Abstract: A shunt for use in a socket of a string of lights resides in an otherwise typical lamp of a string of lights. The present shunt is a conductive spring held in position by a shunt housing between the two conductive terminals so that both of its curved lateral ends contact the terminals when the bulb holder is removed. When the bulb holder is inserted, a pushrod on the flat central portion of the conductive spring presses the spring down into a well in the shunt housing so that the curved lateral ends of the conductive spring are drawn away from the electrical terminals, thereby allowing current to flow through the Dumet wires to the filament.

Abstract: A mechanical shunt for use in a socket of a string of lights resides in an otherwise typical lamp of a string of lights. The present shunt is a coiled spring shunt inserted in part into a hole formed in one of the electrical terminals in the socket so that it is cantilevered toward the opposing electrical terminal. The bulb holder carries a projection or a “tooth” on its bottom corner that is interposed between the first, cantilevered end of the spring terminal and the first electrical terminal when the holder is inserted into the socket. When the bulb and holder are removed, the spring shunt resiliently returns to engagement with the first electrical terminal.

Abstract: A mechanical shunt for use in a socket of a string of lights resides in an otherwise typical lamp of a string of lights. The present shunt is a pair of cantilevered portions from the electrical terminals inside the socket of a lamp in a string of lights. The portions touch and conduct electrical current when no lamp holder is in the socket but are separated by a button on the bottom of the lamp holder when the lamp holder is not in the socket. The cantilevered portions are formed in such a way that they rub together when opening, closing or when the socket undergoes expansion and contraction with changing temperature in order to prevent the buildup of corrosion on the teeth on the end of the cantilevered portion that would preclude their ability to make good electrical contact when needed.

Abstract: A solid state lighting unit constituted of: a control circuitry; a single string of light emitting diodes, the single string constituted of a plurality of sections each comprising a plurality of light emitting diodes; and a plurality of bypass paths each responsive to the control circuitry, each of the plurality of bypass paths arranged to provide bypass to a particular one of the plurality of sections, wherein the control circuitry is operative to identify an open circuit condition of a particular one of the plurality of sections, and activate the bypass path arranged to bypass the open circuit section, thereby providing light through sections not exhibiting an open circuit condition.

Abstract: Semiconductor light emitting circuits include semiconductor light emitting diodes that are serially connected between a pair of input terminals. Four layer semiconductor devices, such as Shockley diodes and/or thyristors are also provided, a respective one of which is connected across a respective one of the semiconductor light emitting diodes. The four layer semiconductor devices can allow a string of light emitting diodes to continue to be lit if one light emitting diode fails.

Abstract: The electrical wire leads of miniature lights or LED's in a series-wired Christmas light string are gold or silver plated to resist corrosion. The wire leads of any shunt components used in the sockets of the light string can also be plated for corrosion resistance.

Abstract: A series connected LED light string using capacitors as shunts. The shunts are implemented by inserting a capacitor—for example a low breakdown voltage chip capacitor—in every light socket, or internally within each LED. The capacitive shunt continues current in the light string in the event an LED fails by opening electrically—the capacitor shorts out, thus, keeping the string of lights illuminated. The shunt capacitor across the LED also helps filter the pulsating DC voltage to the bulbs and reduces annoying flicker.

Abstract: A light string lamp bypass device is comprised of a plug and a conducting member. The plug is shaped and sized to releasably fit within a lamp socket of the light string. The conducting member is attached to the plug. It is shaped, sized and positioned upon the plug such that the conducting member is electrically connected to the socket terminals, is positioned below the top surface of the plug and is positioned between the socket terminals when the plug is inserted into the lamp socket. The impedance of the conducting member substantially matches the impedance of an operating lamp within a lamp socket of the light string. A section of a light string may be darkened by replacing its lamps with the device. A typical use is for the darkening of a section of a light string connecting two decorated bushes.

