887 results about "Led driver" patented technology

A LED driver circuit is disclosed that has the ability to drive a single series string of power LEDs. The LED driver circuit uses a single stage power converter to convert from a universal AC input to a regulated DC current. This single stage power converter current is controlled by a power factor correction unit. Furthermore, the LED driver circuit contains a galvanic isolation barrier that isolates an input, or primary, section from an output, or secondary, section. The LED driver circuit can also include a dimming function, a red, green, blue output function, and a control signal that indicates the LED current and is sent from the secondary to the primary side of the galvanic barrier.

A light-emitting diode (LED) driver is adapted to control either the magnitude of the current conducted through a LED light source or the magnitude of a voltage generated across the LED light source. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting the magnitude of the current conducted through the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique. The LED drive circuit may comprise a controllable-impedance circuit, such as a linear regulator. The LED driver may be operable to control the magnitude of the bus voltage to optimize the efficiency and reduce the power dissipation in the LED drive circuit, as well ensuring that the load voltage and current do not have any ripple.

A light emitting diode (LED) lighting system includes a power factor correction (PFC) controller that determines at least one power factor correction control parameter from phase delays of a phase modulated signal. In at least one embodiment, a peak voltage of the phase modulated signal is a PFC control parameter used bit the PFC controller to control power factor correction and generation of a link voltage by a PFC LED driver circuit. The phase delays are related to a peak voltage of the phase modulated signal. Thus, in at least one embodiment, detecting the phase delay in one or more cycles of the phase modulated signal allows the PFC controller to determine the peak voltage of the phase modulated signal.

A LED driver is connectible to several series connected RGB LEDs which connect in series with a current generator. A plurality of LED switches are respectively connectible across one RGB LED. Each LED switch, operating in response to a binary signal is either open to permit electrical current to flow through the RGB LED, or closed to shunt current around that RGB LED. By varying respective duty cycles of the binary signals the LED driver is adapted for controlling operation of the combined RGB LEDs so they emit differing colors of light. An adaptive boost converter LED driver continuously adjusts voltage applied across the series connected RGB LEDs to be only that required for operating those LEDs through which open LED switches permit current to flow.

An AC LED package and circuits are disclosed along with an AC LED driver. The AC LED circuit may include as few as one LED or an array of anti-parallel LEDs driven with AC power sources and AC LED drivers at various voltages and frequencies. The AC LEDs are pre-packaged in various forms and materials and designed for mains or high frequency coupling in various forms to AC power sources, inverter type drivers or packages. The AC LED driver is a fixed frequency driver that provides a relatively constant voltage output to different size loads within the wattage limitation of the driver and in some cases is a direct mains power source.

A light-emitting diode (LED) driver according to the present invention consists of a voltage pre-regulator and multiple linear current regulators with an adaptively-controlled drive voltage. In this LED driver, the efficiency maximization is achieved by eliminating the sensing of the voltage drops across the linear regulators, i.e., by removing the external voltage feedback for the adjustment of the output voltage of the pre-regulator. In the LED driver of the present invention, the self-adjustment of drive voltage is achieved by relying on a relatively strong dependence between the gate-to-source and drain-to-source voltages of a current-regulating transistor, e.g., a MOSFET, operating in the linear region. The driver powers all LEDs in a string with a constant current and provides consistent illumination and optimum operating efficiency at low cost over a wide range of input/output voltage and temperature.

Prior applications disclosed power supply transmission voltage resulting in reduced line losses, with further energy conservation via luminous intensity control (dimming) of lamp(s) including LEDs. Additionally, an invertible, convertable luminaire, and upgraded control module design (comparable to a computer mainframe) comprised of function components including, for example, a microcontroller with programmable CPU, multiple LED driver(s), multiple independent lamp control(s), variable ON time segmentation(s) and variable ramp speed(s), voice actuation (s), security system(s), battery charge component(s), voltage drop (current) limiter(s), protection, ammeter(s), volt and watt meter(s); and voids for optional modules including but not limited to: clock timer(s); photocell(s); motion detector(s) of various function(s); push button(s); programming and function display(s); microphone(s); wireless transmitter(s)/receiver(s); fiber optic interconnection(s); remote control(s); integration to personal computer(s) or other central control system(s); speaker(s); camera(s); irrigation control(s); luminaire mountable laser module(s) and beacon(s); battery array(s); transmission voltage double isolation for nominal 15 volt maximum wet contact.

