Patent Grant
10517149
The present invention generally relates to light emitting diodes (“LEDs”) and LED drivers. The present invention specifically relates to alternating current (“AC”) driven LEDs, LED circuits and AC drive circuits and methods.
None.
The present invention generally relates to light emitting diodes (“LEDs”) and LED drivers. The present invention specifically relates to alternating current (“AC”) driven LEDs, LED circuits and AC drive circuits and methods.
LEDs are semiconductor devices that produce light when a current is supplied to them. LEDs are intrinsically DC devices that only pass current in one polarity and historically have been driven by DC voltage sources using resistors, current regulators and voltage regulators to limit the voltage and current delivered to the LED. Some LEDs have resistors built into the LED package providing a higher voltage LED typically driven with 5V DC or 12V DC.
With proper design considerations LEDs may be driven more efficiently with AC than with DC drive schemes. LED based lighting may be used for general lighting, specialty lighting, signs and decoration such as for Christmas tree lighting. For example, U.S. Pat. No. 5,495,147 entitled LED LIGHT STRING SYSTEM to Lanzisera (hereinafter “Lanzisera”) and U.S. Pat. No. 4,984,999 entitled STRING OF LIGHTS SPECIFICATION to Leake (hereinafter “Leake”) describes different forms of LED based light strings. In both Lanzisera and Leake, exemplary light strings are described employing purely parallel wiring of discrete LED lamps using a step-down transformer and rectifier power conversion scheme. This type of LED light string converts input electrical power, usually assumed to be the common U.S. household power of 110 VAC, to a low voltage, rectified to nearly DC input.
Pat. Pending Application No. 0015968A1 entitled PREFERRED EMBODIMENT TO LED LIGHT STRING to Allen (hereinafter “Allen”) discloses AC powered LED-based light strings. Allen describes LED light strings employing series parallel blocks with a voltage matching requirement for direct AC drive placing fundamental restrictions on the number of diodes (LEDs) on each diode series block, depending on the types of diodes used. Allen discloses that for the forward voltage to be “matched,” in each series block, the peak input voltage must be less than or equal to the sum of the maximum forward voltages for each series block in order to prevent over-driving.
LEDs can be operated from an AC source more efficiently if they are connected in an “opposing parallel” configuration as shown by WO98/02020 and JP11/330561. More efficient LED lighting systems can be designed using high frequency AC drivers as shown by Patent Publication Number 20030122502 entitled Light Emitting Diode Driver (“Clauberg et. al.”) Clauberg et. al. discloses that higher frequency inverters may be used to drive an opposing parallel LED pair, an opposing parallel LED string and/or an opposing parallel LED matrix by coupling the LEDs to a high frequency inverter through a resonant impedance circuit that includes a first capacitor coupled in series to one or more inductors with the impedance circuit coupled in series to opposing parallel LEDs with each set of LEDs having a second series capacitor in series to the impedance circuit. In this system additional opposing parallel configurations of LEDs with capacitors may not be added to or removed from the output of the driver without effecting the lumens output of the previously connected LED circuits unless the driver or components at the driver and/or the opposing parallel LED capacitors were replaced with proper values. By adding or removing the opposing parallel LED circuits the voltage would increase or drop at the inductor and the current would increase or drop through the first series capacitor as the load changed therefore the inductor and all capacitors or entire driver would need to be replaced or adjusted each time additional LEDs were added to or removed from the system.
Patent application number US2004/0080941 entitled Light Emitting Diodes For High AC Voltage Operation And General Lighting discloses that a plurality of opposing parallel series strings of LEDs can be integrated into a single chip and driven with high voltage low frequency mains AC power sources as long as there are enough LEDs in each opposing parallel series string of LEDs to drop the total source voltage across the series LEDs within the chip. Patent numbers WO2004023568 and JP2004006582 disclose that a plurality of opposing parallel series strings or opposing parallel series matrix of LEDs can be integrated into a single chip and mounted on an insulating substrate and driven with a high drive voltage and low drive current as long as there are enough LEDs in each opposing parallel series string of LEDs to drop the total source voltage across the series LEDs within the chip. These patents and application disclose that for single chip or packaged LED circuits a plurality of opposing parallel series strings are required with the total number of LEDs in each series string needing to be equal to or greater than the AC voltage source in order to drop the total forward voltage and provide the required drive current when driven direct with low frequency AC mains power sources.
The present invention addresses the above-noted shortcomings of the prior art while providing additional benefits and advantages.
According to one broad aspect of the invention a lighting system is provided having one or more LED circuits. Each LED circuit has at least two diodes connected to each other in opposing parallel relation, wherein at least one of which such diodes is an LED. As used throughout the application, the term diode may mean any type of diode capable of allowing current to pass in a single direction, including but not limited to, a standard diode, a schottky diode, a zener diode, and a current limiting diode. A driver is connected to the one or more LED circuits, the driver providing an AC voltage and current to the one or more LED circuits. The driver and the LED circuits form a driven circuit. The driver and the LED circuits are also configured such that LED circuits may be added to or subtracted (intentionally or by component failure) from the driven circuit:
(a) without significantly affecting the pre-determined desired output range of light from any individual LED; and,
(b) without the need to: (i) change the value of any discrete component; or, (ii) to add or subtract any discrete components, of any of the pre-existing driven circuit components which remain after the change.
