illumination element, and an electric circuit comprising electric power supply leads, coupled with the illumination element and operable to deliver electric power to the illumination element for actuation thereof, having an electric fuse integrally coupled to at least one of the leads to provide electrical isolation of the lighting unit in the event of an electrical short therein. The invention has particular utility in application to electroluminescent lamp units, of a type which is usefully employed in assembly of multi-unit electroluminescent lamp arrays. When provided in a parallel circuit arrangement comprising a multiplicity of individually fused lamps on a common power feed, the failure of any one lamp will not cause any other lamp to cease operation.

Abstract: An improved LED lamp construction is disclosed having a plurality of LEDs electrically interconnected and mounted upon opposed rounded surfaces formed at one end of the lamp body. The opposed rounded surfaces comprise a substantially semi-spherical lamp head concavely open at the upper end of the lamp and a cover similar in curvature to the head and fixed across the open end thereof in a convex position relative thereto. The LEDs are arranged in multiple series groups connected in parallel and disposed circumferentially along the rounded surfaces so as to project radially therefrom in substantially all directions. The LEDs are electrically and mechanically connected to a conventional screw-type base at the opposite end of the lamp body through an intermediate stem. Depending upon the nature and level of the power source being provided to the screw-type base, the stem may-house a conventional regulator circuit intended to convert an applied level of A.C. voltage to a relatively low D.C.

Abstract: The load circuits for the different lamps of a 2-lamp ballast are selected to have sufficiently different resonant frequencies so that the luminous fluxes of the two are different when the ballast operating frequency is at one of the resonant frequencies. The ballast is operated at a frequency between those two resonant frequencies. The circuit may include a device for measuring the ratio between the luminous fluxes of the two lamps, and the frequency control circuit is then responsive to that ratio.

Abstract: A light string system includes a plurality of LED's connected in parallel and a regulated power supply for providing a constant current and a constant voltage to the LED's. The light system may be used for decorative, signaling and a variety of other applications.

Abstract: A dimmer for use in lighting control in which a triac control circuit in included which allows for control of both incandescent and low voltage lighting systems at low and high intensities 142,144. The triac control circuit includes a microcontroller 130 which alters the duration of the gate triggering pulse for the triac 134 based upon the desired intensity level of the load. This dimmer is used in a lighting control system and the dimmer is responsive to a system controller 2 as well as to momentary switch inputs which are made directly to the dimmer. The triac control circuit can also be used with other inductive loads.

Abstract: A retrofittable lamp using light emitting diodes as the illumination source, the lamp is fitted with any one of the common lamp bases and is intended as a retrofit for incandescent lamps having such bases in illuminated signs such as exit signs and the like. The invention contemplates the packaging of a number of light emitting diodes in a circuit usually having a current limiting device to allow LED operation at a desired current level. The light emitting diodes are placed within a standard glass or plastic bulb envelope in arrangements capable of providing even illumination from the lamp.

Abstract: A lighting fixture has a lamp and a housing for a lamp ballast. In the new fixture for providing bilevel illumination, the housing also contains a control device comprised of a dual capacitor and a "random crossing" relay connected to the capacitor. A single electrical control wire is attached to the relay and extends from the housing to a control module for remotely controlling the level of illumination consumed by the fixture. In a system employing one or more of the new fixtures, the level of illumination provided by each fixture is controlled by applying a signal to the control wire and switching the relay independently of the instantaneous value of the voltage across the relay terminals. A new method for providing two levels of power to the fixtures (and, thus, two levels of illumination) is also disclosed.

Abstract: A low frequency square wave electronic ballast used for a gas discharge device includes a high power factor pre-regulator connected to a sinusoidal AC power supply and a power controlled DC current source connected to the pre-regulator. A low frequency square wave DC-to-AC inverter is connected to the DC current source and an ignitor circuit is connected to the inverter. A monitor circuit as well as a low power stabilized logic supply voltage source are also employed. The entire circuit is connected to a gas discharge device such that the instantaneous power of this device is constant and controlled providing an acoustic resonance free operation and an ideal ballast curve.