An LED driver for controlling the intensity of an LED light source includes a power converter circuit for generating a DC bus voltage, an LED drive circuit for receiving the bus voltage and controlling a load current through, and thus the intensity of, the LED light source, and a controller operatively coupled to the power converter circuit and the LED drive circuit. The LED drive circuit comprises a controllable-impedance circuit adapted to be coupled in series with the LED light source. The controller adjusts the magnitude of the bus voltage to a target bus voltage and generates a drive signal for controlling the controllable-impedance circuit. To adjust the intensity of the LED light source, the controller controls both the magnitude of the load current and the magnitude of the regulator voltage. The controller controls the magnitude of the regulator voltage by simultaneously maintaining the magnitude of the drive signal constant and adjusting the target bus voltage.

LED lamp has LEDs aimed rearwards with either a concave mirror to the rear of each LED, or one concave mirror to the rear of two or more LEDs, collecting the light from the LEDs to form a forward projecting beam. LEDs may be high power types that require heatsinking. LED lamp may have a lens forward of each LED to collimate the radiation produced by the LEDs into a beam, where at least one lens has at least one aspheric curved surface. LED lamp may have a transparent reflective optic to collimate the radiation produced by each LED into a beam. For an inspection lamp, the LEDs typically have a peak wavelength of 395 to 415 naometers for seeing the area being irradiated but not so visible as to overwhelm fluorescence of fluorescent materials to be detected. Other wavelengths may be used. LED inspection lamp has a combination of LEDs of different wavelengths or a combination of at least one LED and at least one other light source such that the lamp produces radiation suitable for detection of materials to be detected and adequately illuminates the area being irradiated. LED lamp has LEDs that produce a beam of suitable radiation with a width of 10 degrees or less without additional optics. LED inspection lamp has head attached to a flexible member, with head serving as heatsink for one or more high power LEDs. Current regulator circuits are also disclosed.

An LED down light replacement apparatus is disclosed for insertion into a recessed-light housing can, which includes an LED light source, a means for mounting said LED light source within the housing can, an LED driver circuit electrically connected to the LED light source, a heat sink in thermal contact with the LED light source, and means for removing heat generated by the LED light source. The means for removing heat generated by the LED light source can include a fan and/or ventilation holes in the top of the housing can.

LED driver circuits containing voltage reducing devices, voltage regulating devices, and voltage converting devices are disclosed as the main components to provide power to LEDs. The LED driver circuits are designed to work with a ballast, mains alternating current voltage, direct current voltage, and electromagnetic induction power. The voltage regulating devices can be a resistor in series with at least one zener diode or a voltage regulator both in parallel with and providing power to the LEDs. The LEDs can also be anti-parallel diode pairs consisting of one diode and one LED or two LEDs, or the LEDs can be anti-parallel diode string pairs consisting of diodes and LEDs or all LEDs. The LED driver circuits will be incorporated into LED replacement lamps, and in particular to LED lamps to replace fluorescent lamps for use with existing ballasts and other power sources where the ballast may be removed or bypassed.

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

A buck converter LED driver circuit is provided. The driver circuit includes a buck power stage, a rectified AC voltage source, a voltage waveform sampler, and a control circuit. The buck power stage includes at least one LED and provides a first signal directly proportional to the current through the LED. The rectified AC voltage source is coupled to the buck power stage for driving the buck power stage. The voltage waveform sampler is coupled to the rectified AC voltage source for providing a second signal directly proportional to the voltage provided by the rectified AC voltage source. The control circuit is coupled to the voltage waveform sampler and the buck power stage for turning on and turning off the buck power stage according to a comparison between the first signal and the second signal.

Systems and methods are described that provide an efficient and cost-effective LED driver for controlling strings of LEDs. Embodiments described include an LED driver that comprises an adaptive boost converter and current source that cooperate to provide a desired light output from energized LEDs. Systems and methods are also described that modulate the excitation of the LEDs using a pulsed signal to obtain brightness control. Techniques are described for controlling the operation of individual LEDs in a string of LEDs such that a desired level of light output can be achieved. Embodiments are described in which multicolored LEDs can be included in strings of LEDs and excitation of the individual LEDs can be controlled to obtained a desired color of output.

A luminaire includes an Edison type electrical base, an optic, and a heat sink disposed between the base and the optic. An LED driver circuit is disposed at least partially within the heat sink, and is disposed in electrical communication with the base. An LED assembly is disposed in thermal communication with a surface of the heat sink, and in electrical communication with the driver circuit, the LED assembly includes an LED. The driver circuit includes circuitry that converts an AC signal at the base to a DC signal and provides the DC signal to the LED assembly, the circuitry includes holding current circuitry that produces a holding current for an electrical dimmer disposed upstream of the base in response to a current to the LED assembly being reduced for light dimming purposes.