In another embodiment of the invention at least one capacitor is connected to and part of each LED circuit. In yet another embodiment, at least one resistor is connected to and is part of each opposing parallel LED circuit noted above. The resistor is connected in series with the at least one capacitor.
According to another aspect of the invention an LED circuit (sometimes referred to as an “AC LED”) can comprise two opposing parallel LEDs, an opposing parallel LED string or an opposing parallel LED matrix. These opposing parallel LEDs may have a capacitor in series connected to at least one junction of the connected opposing parallel configurations within a single chip, a single package, an assembly or a module.
When a real capacitor is connected in series in one or more lines between an LED and an AC power source, there is a displacement current through that capacity of magnitude: I=2ΠfCV. The capacitor in the LED circuits of the invention regulates the amount of current and forward voltage delivered to the one or more opposing parallel LEDs based on the voltage and frequency provided by the AC driver. Based on the number of LEDs in the LED circuit the opposing parallel connections provide two or more junctions to which at least one series capacitor may be connected in series of at least one power connection lead. In some embodiments, LED circuits may also use a series resistor in addition to the capacitor providing an “RC” resistor capacitor network for certain LED circuit driver coupling that does not provide protection against surge currents to the LED circuits.
According to another aspect of the invention an LED circuit may comprise a single LED or a series string of diodes and/or LEDs connected to a full bridge rectifier capable of rectifying a provided AC voltage and current for use by the series string of diodes and/or LEDs. The rectifier may be formed as part of the LED circuit, or may be formed separately, having leads provided on both the output of the driver and the input of the LED circuit to allow the LED circuit to connect directly to the driver. In order to protect the LED circuit from voltage spikes a capacitor may be connected across the inputs of the bridge rectifier. The capacitor may also be used for smoothing the AC waveform to reduce ripple. A capacitor may likewise be connected between one rectifier input and the AC voltage and current source in order to limit the DC current flow to protect the LEDs. The bridge diode and LED circuit may be packaged separate or together, and may be configured within a single chip or two chips, a single package or two packages, an assembly, or a module.
According to another aspect of the invention, a single bridge rectifier may be used to drive parallel LEDs or series strings of diodes and/or LEDs. Alternatively, it is contemplated by the invention that each LED circuit requiring a bridge rectifier to utilize both the high and low phases of an AC power wave may include its own full bridge rectifier integrated or otherwise connected thereto. In embodiments where each LED circuit includes its own rectifier, additional LED circuits may be added in parallel across an AC voltage and current source to any existing LED circuits without concern of connecting to any existing bridge rectifiers or, where used, capacitors. Providing each LED circuit with its own bridge rectifier has the further advantage of scaling capacitors included in the circuit for voltage protection and/or current limiting to be matched to a particular LED or string of diodes and/or LEDs.
It should be noted that “package” or “packaged” is defined herein as an integrated unit meant to be used as a discrete component in either of the manufacture, assembly, installation, or modification of an LED lighting device or system. Such a package includes LED's of desired characteristics with capacitors and or resistors (when used) sized relative to the specifications of the chosen LED's to which they will be connected in series and with respect to a predetermined AC voltage and frequency.
Preferred embodiments of a package may include an insulating substrate whereon the LEDs, capacitors and/or resistors are formed or mounted. In such preferred embodiments of a package, the substrate will include electrodes or leads for uniform connection of the package to a device or system associated with an AC driver or power source or any individually packaged rectifiers used to rectify AC voltage and current. The electrodes, leads, and uniform connection may include any currently known means including mechanical fit, and/or soldering. The substrate may be such as sapphire, silicon carbide, galium nitride, ceramics, printed circuit board material, or other materials for hosting circuit components.
A package in certain applications may preferably also include a heat sink, a reflective material, a lens for directing light, phosphor, nano-chrystals or other light changing or enhancing substances. In sum, according to one aspect of the invention, the LED circuits and AC drivers of the present invention permit pre-packaging of the LED portion of a lighting system to be used with standardized drivers (and when necessary full wave rectifiers) of known specified voltage and frequency output. Such packages can be of varied make up and can be combined with each other to create desired systems given the scalable and compatible arrangements possible with, and resulting from, the invention.
According to one aspect of the invention, AC driven LED circuits (or “driven circuits”) permit or enable lighting systems where LED circuits may be added to or subtracted (either by choice or by way of a failure of a diode) from the driven circuit without significantly affecting the pre-determined desired output range of light from any individual LED and, without the need to: (i) change the value of any discrete component; or, (ii) to add or subtract any discrete components, of any of the pre-existing driven circuit components which remain after the change. During design of a lighting system, one attribute of the LEDs chosen will be the amount of light provided during operation. In this context, it should be understood that depending on the operating parameters of the driver chosen, the stability or range of the voltage and frequency of the driver will vary from the nominal specification based upon various factors including but not limited to, the addition or subtraction of the LED circuits to which it becomes connected or disconnected. Accordingly, as sometimes referred to herein, drivers according to the invention are described as providing “relatively constant” or “fixed” voltage and frequency. The extent of this relative range may be considered in light of the acceptable range of light output desired from the resulting circuit at the before, during, or after a change has been made to the lighting system as a whole. Thus it will be expected that a pre-determined range of desired light output will be determined within which the driven LED circuits of the invention will perform whether or not additional or different LED circuits have been added or taken out of the driven circuit as a whole or whether additional or different LED circuits have been added proximate any existing LED circuits or positioned remotely.