Abstract: A circuit to cause the dimming and brightening of a series connected light string periodically by providing a unidirectional shunt and a flasher bulb in at least one of the sockets to intermittently cause the string to go to its dimmer state when the flasher bulb goes out and the full brightness to return when the flasher bulb comes back on. This shunt is preferably provided in the first light socket next to the AC plug. In another embodiment of the present invention, bidirectional shunts are provided in some of the sockets in an otherwise unidirectionally shunted series connected light string for the purpose of achieving random twinkle by inserting flasher bulbs in those sockets. The unidirectional shunts used in the present invention can be a diode array or a rectifier in series with a Zener diode in its Zener direction.

Abstract: A light bulb, such as a miniature light bulb used in Christmas lighting, having a microchip shunt disposed inside the bulb and connected across the filament terminals or leads of the light bulb. If the light bulb is a flasher bulb, any series connected light string can be made to have a plurality of twinkling bulbs without the light string going out when one of these bulbs go out as is the case now when a single flasher bulb is inserted in a series connected light string. The microchip shunt can be back-to-back Zener diode, a diode array, a silicon triggered switch, a thyristor or a thermistor.

Abstract: A series-connected string of light bulbs, operating on AC voltage, each having connected thereacross a voltage regulating shunting circuit which regulates the voltage across an empty or otherwise inoperative socket so as to maintain unidirectional current across each of the remaining sockets in the string during one-half of an AC cycle, thereby insuring continuous but dimmed illumination of the light string. The voltage regulating shunting circuit of the present invention is a silicon rectifier diode connected in series with a voltage regulating diode. The voltage regulating diode may be an array of silicon diodes or a Zener diode. The voltage regulating shunting circuit can be mass produced by using conventional manufacturing techniques.

Abstract: A light unit includes a bulb having a light source with lead wires and a separator, a switch member that includes a support member and a pair of spring terminals, and a socket having two or more conductive terminals and adapted to receive the bulb and the switch member. The switch member is adapted to cause the pair of spring terminals to contact one another to form an electrical short circuit across the pair of conductive terminals and the light source when the bulb is completely or partially removed from the socket. The lead wires form an electrical connection across the conductive terminals and the separator breaks contact between the pair of spring terminals when the bulb is seated in the socket.

Abstract: A lighting device (132) includes a circuit having a power supply and a plurality of light emitting diodes (120) connected in series with the power supply. The plurality of light emitting diodes (120) includes at least two groups of series-connected light emitting diodes, the groups of series-connected light emitting diodes being connected in series. A different optically isolated field effect transistor (U3-U5) is connected in parallel with each group of series-connected light emitting diodes, for selectively shunting around the group of series-connected light emitting diodes. A different capacitor (C8-C10) can also be connected in parallel with each group of series-connected light emitting diodes. A controller (U2) is connected to a gate of each of the optically isolated field effect transistors (U3-U5) for selectively turning the optically isolated field effect transistors (U3-U5) on and off.

Abstract: A circuit is used for driving a plurality of LEDs by an external voltage source. The LEDs are coupled in series. The circuit comprises a plurality of switches coupled to the LEDs in parallel, respectively, for individually controlling the brightness of the LEDs. The circuit further includes a plurality of Pulse-Width Modulation (PWM) signals coupled to the switches, respectively, for individually controlling the switches.

Abstract: A string set of series-connected incandescent bulbs in which substantially all of the bulb filaments in the set are individually provided with a shunt circuit which includes a voltage responsive switch which is inoperative during normal operation of the string set when connected to a source of operating potential and which becomes operative only in response to an increase in the voltage thereacross which exceeds its rating, and in which the remaining bulbs of the circuit continue to receive substantially rated current therethrough and substantially rated voltage thereacross and further continue to be illuminated at substantially constant illumination even though other or substantially all of the other bulbs in the string are either inoperative or are missing from their respective sockets. The voltage responsive switches may be in series with a resistor.

Abstract: A string set of series-connected incandescent bulbs in which substantially all of the bulb filaments in the set are individually provided with a shunt circuit which includes a voltage responsive switch which is inoperative during normal operation of the string set when connected to a source of operating potential and which becomes operative only in response to an increase in the voltage thereacross which exceeds its rating, and in which the remaining bulbs of the circuit continue to receive substantially rated current therethrough and substantially rated voltage thereacross and further continue to be illuminated at substantially constant illumination even though other or substantially all of the other bulbs in the string are either inoperative or are missing from their respective sockets.