Abstract: A lighting control system which comprises an AC mains power point, power distribution means coupled to the AC mains, a dimmer assembly comprising one or a plurality of co-located dimmer circuits each coupled to the distribution means to receive AC power therefrom, and each comprising an output port developing an AC power signal of frequency corresponding to the AC mains, each said dimmer circuit comprising a current path between the distribution means and the output port, a switching means located in the current path so as to controllably interrupt passage of current, switch driving means supplying a control signal to the switching means to cause it to interrupt the current path a multiplicity of times within each AC half cycle, and filtering means in the current path between the switching means and the output port arranged to smooth the current therethrough, the filtering means being arranged to attenuate current components at the frequency of operation of the switching means, and not substantially to attenu

Abstract: A controlled lighting system comprises a control system which transmits DATA and CLOCK information to a plurality of light modules. The light modules each include at least two light elements and a control unit which is responsive to the DATA and CLOCK information received from the control system to vary individually the amount of light emitted by each of the light elements in each light module. Contemplated uses of the controlled lighting system include decorative lighting, illuminated display signs, etc.

Abstract: A cordless lighting system for a Christmas tree comprising a control transmitter for generating light signals of first and second frequencies, and a plurality of light elements adapted to be supported on the Christmas tree. Each of the light elements comprises a light source for generating visible light, a battery for supplying power to activate the light source, a bistable switch having an input, and an output connected to the light source, and first and second photocells responsive to light signals of the first and second frequencies, respectively, for generating first and second control signals to the input of the bistable switch. The first control signal controls the bistable switch to activate the light element and the second control signal controls the bistable switch to deactivate the light element. Preferably, the light elements activate each other in a cascade fashion.

Abstract: A variable color lighting arrangement includes at least first to third light sources and at least another light source, and allows a desired mixed color light to be obtained in a relatively simpler manner, such that an emission color of a temporary light source is first imaginarily set with an emission color of one of the first to third light sources mixed with another emission color of the said another light source, a mixing ratio is calculated with emission colors of remaining two or more of the plurality of light sources including at least the first to third light sources and the emission color of the temporary source, and a required mixing ratio of the respective light sources for obtaining the desired mixed color light is obtained on the basis of the calculated mixing ratio.

Abstract: A wall-mounted electronic potentiometer system is provided for controlling fluorescent lamps by way of ceiling mounted controllers. This enables control of the control information by way of a 2-wire communication bus to selected ceiling mounted controller using a serial data format.

Abstract: A circuit for a plurality of electrical discharge lamps having a multiplicity of lighting functions comprises a common DC power supply/control unit with socket means to receive plug-in function modules common to all of said lamps, a socket means for connecting the power supply/control unit to an AC mains supply, a bus network and ballasts for respective ones of said plurality of lamps. Each of the plug-in function modules contains all the necessary circuitry and components for a desired lighting function and the ballasts are constructed as low cost disposable items comprising lamp driver circuits only.

Abstract: An illumination level control device (10) is disclosed which sequentially reduces the illumination level of a multi-bulb lamp (12). The illumination level control device (10) incorporates two D flip-flops (38,40) configured in a master-slave relationship wherein the two D flip-flops (38,40) change their respective states when the clock (60) sends a positive-edge of the clock signal thereto. A portion (58) of the device (10) sets the two D flip-flops (38,40) when the wall switch (22) is off for more than a predetermined time. In the case of a three bulb (14,16,18) lamp (12), a zero state preventor (56) prevents all of the bulbs (14,16,18) from being turned off when the wall switch (22) is in the ON position. The zero state preventor (56) effectively eliminates the state wherein the outputs of both of the two D flip-flops (38,40) are low.