According to another aspect of the invention an LED circuit may be at least one pre-packaged LED and one pre-packaged diode connected together opposing parallel of each other, two opposing parallel pre-packaged LEDs, an opposing parallel LED string of pre-packaged LEDs, an opposing parallel LED matrix of pre-packaged LEDs optionally having a capacitor in series of at least one junction of the connected LED circuits. It is contemplated that the LED circuit may also be at least one of a single LED or series string of diodes and/or LEDs having a bridge rectifier connected across the the single LED or string of diodes. In embodiments where a series string of diodes and/or LEDs and a rectifier is utilized, each LED may likewise be pre-packaged. The rectifier may optionally having a capacitor connected across the rectifier inputs and/or a capacitor connected between to an input of the rectifier for connection between the rectifier and a AC voltage and current source. In either embodiment, utilizing an LED circuit capacitor may allow for direct coupling of at least one LED circuit to the LED driver without additional series components such as capacitors and/or inductors between the LED circuit driver and the LED circuits. The LED circuit driver provides a relatively fixed voltage and relatively fixed frequency AC output even with changes to the load using feedback AC voltage regulator circuitry. The LED circuit's may be directly coupled and scaled in quantity to the LED circuit driver without affecting the other LED circuit's lumen output as long as the LED circuit driver maintains a relatively fixed voltage and relatively fixed frequency AC output.
According to an aspect of the invention, an LED circuit driver provides a relatively fixed voltage and relatively fixed frequency AC output such as mains power sources. The LED circuit driver output voltage and frequency delivered to the LED circuit may be higher than, lower than, or equal to mains power voltage and frequencies by using an LED circuit inverter driver. The LED circuit inverter driver providing higher frequencies is preferable for LED circuits that are integrated into small form LED packages that include integrated capacitors or resistor capacitor “RC” networks. The LED circuit inverter driver has feedback circuitry such as a resistor divider network or other means allowing it to sense changes to the load and re-adjust the frequency and/or voltage output of the LED circuit driver to a desired relatively fixed value. The LED circuit driver may also provide a soft-start feature that reduces or eliminates any surge current from being delivered to the LED circuit when the LED circuit driver is turned on. Higher frequency and lower voltage LED circuit inverter drivers are preferred enabling smaller package designs of LED circuits as the capacitor at higher frequencies would be reduced in size making it easier to integrate into a single LED circuit chip, package, assembly or module.
According to the invention LED circuits may have a resistor capacitor (“RC”) network connected together in series or separate from the the LED circuits. The maximum resistor value needed is only that value of resistance needed to protect the one or more LEDs within the LED circuit from surge currents that may be delivered by LED circuit drivers that do not provide soft start or other anti surge current features. Direct mains power coupling would require RC network type LED circuits as the mains power source delivers surge currents when directly coupled to an LED circuit.
The higher frequency LED circuit inverter driver may be a halogen or high intensity discharge (HID) lamp type driver with design modifications for providing a relatively fixed voltage and relatively fixed frequency output as the LED circuit load changes. Meaning if the LED circuit inverter driver is designed to have an output voltage of 12V at a frequency of 50 Khz the LED circuit driver would provide this output as a relatively constant output to a load having one or more than one LED circuits up to the wattage limit of the LED circuit driver even if LED circuits were added to or removed from the output of the LED circuit driver.
The higher frequency inverter having a relatively fixed voltage and relatively fixed frequency output allows for smaller components to be used and provides a known output providing a standard reference High Frequency LED circuit driver enabling LED circuits to be manufactured in volume in existing or reasonably similar LED package sizes with integrated capacitors or RC networks based on the number of LEDs desired in the LED circuit package.
Patent publication number 20030122502 entitled Light Emitting Diode driver (Clauberg and Erhardt) does not disclose the use of a high frequency inverter driver having a means or keeping a relatively fixed voltage and relatively frequency in response to changes in the load. According to the present invention described herein, by not having additional components such as an inductor or capacitor in series between the LED circuit and the LED circuit driver one LED circuit at a time may be added to or removed from the LED circuit driver output without having to change any components, the LED circuit driver or make adjustments to the LED circuit driver. Additionally, according to this invention the lumen output of the existing LED circuits stays relatively constant due to the self-regulating nature of each individual LED circuit when driven with the relatively fixed frequency and voltage of the LED circuit driver. This level of scalability, single chip LED circuit packaging and standardization is not possible with the prior art using an inductor in series between the LEDs or other components due to the voltage or current increase or drop across the inductors and capacitors in response to changes in the load.
Prior art for single chip LED circuits, for example those disclosed in WO2004023568 and JP2004006582 do not provide a way to reduce the number of LEDs within the chip below the total forward voltage drop requirements of the source. The present invention however, enables an LED circuit to be made with any number of LEDs within a single chip, package or module by using, where desired, transformers, capacitors, or RC networks to reduce the number of LEDs needed to as few as one single LED. Improved reliability, integration, product and system scalability and solid state lighting design simplicity may be realized with LED circuits and the LED circuit drivers. Individual LED circuits being the same or different colors, each requiring different forward voltages and currents may be driven from a single source LED circuit driver. Each individual LED circuit can self-regulate current by matching the capacitor or RC network value of the LED circuit to the known relatively fixed voltage and frequency of the LED circuit driver whether the LED circuit driver is a mains power source, a high frequency LED circuit driver or other LED circuit driver capable of providing a relatively fixed voltage and relatively fixed frequency output.