Abstract: An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

Abstract: A method and apparatus to equalize the voltage across each light bulb in a low-voltage lighting system, commonly found in the yards of private homes and businesses. The present invention consists of a power compensation element that is inserted in-line with each light bulb connected to the bus lines that distribute current from a power source, such as an electrical transformer, to the light bulbs. The function of the power compensation element is to compensate for the voltage drop along the bus lines due primarily to the electrical resistance of the bus lines. Therefore, a compensation rating of the power compensation element may depend upon its location along the bus lines and the electrical resistivity of the bus lines, as well as the internal electrical resistance of the light bulbs. The preferred embodiment is an electrical resistive power compensation element where the rating of the element is its resistance value.

Abstract: A redundancy circuit for a diode circuit composed of a plurality of diodes connected in series, according to the present invention, includes: bypass circuits, each of which is connected in parallel to each group, the diode circuit being divided into a plurality of group, each group having one or more diodes connected in series, and each bypass circuit including a first voltage-controlled switching device connected in parallel to the corresponding group, and a detection circuit which has a constant voltage device and a fusing circuit, both of which are connected in series, the detection circuit being connected in parallel to the corresponding group; and when, because of increased resistance of any diode, a voltage applied to one of the groups exceeds a given voltage defined by the constant voltage device, the voltage-controlled switching device is turned on so as to bypass a current that is to pass through the corresponding group, whereby continuing the operation of the whole apparatus even when one or more di

Abstract: First resistors (R1, R2) for setting a forward current value are connected in series to light-emitting diodes (LED 1, LED 2) respectively to constitute first serial circuits (112, 113), which are connected to an input terminal (111). Second serial circuits (115, 116) are connected in parallel to the first serial circuits (112, 113) respectively. The second serial circuits (115, 116) are constituted by a combination of a Zener diode (ZD1) and a second resistor (R3), and another combination of a Zener diode (ZD2) and a second resistor (R4). When a higher voltage than rated voltages of the light-emitting diodes (LED 1, LED 2) is applied, the Zener diodes (ZD1, ZD2) shunt current into the second serial circuit (115, 116) to allow the light-emitting diodes (LED 1, LED 2) to light up at desirable luminance levels different from each other.

Abstract: A shunt device for a light socket includes a semiconductor chip which is operably interposed between a pair of electric terminals of the socket. The sockets are in series for a conventional set of display lights, such as holiday lights.

Abstract: The invention provides an elongated lighting apparatus that can withstand temperature fluctuations. The elongated lighting apparatus comprises of the following elements: at least two elongated tubular members fabricated from translucent material. These elongated tubular members are fixed in an end-to-end configuration, separated by a region enabling for thermal expansion/contraction of the members. A substrate upon which a plurality of light emitting devices is placed, is slidably positioned inside each tubular member. End caps seal the open ends of the elongated tubular members. At least one of these end caps has a translucent protrusion that projects towards the region of separation. At least one light emitting device is positioned proximate to an end cap protrusion, thereby illuminating this region. A flexible interconnector encloses and visually conceals separating the adjacent members. The light emitting devices are electrically interconnected.

Abstract: A string set of series-connected incandescent bulbs in which substantially all of the bulb filaments in the set are individually provided with a shunt circuit which includes a voltage responsive switch which is inoperative during normal operation of the string set when connected to a source of operating potential and which becomes operative only in response to an increase in the voltage thereacross which exceeds its rating, and in which the remaining bulbs of the circuit continue to receive substantially rated current therethrough and substantially rated voltage thereacross and further continue to be illuminated at substantially constant illumination even though other or substantially all of the other bulbs in the string are either inoperative or are missing from their respective sockets.