Abstract: A luminaire of variable color temperature is arranged for emitting blended color light from luminaire section, with color temperature control signals so transmitted from control section to luminaire-lighting section as to substantially equalize respective differences in reciprocal color temperatures of respective two adjacent stages of the color temperature control signals, to thereby render blended state of emission colors to be variable and a dimming of the blended color light to be realized with the color temperature gradually varied in smooth manner.

Abstract: DC bias does not accumulate on an EL lamp connected in series with a switch circuit including, in one embodiment, two, asymmetric, parallel current paths, one current path for each half cycle of the AC. The first current path includes a first diode for preventing DC bias on the lamp, the first diode is in series with a first transistor between a first terminal and a second terminal. The second current path includes a second diode in series with the base-collector junction of a second transistor between the first terminal and the second terminal. The base of the first transistor is connected to the emitter of the second transistor and to a control terminal. The first transistor and the second transistor are opposite conductivity types. The second current path takes advantage of the fact that the current through an electroluminescent lamp is small and uses the control terminal as a source of current for the lamp.

Abstract: A device for regulating the intensity of light emitted by a lamp includes a core of magnetic material, a first electrical circuit having a primary inductor wrapped around at least a portion of the core of magnetic material, and a second electrical circuit having a secondary inductor wrapped around at least a portion of the core of magnetic material. The first electrical circuit is designed for electrical connection to the lamp, and the primary inductor is arranged in the first electrical circuit in a manner such that a variation in the inductance of the primary inductor will cause a corresponding variation in the intensity of light emitted by the lamp. The second electrical circuit includes a control device (e.g.

Abstract: A dimmer control system includes two discrete silicon controlled rectifiers which respectively energize a lamp load during alternate half cycles of the input AC voltage. The separate placement of the SCRs ensures that much lower temperatures are reached than would occur if a single triac were used to energize a lamp during both half cycles. The system also includes a pair of diacs which energize the respective SCRs when a respective capacitor directly connected to each diac discharges through one of them. The system further includes a respective capacitor charging circuit for each capacitor, each of the two charge circuits including a series connections of the gate to cathode junction of the SCR other than the one which the capacitor being charged discharges through, a diode, a common fixed resistor, and a common variable resistor.

Abstract: A fluorescent light source includes multiple fluorescent lamp tubes driven in parallel by a single RF source. The fluorescent lamp tubes can be twin tube fluorescent lamps or straight fluorescent lamps. RF electrical energy is capacitively coupled to low pressure discharges within each fluorescent lamp tube. External capacitive coupling electrodes can be formed at or near the ends of each fluorescent lamp tube. Alternatively, cold cathode electrodes can be located within the fluorescent lamp tubes. Ballasting of the fluorescent lamp tubes is provided by capacitive coupling between the plasma of the low pressure discharge and the electrodes, thus eliminating the need for external ballasting components.

Abstract: The invention pertains to a switchmode DC to AC converter, and particularly to a master-slave half-bridge converter. The slave half-bridge power converter is controlled by a lower power self-oscillating half-bridge master converter. More particularly, the invention pertains to a high frequency ballast for gas discharge devices, especially, for high pressure sodium lamps, completed by a high voltage ignition apparatus. A pair of self-saturated electronically switched transformers controlled by a low power current source provide a power controlled and frequency modulated high frequency ballast for the gas discharge devices.

Abstract: A non-arcing electrical switch is disclosed wherein a solid-state switching element is operated in response to current flow within an external circuit. The switch is particularly suitable for use within an auxiliary lighting circuit of a gaseous discharge lamp. Because the switch operates in response to the current drawn by the gaseous discharge lamp rather than a specific sensed voltage, it may be used with virtually any type of clamp or lamp operating circuit.

Abstract: A programmable lighting control system for decorative, artistic, and Christmas lighting applications, includes a plurality of outlet receptacles for connection thereto of series or parallel connected Christmas tree lighting strings or the like, a plurality of associated output select switches to individually select a lighting condition signal for each respective outlet receptacle, timing and control circuitry to generate a plurality of lighting condition signals that are applied to solid-state switching devices to drive the outlet receptacles, an output timing phase synchronization feature initiated at user discretion to synchronize the timing phase of each of the plurality of lighting condition signals, and a memory function to retain the last programmed lighting display conditions of user-selected, entirely unique lighting patterns when using a plurality of lighting strings.