When a real capacitor is connected in series in one or more lines between an LED and an AC power source, there is a displacement current through that capacity of magnitude: I=2ΠfCV. This means that one can predetermine the amount of current to be delivered through a capacitance based upon a known voltage and frequency of an AC source, allowing for each LED circuit containing a series capacitor to have the specific or ideal current required to provide the desired amount of light from the LED circuit.
According to other aspects of the invention, the LED circuit driver may be coupled to a dimmer switch that regulates voltage or frequency or may have integrated circuitry that allows for adjustability of the otherwise relatively fixed voltage and/or relatively fixed frequency output of the LED circuit driver. The LED circuits get brighter as the voltage and/or frequency of the LED circuit driver output is increased to the LED circuits.
One form of the invention is at least one LED and one diode connected together opposing parallel of each other, two opposing parallel LEDs, an opposing parallel LED string and/or opposing parallel LED matrix having a capacitor in series of at least one connected junction of the connected opposing parallel LED configurations within a single chip, a single package, an assembly or a module. When desired, the LED circuit with capacitor may be placed on an insulating substrates such as but not necessarily ceramic or sapphire and/or within various LED package sizes; materials and designs based of product specifications or assembled on printed circuit board material. Any integrated LED circuit capacitors should be scaled to a predetermined value enabling the LED circuit to self-regulate a reasonably constant and specific current when coupled to an LED circuit driver that provides a relatively fixed voltage and frequency output. Utilized LED circuit capacitors may be of a value needed to provide the typical operating voltage and current of the LED circuit when designed for coupling to a specific LED circuit driver.
Another form of the invention is an LED circuit comprising at least one LED and one diode connected together opposing parallel of each other, two opposing parallel LEDs, an opposing parallel LED string and/or opposing parallel LED matrix having a series resistor capacitor (“RC”) network connected together in series or independently in series between at least one connected junction of the opposing parallel LEDs and the respective power connection of the LED circuit. When desired, the opposing parallel LEDs and RC network may be placed on an insulating substrate such as but not necessarily ceramic or sapphire and/or within various LED package sizes; materials and designs based of product specifications or assembled on printed circuit board material. The LED circuit RC network may be of a value needed to provide the typical operating voltage and current of the LED circuit when designed for coupling to a specific LED circuit driver.
Another form of the invention is an LED circuit comprising a matrix of two opposing parallel LEDs connected together in parallel with every two opposing parallel LEDs having an individual capacitor in series to the power source connection if desired. The entire parallel array of opposing parallel LED circuits, including capacitors when used, may be may be placed on an insulating substrate such as but not necessarily ceramic or sapphire and/or within various LED package sizes; materials and designs based of product specifications or assembled on printed circuit board material. The opposing parallel matrix of LED circuits integrated in the LED circuit package may be RC network type LED circuits.
Another form of the invention is an LED circuit comprising a matrix of opposing parallel LEDs connected together in parallel with every set of opposing parallel LEDs having an individual RC network in series to the power connection lead if desired.
Another form of the invention is an LED circuit comprising a matrix of opposing parallel LEDs connected together in parallel, a capacitor connected in series to at least one side of the line going to the matrix of opposing parallel LEDs with every set of opposing parallel LEDs having an individual resistor in series to the power connection if desired.
Yet another form of the invention is an LED circuit comprising opposing parallel series strings of LEDs connected together and driven direct with a high frequency AC voltage equal to or less than to total series voltage drop of the opposing parallel series strings of LEDs within the LED circuit.
Yet another form of the invention is a LED circuit comprising a single LED or a series string of diodes and/or LEDs and a bridge rectifier connected across the LED or string of diodes and/or LEDs. The rectifier may optionally include a capacitor connected across the inputs of the rectifier. The rectifier may additionally, or alternatively, optionally include a capacitor connected in series with one input, the capacitor being capable of connecting the rectifier input to an AC voltage and current source.
Yet another form of the invention is a LED circuit comprising a single LEDs or a series strings of diodes and/or LEDs connected in parallel across the output of a bridge rectifier. The rectifier may optionally include a capacitor connected across the inputs of the rectifier. The rectifier may additionally, or alternatively, optionally include a capacitor connected in series with one input, the capacitor being capable of connecting the rectifier input to an AC voltage and current source.
Another form of the invention comprises a method of driving LED circuits direct from an AC power source (“LED circuit driver”) having a relatively fixed voltage and relatively fixed frequency. The LED circuit driver may be a mains power source, the output of a transformer, a generator or an inverter driver that provides a relatively fixed voltage and relatively fixed frequency as the load changes and may be a higher or lower frequency than the frequencies of mains power sources. The LED circuit driver provides a relatively fixed voltage and relatively fixed frequency output even when one or more LED circuits are added to or removed from the output of the LED circuit driver. Higher frequency inverters with lower output voltages are used as one LED circuit driver in order to reduce component size and simplify manufacturing and standardization of LED circuits through the availability of higher frequency LED circuit drivers. The LED circuit driver may also include circuitry that reduces or eliminates surge current offering a soft-start feature by using MOSFET transistors, IGBT transistors or other electronic means. The LED circuit driver may also be pulsed outputs at a higher or lower frequency than the primary frequency.