A configurable light-emitting diode (LED) driver is adapted to control a plurality of different LED light sources, which may be rated to operate using different load control techniques, different dimming techniques, and different magnitudes of load current and voltage. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting either the magnitude of the current conducted through the LED light source or the magnitude of the voltage across the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique, and may be configured using a programming device and a personal computer.

A decorative lighting system includes a command controller, a plurality of illumination devices and a flexible cord interconnecting each. The command controller includes a microcontroller that provides a data signal and a clock signal. The data signal instructs a plurality of addresses corresponding to the lighting devices. Each illumination device has at least three light emitting diodes (LEDs). The LEDs each emit light at a different wavelength than either of the other LEDs. An integrated circuit LED is responsive to the data signal, clock signal, and power signal and drives the first, second, and third LEDs by to a blink rate and intensity. The LED driver includes a plurality of pulse width modulation registers that are selectable in combination to drive the LEDs to a blink rate and intensity independent of one another.

A multifunctional universal LED driver is disclosed that can be configured to match the voltage and/or current requirements of various LED loads such as LED lighting fixtures. The disclosed LED driver replaces the existing wall switch to drive an LED lighting fixture with no need for making changes to the existing wires. The user control means are installed in the faceplate of the LED driver and are relatively accessible to an end user. The configuration control means are installed so as to be relatively inaccessible to an end user during normal operation of the LED driver. In a wireless embodiment, a wireless remote controller operates the LED driver. In another wireless embodiment, the remote controller is a computing platform such as a smartphone, which can configure, operate, and query the status of the LED driver. The status of the LED driver may include on/off, intensity level, energy being consumed by the LED load, configuration settings, and other useful information such as serial number, manufacturing date, country of origin, and ratings. The Wi-Fi embodiment of the LED driver enables the LED driver to be controlled using the Internet and become part of the network of Internet of Things (IoT).

A permanently-installable LED light fixture including a housing including a substantially water-tight chamber, at least one electronic normal-operation LED-driver enclosed within the chamber and receiving power from a general off-location power source during normal operation, an LED assembly secured with respect to the housing, the LED assembly having at least one LED-array module, and at least one backup battery within the chamber capable of providing power during a power outage. In certain preferred embodiments at least one electronic backup LED-driver unit is enclosed within the chamber, the backup LED-driver unit drawing battery power during a power outage.

A recessed LED light fixture without need for a bulky, finned, metal heat sink. The recessed LED light fixture includes a Metal Core Printed Circuit Board (MCPCB) holding an array of LEDs that are arrange at the center thereof, and mounted to the printed circuit board using patterns of electrical and thermal conductors used to conduct a current and radiate heat. A mounting bracket holds the entire assembly for the light fixture together while spacing the LED driver and printed circuit board apart for further cooling, and wherein the upper side of the printed circuit board is exposed to the ambient air inside the housing.

An optical proximity sensor assembly includes an optical proximity sensor with an IR LED emitting light having an infrared wavelength, an IR photo detector sensitive to the infrared wavelength, an optical barrier blocking direct light rays from the LED to the IR photo detector and permitting reflected light rays to reach the at least one photo detector; and an electronic integrated circuit with an amplifier for amplifying a signal detected by the photo detector, an analog to digital converter, LED drivers, noise reduction and ambient light cancellation circuitry, and a digital interface for communication with a microcontroller. The optical proximity sensor is accommodated on a wearable carrier. A single sensor may include a plurality of identical or different LEDs, a plurality of photodiodes, or both. Also, several sensors may be placed on a person's skin along a vascular path to obtain data relating to blood flow and artery stiffness.

A phototherapy or photobiomodulation process employing the application of electromagnetic radiation (EMR) to a living organism, typically a human being. The EMR is generated by one or more strings of LEDs and is programmed to emit one or more wavelengths, typically in the visible and infrared portions of the spectrum, the EMR in each wavelength being delivered in pulses having specified on-times, off-times, photoexcitation frequencies, duty factors, phase delays, and power amplitudes. A system for providing such EMR includes a microcontroller having a pattern library of algorithms, each of which defines a particular sequence of synthesized pulses, and an application pad, preferably flexible, containing the LED strings.

The present invention relates to providing an improved phase controlled dimming LED driver circuitry, system and a method thereof, which is configured to enable dimming intensity of light generated by a light source, said phase controlled dimming driver circuitry being connected to a phase control dimmer that provides to it a regulated alternating current (AC) signal, wherein said phase controlled dimming driver circuitry does not include a microprocessor and pulse width modulates its output current, provided to said light source, at a frequency unrelated to the AC signal frequency. Further, the phase controlled dimming driver circuitry applies amplitude modulation (AM) and pulse width modulation (PWM) substantially simultaneously to the output current provided to the light source.