Abstract: A light string includes electrical wires to which a number of bulb sockets are connected in series. Each bulb socket defines a receptacle for receiving and retaining a bulb with the bulb in electrical connection with the electrical wires. A shunt member made of alumina is incorporated in the socket. The shunt member is removably disposed in the receptacle of the socket, independent of the bulb, for being electrically connected to the electrical wires in parallel with the bulb whereby when the bulb burns out, the shunt member maintains the current flowing through the wires. The shunt member further includes an insulation sheath surrounding the alumina section.

Abstract: A string set of series-connected incandescent flasher type lamps in which substantially all of the lamp filaments in the set are individually provided with a voltage regulated shunt circuit, which includes a voltage responsive silicon semiconductor device, which operates in one of two conducting states, neither of which is greater than about 200 ohms. When the flasher lamp is in the “on” or illuminated state, the silicon semiconductor voltage regulating shunt device is in a low impedance state. When the flasher is in the “off” state, the impedance of the silicon semiconductor device is in a lower impedance state equal to or slightly greater than the parallel equivalent impedance of silicon semiconductor device in parallel with the normal operating impedance of the flasher lamp.

Abstract: A string set of series-connected incandescent bulbs in which substantially all of the bulb filaments in the set are individually provided with a shunt circuit which includes a voltage responsive switch which is inoperative during normal operation of the string set when connected to a source of operating potential and which becomes operative only in response to an increase in the voltage thereacross which exceeds its rating, and in which the remaining bulbs of the circuit continue to receive substantially rated current therethrough and substantially rated voltage thereacross and further continue to be illuminated at substantially constant illumination even though other or substantially all of the other bulbs in the string are either inoperative or are missing from their respective sockets.

Abstract: An apparatus and method are provided for interfacing railway controllers with light units, such as LED light unit arrays, to shunt and/or disable test signals not traditionally intended to test non-incandescent light unit arrays.

Abstract: A device for preparation of a machining electrode, especially a machining electrode or bar sinking electrode in an EDM machine for feed into an electrode guide system. The device employs a suction and advance device for suction and advance of the machining electrode and at least one pressure equalization device. Additionally, an electrode change device is disclosed having at least two devices for preparing the machining electrode and a method for preparation of a machining electrode.

Abstract: A string set of series-connected incandescent bulbs adapted to being connected to a source of alternating-current operating potential and in which all of the bulb filaments in the set are individually provided with a non-avalanche shunt circuit which substantially maintains the rated voltage of the bulb across each of the bulb sockets whether or not an operative bulb occupies its respective socket and whereby the illumination of each remaining operative bulb continues to be substantially unchanged and substantially the same rated current continues to flow through said string set despite the absence of a plurality of bulbs from their respective sockets.

Abstract: A power distribution system in which the loads are connected in series to a current source. At each load, a current source to voltage source convertor provides alternative current paths. A serial power distribution current path includes a modulated switch (e.g. a pulse width modulated switch) to control the amount of power delivered to the load via a load current path. The load current path includes a diode which couples a capacitor across the switch, providing a semi-regulated voltage input to a d.c. to d.c. convertor connected across the capacitor. The d.c. to d.c. convertor provides a regulated output voltage, which is connected to the load. The control circuit for modulating the opening and closing of the switch is connected in parallel across the capacitor.

Abstract: An electric series circuit with plural loads such as light bulbs connected in series and plural solid state switching devices, with each switching device connected in parallel with one of the loads. Each switching device conducts current when the load that it is connected in parallel with does not conduct current because the load is burned out. The solid state switching means may be any device with a breakthrough voltage which is high enough that it does not conduct when all of the loads conduct current normally. When one of the loads is burned out, that load does not conduct current and the entire line voltage appears across the switching means in parallel with the burned out load. The switching means breaks down. Accordingly, the switching means conducts current and current flows to the remaining loads. Accordingly, the remaining light bulbs in a string of light bulbs continue to light. The burned out load may be immediately detected and replaced. The switching means may be a sidac.

Abstract: A low cost power supply for neon lamps provides enhanced safety protection. The power supply has a transformer with a return path which is separate from the earth ground so that a fault current can be detected. The power supply has a mid-point connected secondary coil design which operates a mid-point connected neon lamp configuration. A protection circuit detects the fault current flowing between the output terminals and the earth ground. When the fault current is detected, the protection circuit disconnects the input power from the primary winding. An input power reset is required to restart the power supply once the protection circuit has operated.