Another form of the invention is an LED lighting system comprising an LED circuit array having a plurality of different LED circuits each drawing the same or different currents, each having the same or different forward operating voltages, and each delivering the same or different lumen outputs that may be the same or different colors and an LED circuit driver coupled to the LED circuit array. The LED circuit driver delivering a relatively fixed t frequency and voltage output allows for mixing and matching of LED circuits requiring different forward voltages and drive currents. The LED circuits may be connected to the output of an LED circuit driver in parallel one LED circuit at a time within the limit of the wattage rating of the LED circuit driver with no need to change or adjust the LED circuit driver as would typically be required with DC drivers and LEDs when increasing or reducing the load with LEDs and other components. Never having to go back to the power source allows for more efficient integration and scalability of lighting systems designed with LED circuits and allows for a single driver to independently provide power to multiple independently controlled LED circuits in the system. Introducing an inductor and/or an additional capacitor such as the impedance circuit described in prior art between the LED circuit drive source and the LED circuits would require changes to the driver or components and prohibit scalability, standardization and mass production of AC-LEDs with integrated capacitors or RC networks.
With the LED circuit driver providing a known relatively constant AC voltage and frequency, mass production of various LED circuits with specific capacitor or RC network values would deliver 20 mA, 150 mA or 350 mA or any other desired current to the LED circuit based on the output of the specified LED circuit driver. The relatively fixed voltage and frequency allows for standardization of LED circuits through the standardization of LED circuit drivers.
In another aspect, a transistor is coupled to at least one power connection of the LED circuit or built into the LED circuit package in series between the power connection lead and the LED circuit with the transistor being operable to control (e.g., varying or diverting) the flow of the alternating current through the LED circuit through a capacitance within the transistor.
The foregoing forms as well as other forms, features and advantages of the present invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the present invention rather than limiting, the scope of the present invention being defined by the appended claims and equivalents thereof.
and
While this invention is susceptible to embodiments in many different forms, there is described in detail herein, preferred embodiments of the invention with the understanding that the present disclosures are to be considered as exemplifications of the principles of the invention and are not intended to limit the broad aspects of the invention to the embodiments illustrated.
The present invention is directed to an LED light emitting device and LED light system capable of operating during both the positive and negative phase of an AC power supply. In order to operate during both phases provided by an AC power, as is shown herein, the circuit must allow current to flow during both the positive and negative phases and LED light emitting devices may be configured such that at least one LED is capable of emitting light during one or both of the positive or negative phases. In order to accomplish this, the LED circuit itself may be configured so as to allow current to pass during both phases, or the device may include a bridge rectifier to rectify AC power for use by single LEDs, series strings of LEDs, and parallel series strings of LEDs. Rectification may be accomplished within the light emitting device, or prior to any power being provided to the same. Once integrated into a light system, the present invention further contemplates a driver having the ability to provide a substantially constant voltage at a substantially constant frequency, and that the driver be configured in a manner which will allow LED light emitting devices to be added to or subtracted from the system, regardless of configuration, without having to add, subtract, or change the values of discrete circuit components and without affecting the light output of any individual LED.
Rather than be packaged together and mounted on a single substrate, and no matter whether the LEDs and diodes are integrated into a single package or are discrete individual LEDs and/or diodes wire-bonded together, as disclosed in
Regardless of whether rectifier 302 and LEDs 306 are integrated or mounted in a single package or are discretely packaged and connected, in order to drop higher voltages any number of LEDs may be connected in series or parallel in a device to match a desired voltage and light output. For example, in a lighting device that is run off of a 120 V source and contains LEDs having a forward operating voltage of 3V each connected to a bridge rectifier having diodes also having a forward operating voltage of 3V each, approximately 38 LEDs may be placed in series to drop the required voltage.
Any of the aforementioned AC drive methods may likewise be used with the devices embodied in
For example,
Similarly, AC drive Method 186 may be utilized may be used with a single or plurality of devices 214 as disclosed in
In the broad sense, the directional circuit 2014 is a loop circuit which includes one or more circuit elements causing the loop circuit to be asymmetric to current flow. Again it is important that the directional circuit 2014 has no continuous conductive path to earth ground, or a battery ground. As such, and as disclosed in
The circuit 2010 is preferably used for delivering power and sensing proximity. The circuit 2010 is also preferably useful in TTL logic applications as disclosed in
In particular,
Also as disclosed in
According to another embodiment,
According to another aspect of the invention, the ground switch 2090 is provided to provide a non-continuous connection to a circuit, such as the ground circuit disclosed in
The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of ordinary skill in the art without departing from the scope of the invention, which is defined by the claims appended hereto.