The present invention provides a liquid crystal display device capable of shortening the time required for stabilizing the brightness and the chromaticity to the temperature change. The input of an LED driver is connected to the output of a PWM controller, so that the electric power supplied to the respective LED groups of red, green and blue are controlled with a PWM method. A feedback control means for controlling the PWM controller includes a brightness setting means, a color setting means, a multiplication means for receiving the outputs from the brightness setting means and the color setting means, a comparison means fed with the output of the multiplication means at one of the inputs thereof, a light sensor temperature compensation means for compensating for fluctuations of the output of the light detection means due to temperature changes, a liquid crystal display panel temperature compensation means for compensating for fluctuations of the spectral transmittance of the liquid crystal display panel due to temperature changes, an addition means for summing the result of detection by the light detection means and the output of the light sensor temperature compensation means, and a multiplication means for multiplying the output of the addition means by the output of the liquid crystal display panel temperature compensation means.

A method for forming a light source includes receiving an LED light module having a plurality of LEDs on a silicon substrate coupled to a flexible printed circuit and bonding the LED light module directly to a heat-sink with a thermal adhesive A base module with LED driver circuits is inserted into an interior channel of the heat sink and contacts of the LED driver circuits are connected to the LED light module.

A system and method for providing a constant current source driver for a light emitting diode string. The converter includes a current sensor that derives feedback signal corresponding to a peak current through the light emitting diode string. The feedback signal is used by a controller to vary a duty cycle of the controller to regulate the average current. The controller is operable to regulate the average current as the number of light emitting diodes is increased and/or decreased.

The invention provides an LED atmosphere illumination control system, which adopts the standard DMX512 control protocol and a bus type network structure. A controller intensively controls all LED lamps. The system comprises an embedded light synchronous controller, an indoor atmosphere illumination controller, a general high-power LED drive, a transmission medium and the LED lamps. The system canperform scene mode control by network control mode, remote control mode, automatic control mode, manual control mode and various control modes; no less than nine scene modes are preset or can be freely set according to individual preference; digital diming can be achieved by an embedded program, and the illumination and the color tone of the light can be controlled precisely; and each lamp can beindependently controlled or can be controlled by networking. The system can ensure the evenness of the illumination effect while achieving the energy-saving illumination control and is widely applicable to local intensive illumination control of public places and families.

An LED driver circuit is provided for protecting one (or more) LEDs connected in series from over-current damages which may result from a short circuit condition. The driver circuit includes a current control circuit for receiving an input signal from a power source and providing a current output for powering the LED. A voltage sensor detects a voltage across the LED. An LED current restriction circuit such as a switching element restricts a current flow into the LED. A short circuit response circuit controls the LED current restriction circuit dependent on a comparison between the voltage detected by the voltage sensor and a predetermined threshold value. When the detected voltage is less than or equal to the threshold value, the response circuit determines a short circuit, and a signal is sent to the current restriction circuit to restrict current flow into the one or more LEDs.

The present invention relates to an LED driver for driving a plurality of light emitting diodes (LEDs), comprising a current controller to control power supply of a predetermined power source unit to make a current flowing in the plurality of LEDs reach a predetermined target current value which sequentially changes corresponding to the respective LEDs; a plurality of divergence switches to flow or interrupt the current with respect to each of the plurality of LEDs; a bypass switch being connected in parallel with respect to the plurality of divergence switches and the plurality of LEDs and to flow or bypass the current supplied to the plurality of LEDs by being open or short-circuited; and a switch controller to sequentially open and close the plurality of divergence switches corresponding to change of the target current value and control the bypass switch to be short-circuited in a range where the current supplied to the LEDs increases, corresponding to the rise of the target current value. Thus, the present invention provides an LED driver which drives an LED in a low voltage to improve light efficiency.

A recessed light fixture includes a thermally protected light emitting diode (“LED”) module. The thermally protected LED module includes a thermal protector positioned in series between a source of electrical power and an LED driver and is configured to open a circuit to prevent power from being supplied by the power source to the LED driver for an LED package when a thermal rating or activation temperature of the thermal protector is exceeded. For example, the maximum operating temperature of the LED driver may be 90 degrees Celsius, and the thermal rating of the thermal protector may be 80 degrees Celsius, and when the temperature of the driver or a mounting bracket upon which the driver is mounted reaches 80 degrees Celsius, the thermal protector opens a circuit and removes current flow from the power source to the driver, thereby removing power to the LED package.