Abstract: A capacitor (16) coupled in series with series coupled gas discharge lamps (11 and 12) will effectively block direct current from flowing through the capacitor (16). A detector circuit including a high impedance resistor (17) and transistor (18) provide an alternate path for a small direct current flow, thereby enabling a direct current voltage across the capacitor (16) to be detected. The presence or absence of this direct current voltage provides a reliable indicia of the existence or absence of a gas discharge fault.

Abstract: A series-resonant ballast for powering at least one gas discharge lamp (16) having heatable filaments (12,15) includes: DC voltage input terminals (B+,B-); an oscillating resonant converter (55,26,51,52,53) for producing high frequency voltage for application to the gas discharge lamp; a control circuit (58) able to receive a control signal from the DC input terminals and from the resonant converter and operable to initiate and stop the oscillations; and direct current blocking circuits (57,50) coupled across the filaments (12,15) and operable to stop flow of the control signal from the DC input terminals, thereby the ballast will not oscillate and will not draw any power from the DC input terminals, whenever the gas discharge lamp is: (i) removed from the output terminals, (ii) is defective, or (iv) is inoperative.

Abstract: A dual mode high intensity aircraft approach lighting system includes a plurality of lights interconnected by means of power wiring. An improved subsystem for detecting lamp failures is disclosed which permits a positive identification of individual failed lamps at a remote location, such as the control tower of an airport, for instance. The subsystem hardware consists of an operational monitor processor, three lamp controllers, one for each of three lighting loops, one remote lamp transceiver module per lamp, and existing ac loop wiring. The operational monitor processor board initiates a reset of the lamp controller and remotely installed transceiver units by sending a SAMPLE ALL signal to each lamp controller. A comprehensive test of all lamps in each of the three lighting loops is performed. The first lamp controller board sequentially polls each lamp for operational status in the first loop.

Abstract: A starting capacitor disconnect scheme for a fluorescent lamp system in which each starting capacitor shunts one or more series connected fluorescent lamps until all of the fluorescent lamps are ignited. Following ignition of all fluorescent lamps, each starting capacitor is effectively removed from the ballast. Preconditioning of the fluorescent lamp filaments can be limited to the period of time that one or more lamp loads are shunted by the starting capacitor.

Abstract: A circuit (100) for driving a plurality of gas discharge lamps (102, 104), and having: input terminals (126, 130) for connection to a source of voltage supply; output terminals (134, 136, 140) for connection to the lamps in series; an oscillator (124, 132) connected between the input terminals and the output terminals for producing a high-frequency drive voltage at the output terminals; a transformer (106) having a primary winding (108) coupled to the input terminals and having a secondary winding (114) coupled to the output terminals, the transformer secondary winding being coupled at its ends (116, 118) and at an intermediate point (120) to respective ones of the output terminals and the intermediate point (120) of the transformer secondary winding being coupled to its respective output terminal (140) by a capacitor.

Abstract: A ground light or beaconing system for a landing strip having at least one loop of lamps connected in series. Said loop is supplied by a solar cell, via a regulating circuit ensuring the preheating of the lamps while also maintaining a current flowing in the loop adapted to its operation.

Abstract: There is provided a luminaire primarily for use with exit signs and other emergency-type lighting comprising a series string of low-voltage, extremely long-life bulbs positioned within an enclosure for protection and electrically connected to a standard base whereby luminaires having lives of 10 to 30 years may replace standard bulbs without the requirement of retrofitting.

Abstract: An improved non-lighting fluorescent lamp substitute to replace one lamp in a two-lamp series connected circuit so that the circuit is completed through the remaining lamp allowing it to light, whereas without the lamp substitute, the circuit is incomplete if one lamp is removed and then the other lamp is unable to light. In one form, the device is wired into a light fixture, while in another form, it looks like a conventional fluorescent lamp and fits into the sockets of the fixture. Either form cuts power consumption substantially in half with a corresponding reduction in light output. The improvement is a triac in the device that limits the magnitude of the effective arc current by phase angle control to the original design current of the lamp and ballast in order to achieve the normally expected life of the lamp and ballast.