The present application is a continuation of U.S. patent application Ser. No. 15/797,806 filed Oct. 30, 2017, which is U.S. patent application Ser. No. 15/334,020 filed Oct. 25, 2016, which is a continuation-in-part of U.S. patent application Ser. No. 14/948,635 (now U.S. Pat. No. 9,615,420) filed Nov. 23, 2015, which is a divisional application of U.S. patent application Ser. No. 13/697,646 (now U.S. Pat. No. 9,198,237) filed Nov. 13, 2012 which is a 371 National Phase Application of International Application No. PCT/US2011/0363359 filed May 12, 2011 which claims priority to U.S. Provisional Application No. 61/333,963 filed May 12, 2010 and is a continuation-in-part of International Application No. PCT/US2010/062235 filed Dec. 28, 2010 which claims priority to U.S. Provisional Application No. 61/284,927 filed Dec. 28, 2009 and U.S. Provisional Application No. 61/335,069 filed Dec. 31, 2009 and is a continuation-in-part of U.S. patent application Ser. No. 12/287,267 (now U.S. Pat. No. 8,179,055), filed Oct. 6, 2008, which claims priority to U.S. Provisional Application No. 60/997,771, filed Oct. 6, 2007; U.S. patent application Ser. No. 12/364,890 (now U.S. Pat. No. 8,148,905) filed Feb. 3, 2009 which is a continuation of U.S. application Ser. No. 11/066,414 (now U.S. Pat. No. 7,489,086) filed Feb. 25, 2005 which claims priority to U.S. Provisional Application No. 60/547,653 filed Feb. 25, 2004 and U.S. Provisional Application No. 60/559,867 filed Apr. 6, 2004; International Application No. PCT/US2010/001597 filed May 28, 2010 which is a continuation-in-part of U.S. application Ser. No. 12/287,267 (now U.S. Pat. No. 8,179,055), and claims priority to U.S. Provisional Application No. 61/217,215, filed May 28, 2009; International Application No. PCT/US2010/001269 filed Apr. 30, 2010 which is a continuation-in-part of U.S. application Ser. No. 12/287,267 (now U.S. Pat. No. 8,179,055), and claims priority to U.S. Provisional Application No. 61/215,144, filed May 1, 2009;—the contents of each of these applications are expressly incorporated herein by reference. U.S. patent application Ser. No. 15/797,806 is also a continuation-in-part of U.S. patent application Ser. No. 13/519,487 filed Jun. 27, 2012 which is a 35 U.S.C. 371 national phase filing of International Application No. PCT/US2010/062235, filed Dec. 28, 2010, which claims priority to U.S. Provisional Application No. 61/284,927, filed Dec. 28, 2009 and U.S. Provisional Application No. 61/335,069 filed Dec. 31, 2009; International Application No. PCT/US2010/062235 is also a continuation-in-part of U.S. patent application Ser. No. 12/287,267 (now U.S. Pat. No. 8,179,055), filed Oct. 6, 2008, which claims priority to U.S. Provisional Application No. 60/997,771, filed Oct. 6, 2007; International Application No. PCT/US2010/062235 is also a continuation-in-part of U.S. patent application Ser. No. 12/364,890 (now U.S. Pat. No. 8,148,905) filed Feb. 3, 2009 which is a continuation of U.S. application Ser. No. 11/066,414 (now U.S. Pat. No. 7,489,086) filed Feb. 25, 2005 which claims priority to U.S. Provisional Application No. 60/547,653 filed Feb. 25, 2004 and U.S. Provisional Application No. 60/559,867 filed Apr. 6, 2004; International Application No. PCT/US2010/062235 is also a continuation in part of International Application No. PCT/US2010/001597 filed May 28, 2010 which is a continuation-in-part of U.S. application Ser. No. 12/287,267, and claims priority to U.S. Provisional Application No. 61/217,215, filed May 28, 2009; International Application No. PCT/US2010/062235 is also a continuation-in-part of International Application No. PCT/US2010/001269 filed Apr. 30, 2010 which is a continuation-in-part of U.S. application Ser. No. 12/287,267, and claims priority to U.S. Provisional Application No. 61/215,144, filed May 1, 2009—the contents of each of these applications are expressly incorporated herein by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3869641 | Goldberg | May 1975 | A |
| 4218627 | Kiesel | Aug 1980 | A |
| 4271408 | Teshima et al. | Jun 1981 | A |