Abstract: An electronic ballast circuit for two fluorescent lamps connected in parallel. A single switching inverter connected through a common coupling circuit provides high frequency alternating current for operation of both lamps independently of each other insuring operation of one lamp should the other cease operation. A dual toroidal transformer in the inverter insures both lamps receive current of the same frequency.

Abstract: The present invention is directed to an electronic ballast device for the control of gas discharge lamps. The device is comprised of a housing unit with electronic circuitry and related components. The device accepts a.c. power and rectifies it into various low d.c. voltages to power the electronic circuitry, and to one or more high d.c. voltages to supply power for the lamps. Both the low d.c. voltages and the high d.c. voltages can be supplied directly, eliminating the need to rectify a.c. power. The device switches a d.c. voltage such that a high frequency signal is generated. Because of the choice of output transformers matched to the high frequency (about 38 kHz) and the ability to change frequency slightly to achieve proper current, the device can accept various lamp sizes without modification. The ballast can also dim the lamps by increasing the frequency. The device can be remotely controlled.

Abstract: The invention provides a high-pressure discharge lamp incorporating an outer envelope storing a pair of electric terminals a plurality of arc tubes which are respectively stored in this outer envelope and electrically connected in parallel, and a plurality of ignition aids available for assisting operating of these arc tubes, where these ignition aids are provided for each of these arc tubes and contain potentials different from each other. In addition, the invention also provides a lighting system for operating the high-pressure discharge lamp.

Abstract: A half-bridge inverter is powered from a constant-magnitude DC supply voltage and provides at the inverter's output a first AC output voltage that is describable as a modified squarewave voltage. This first AC voltage is applied across a series-combination of a tank inductor and a tank capacitor, the junction between which is clamped to the DC supply voltage. As a result, a second AC voltage gets established across the tank capacitor; which second AC voltage is also describable as a modified squarewave voltage. However, the phasing of the second AC voltage is delayed by roughly 90.degree. degrees with respect to the first AC voltage; which results in the voltage across the tank inductor being of approximately sinusoidal waveform.

Abstract: An adapter can independently and selectively power two fluorescent lamps. The adapter has a case with two sockets adapted to connect to the two fluorescent lamps. The adapter also has ballasts mounted in the case for inductively conveying current. A base mounted on the case has first, second and third contacts. The first and the third contacts have serially connected between them one of the ballasts and one of the sockets. The other one of the sockets is serially connected with another one of said ballasts, between the second and third contacts.

Abstract: A synchronously-controlled light string includes a plurality of light string units, each of which has a plug in one end and a socket in the other end, thereby allowing the light string units to be coupled together. Each light string unit has a control circuit and a plurality of lights. When the control circuit receives an AC power source signal, the signal is rectified, and frequency divided to obtain a train of clock pulses which are sent to a shifting circuit and a pattern selection circuit to control a driving circuit to drive the lights with a predetermined frequency.

Abstract: The present invention is directed to an electronic ballast device for the control of gas discharge lamps. The device is comprised of a housing unit with electronic circuitry and related components. The device accepts a.c. power and rectifies it into various low d.c. voltages to power the electronic circuitry, and to one or more high d.c. voltages to supply power for the lamps. Both the low d.c. voltages and the high d.c. voltages can be supplied directly, eliminating the need to rectify a.c. power. The device switches a d.c. voltage such that a high frequency signal is generated. Because of the choice of output transformers matched to the high frequency (about 38 kHz) and the ability to change frequency slightly to achieve proper current, the device can accept various lamp sizes without modification. The ballast can also dim the lamps by increasing the frequency. The device can be remotely controlled.