Abstract: A power circuit for N series connected loads according to the present invention includes N transformers having primary windings connected in series across a constant current AC source and secondary windings connected in series with the N loads. N-1 conductors are coupled from a junction between the loads to a corresponding junction between the secondary windings. Failure of one of the loads resulting in an open circuit will not interrupt power to the remaining loads.

Abstract: One of the low voltage output windings of a standard ballast circuit is coupled to one filament of a pair of series connected fluorescent lamps by an external current controller. The current controller acts to restrictively reduce the operating voltage applied to the filaments of one of the lamps to which it is connected, below firing value during start up operation and thereafter maintain a lower running voltage for the lamps without adversely affecting restart.

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: The electric lamp for series arrangement comprises at least one current-supply wire of nickel wire, copper wire or copper cladded wire. A shortcircuit switch is provided, which consists of a vitreous mass, in which copper powder is dispersed and which is fused with the current-supply wires, and of an oxide skin, which is present on the said current-supply wire at the sealing-in area in the mass. The vitreous mass is electrically conducting. An electrical connection between the current-supply wires is not obtained, however, until the filament burns through and the oxide skin breaks down due to the overvoltage then occurring.

Abstract: A filament bypass circuit for use with a string of lamps in series capable of continuing current flow when a lamp in the string fails. Each lamp is provided with a shunt circuit consisting of a series circuit of a diode and a silicon bilateral voltage triggered switch. The switch becomes conductive upon the application of a substantial increase in voltage from the A.C. source and remains conductive until there is an interruption of current flow or current flow drops below its required holding value. The diode insures that during continued operation after a failure there will not be an excessive voltage applied to the remaining lamps, and also serves as an indicator of a failed lamp.

Abstract: A flasher bulb and method of making same by mass production techniques are disclosed. The flasher bulb has first and second nickel wires connected by a tungsten wire to form a loop and a bimetallic strip one end of which is connected to one of the nickel wires, the strip being bent towards the other nickel wire. When the strip is heated by passage of current through the tungsten wire, it makes contact with the other nickel wire to take the tungsten wire out of circuit but retain current flow through the nickel wires. Accordingly in a string of flasher bulbs, extinction of one bulb will not necessary cut off current to the others. The conductive wires and bimetallic strip are assembled in position in a mold and held in place by an insulating disk.

Abstract: In order to prolong the life of incandescent electric light bulbs, an arrangement is provided which consists of two bulbs, one of which constitutes a resistance for the second one.The lamp holder which accommodates the two bulbs comprises two sockets into each of which the base of one bulb is inserted, the two sockets being interconnected in series.

Abstract: An energy-saving instant-start series-sequence fluorescent lamp system includes power-reducing capacitor means connected in series circuit arrangement with one or both lamps in a two-lamp system. A protective device is connected in circuit with a first lamp of the system so that in the event the second lamp fails to operate and causes a high current to flow through the first lamp, the protective device reacts to prevent the system from being damaged. A lamp incorporating the power-reducing capacitor and protective device is also disclosed.

Abstract: A ballast apparatus for series-sequenced gaseous discharge devices includes at least one pair of series-sequenced discharge devices having series-connected filaments with a first rectifier means coupling a filament of one discharge device to the transformer and a second rectifier means coupling the series-connected filaments to the transformer whereby current flow is inhibited until both discharge devices are secured in the fixtures and dangerous socket-to-ground voltages are prevented during discharge device installation.

Abstract: An irradiation apparatus having a housing, a reflector and a source of ultraviolet radiation. The irradiation apparatus has a timing mechanism detachably located within the housing, the timing mechanism being an integral portion of the circuit which supplies power from a power source to the ultraviolet radiation source. The timer is adapted to be removed from the housing and attached to the housing by means of a cord having a non-standard plug to allow the lamp to be operated by means of the timer from a remote position.