| 4298869 | Okuno | Nov 1981 | A |
| 4380721 | Bullock et al. | Apr 1983 | A |
| 4506318 | Nilssen | Mar 1985 | A |
| 4535203 | Jenkins et al. | Aug 1985 | A |
| 4751398 | Ertz, III | Jun 1988 | A |
| 5180952 | Nilssen | Jun 1993 | A |
| 5309062 | Perkins et al. | May 1994 | A |
| 5442258 | Shibata | Aug 1995 | A |
| 5559681 | Duarte | Sep 1996 | A |
| 5575459 | Anderson | Nov 1996 | A |
| 5640061 | Bornhorst et al. | Jun 1997 | A |
| 5675485 | Seong | Oct 1997 | A |
| 5683436 | Mendes et al. | Nov 1997 | A |
| 5699218 | Kadah | Dec 1997 | A |
| 5739639 | Johnson | Apr 1998 | A |
| 5790013 | Hauck | Aug 1998 | A |
| 5821699 | Moisin | Oct 1998 | A |
| 6040663 | Bucks et al. | Mar 2000 | A |
| 6107744 | Bavaro et al. | Aug 2000 | A |
| 6113248 | Mistopoulos et al. | Sep 2000 | A |
| 6157551 | Barak et al. | Dec 2000 | A |
| 6183104 | Ferrara | Feb 2001 | B1 |
| 6380693 | Kastl | Apr 2002 | B1 |
| 6412971 | Wojnarowski et al. | Jul 2002 | B1 |
| 6430064 | Tsuchimoto et al. | Aug 2002 | B1 |
| 6541919 | Roach et al. | Apr 2003 | B1 |
| 6577072 | Saito et al. | Jun 2003 | B2 |
| 6580228 | Chen et al. | Jun 2003 | B1 |
| 6614103 | Durocher et al. | Sep 2003 | B1 |
| 6697130 | Weindorf et al. | Feb 2004 | B2 |
| 6762562 | Leong | Jul 2004 | B2 |
| 6781570 | Arrigo et al. | Aug 2004 | B1 |
| 6884973 | Castracane | Apr 2005 | B2 |
| 6936968 | Cross et al. | Aug 2005 | B2 |
| 6949772 | Shimizu et al. | Sep 2005 | B2 |
| 6961190 | Tamaoki et al. | Nov 2005 | B1 |
| 7019062 | Van Beek et al. | Mar 2006 | B2 |
| 7019662 | Shackle | Mar 2006 | B2 |
| 7038400 | Rimmer et al. | May 2006 | B2 |
| 7053560 | Ng | May 2006 | B1 |
| 7061188 | Katyl et al. | Jun 2006 | B1 |
| 7067992 | Leong et al. | Jun 2006 | B2 |
| 7144131 | Rains | Dec 2006 | B2 |
| 7288902 | Melanson | Oct 2007 | B1 |
| 7350936 | Ducharme et al. | Apr 2008 | B2 |
| 7365718 | Tsuchida et al. | Apr 2008 | B2 |
| 7489086 | Miskin et al. | Feb 2009 | B2 |
| 7521872 | Bruning | Apr 2009 | B2 |
| 7646029 | Mueller et al. | Jan 2010 | B2 |
| 7808189 | Hollnberger et al. | Oct 2010 | B2 |
| 7859196 | Lee et al. | Dec 2010 | B2 |
| 7936132 | Quek et al. | May 2011 | B2 |
| 8033686 | Recker et al. | Oct 2011 | B2 |
| 8148905 | Miskin et al. | Apr 2012 | B2 |
| 8179055 | Miskin et al. | May 2012 | B2 |
| 8237581 | Ries, II | Aug 2012 | B2 |
| 8531118 | Miskin et al. | Sep 2013 | B2 |
| 8613997 | Day | Dec 2013 | B2 |
| 8648539 | Miskin et al. | Feb 2014 | B2 |
| 8841855 | Miskin | Sep 2014 | B2 |
| 9198237 | Miskin | Nov 2015 | B2 |
| 9247597 | Miskin et al. | Jan 2016 | B2 |
| 9249953 | Miskin | Feb 2016 | B2 |
| 9516716 | Miskin et al. | Dec 2016 | B2 |
| 9615420 | Miskin | Apr 2017 | B2 |
| 9693405 | Miskin | Jun 2017 | B2 |
| 9750098 | Miskin et al. | Aug 2017 | B2 |
| 9807827 | Miskin et al. | Oct 2017 | B2 |
| 20020030455 | Ghanem | Mar 2002 | A1 |
| 20020047646 | Lys et al. | Apr 2002 | A1 |
| 20020060526 | Timmermans et al. | May 2002 | A1 |
| 20020113246 | Nagai et al. | Aug 2002 | A1 |
| 20020114155 | Katogi et al. | Aug 2002 | A1 |
| 20030001657 | Worley, Sr. et al. | Jan 2003 | A1 |
| 20030043611 | Bockle et al. | Mar 2003 | A1 |
| 20030057886 | Lys et al. | Mar 2003 | A1 |
| 20030122502 | Clauberg et al. | Jul 2003 | A1 |
| 20030169014 | Kadah | Sep 2003 | A1 |
| 20030175004 | Garito et al. | Sep 2003 | A1 |
| 20030179585 | Lefebvre | Sep 2003 | A1 |
| 20040070520 | Sharp et al. | Apr 2004 | A1 |
| 20040079953 | Mednik et al. | Apr 2004 | A1 |
| 20040080941 | Jiang et al. | Apr 2004 | A1 |
| 20040105264 | Spero | Jun 2004 | A1 |
| 20040140771 | Kim et al. | Jul 2004 | A1 |
| 20040183380 | Otake | Sep 2004 | A1 |
| 20040189218 | Leong et al. | Sep 2004 | A1 |
| 20040196636 | Kim | Oct 2004 | A1 |
| 20040201988 | Allen | Oct 2004 | A1 |
| 20040206970 | Martin | Oct 2004 | A1 |
| 20050040773 | Lebens et al. | Feb 2005 | A1 |
| 20050093461 | Cull et al. | May 2005 | A1 |
| 20050110426 | Shao | May 2005 | A1 |
| 20050122062 | Hsu | Jun 2005 | A1 |
| 20050151511 | Chary | Jul 2005 | A1 |
| 20050162096 | Bertrand | Jul 2005 | A1 |
| 20050168156 | Li et al. | Aug 2005 | A1 |
| 20050173990 | Andersen et al. | Aug 2005 | A1 |
| 20050218838 | Lys | Oct 2005 | A1 |
| 20050230600 | Olson et al. | Oct 2005 | A1 |
| 20060038542 | Park et al. | Feb 2006 | A1 |
| 20060087843 | Setomoto et al. | Apr 2006 | A1 |
| 20060103913 | Handschy et al. | May 2006 | A1 |
| 20060138971 | Uang et al. | Jun 2006 | A1 |
| 20060158130 | Farrukawa | Jul 2006 | A1 |
| 20070069663 | Burdalski et al. | Mar 2007 | A1 |
| 20070228999 | Kit | Oct 2007 | A1 |
| 20070273299 | Miskin et al. | Nov 2007 | A1 |
| 20080116816 | Neuman et al. | May 2008 | A1 |
| 20080136347 | Lin et al. | Jun 2008 | A1 |
| 20080158915 | Williams | Jul 2008 | A1 |
| 20080198613 | Cruickshank | Aug 2008 | A1 |
| 20080203405 | Rooymans | Aug 2008 | A1 |
| 20080203936 | Mariyama et al. | Aug 2008 | A1 |
| 20080211421 | Lee et al. | Sep 2008 | A1 |
| 20080218098 | Lee et al. | Sep 2008 | A1 |
| 20090021185 | Ng | Jan 2009 | A1 |
| 20090295300 | King | Dec 2009 | A1 |
| 20100039794 | Ghanem et al. | Feb 2010 | A1 |
| 20100163890 | Miskin | Jul 2010 | A1 |
| 20100207536 | Burdalski et al. | Aug 2010 | A1 |
| 20110210670 | Sauerlander et al. | Sep 2011 | A1 |
| 20110234114 | Miskin et al. | Sep 2011 | A1 |
| 20120043897 | Miskin et al. | Feb 2012 | A1 |
| 20120069560 | Miskin et al. | Mar 2012 | A1 |
| 20120242239 | Miskin et al. | Sep 2012 | A1 |
| 20120268008 | Miskin et al. | Oct 2012 | A1 |
| 20120293083 | Miskin et al. | Nov 2012 | A1 |
| 20140239809 | Miskin | Aug 2014 | A1 |
| 20140301073 | Miskin | Oct 2014 | A1 |
| 20140301074 | Miskin | Oct 2014 | A1 |
| 20160095180 | Miskin | Mar 2016 | A1 |
| 20170105256 | Miskin | Apr 2017 | A1 |
| 20170188426 | Miskin et al. | Jun 2017 | A1 |
| 20170208656 | Miskin et al. | Jul 2017 | A1 |
| 20170273154 | Miskin | Sep 2017 | A1 |
| 20170295616 | Miskin | Oct 2017 | A1 |
| 20170354005 | Miskin et al. | Dec 2017 | A1 |
| Number | Date | Country |
|---|---|---|
| 1 215 944 | Jun 2002 | EP |
| 08-137429 | May 1996 | JP |
| 11-016683 | Jan 1999 | JP |
| 11-330561 | Nov 1999 | JP |
| 2002008409 | Jan 2002 | JP |
| 2003132708 | May 2003 | JP |
| 2003264090 | Sep 2003 | JP |
| WO 9920085 | Apr 1999 | WO |
| WO 2005048658 | May 2005 | WO |
| WO 2008124701 | Oct 2008 | WO |
| WO 2010106375 | Sep 2010 | WO |
| WO 2016164928 | Oct 2016 | WO |
| Entry |
|---|
| International Search Report for International Application PCT/US2011/036359 dated May 12, 2011, 10 pages. |
| Master Thesis of Srinivasa M. Baddela titled “High Frequency AC Operation of LEDs to Resolve the Current Sharing Problem When Connected in Parallel”. |
| Srinivasa M. Baddela and Donald S. Zinger, “Parallel Connected LEDs Operated at High Frequency to Improve Current Sharing,” IAS 2004, pp. 1677-1681. |
| M. Rico-Secades, et al., “Driver for high efficiency LED based on flyback stage with current mode control for emergency lighting system,” Industry Applications Conference, Oct. 2004, pp. 1655-1659. |
| Robert W. Erickson & Dragen Maksimovic, “Fundamentals of Power Electronics” (Kluwer Academic Publishers, 2nd ed.), p. 576. |
| Written Opinion and International Search Report for International App. No. PCT/US2005/006146, 12 pages. |
| Decision on Institution of Inter Partes Review under 37 CFR 42.108 for U.S. Pat. No. 8,531,118, 47 pages. |
| Patent Owners Preliminary Response under 37 CFR 42.107 for Case IPR2016-01116 for Inter Partes Review of U.S. Pat. No. 8,531,118, 66 pages. |
| Lynk Labs, Inc.'s Initial Response to Invalidity Contentions, Northern District of Illinois Civil Action No. 15-cv-04833, 88 pages. |
| Office Action, U.S. Appl. No. 16/460,790, dated Sep. 26, 2019, 22 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20190116636 A1 | Apr 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61333963 | May 2010 | US | |
| 61284927 | Dec 2009 | US | |
| 61335069 | Dec 2009 | US | |
| 60997771 | Oct 2007 | US | |
| 60547653 | Feb 2004 | US | |
| 60559867 | Apr 2004 | US | |
| 61217215 | May 2009 | US | |
| 61215144 | May 2009 | US |
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