Abstract: An illumination device and method is provided herein for controlling individual light emitting diodes (LEDs) in an LED illumination device, so that a desired luminous flux and a desired chromaticity of the device can be maintained over changes in drive current and temperature. According to one embodiment, the illumination device comprises a plurality of emission LEDs, a storage medium, an LED driver and receiver circuit and a control circuit. The storage medium may store a table of calibration values correlating forward voltage and drive current to chromaticity and luminous flux at a plurality of temperatures for each of the plurality of emission LEDs. The LED driver and receiver circuit may apply respective drive currents to the emission LEDs to produce substantially continuous illumination, and may periodically turn the emission LEDs off to measure operating forward voltages that develop across each emission LED.
Abstract: A controller and method for operating a controller are disclosed. In an embodiment, a method involves in a mode-setting phase, polling connection pins to sense the presence and/or magnitude of a respective relatively high impedance connected between a respective connection pin and a predetermined electrical potential, and/or other connection pins to sense the presence and/or magnitude of a respective further impedance connected between the respective connection pin and a predetermined electrical potential. The method also involves selecting an operational mode from a plurality of possible operational modes. In an operational phase, the method involves operating in the selected operational mode, including providing a respective drive signal having a relatively low output impedance from each of the first group of connection pins, and measuring a sense voltage on each of the second group of connection pins.
Abstract: A driving apparatus and method for a dimmable LED is provided. The apparatus includes a dimmer switch which controls connection or disconnection of an LED series. The apparatus further includes: a boost circuit electrically coupled to the LED series; a comparator electrically coupled to the boost circuit, the comparator receiving a triangle wave signal to generate a PWM signal, the PWM signal controlling the boost circuit; and a RC circuit electrically coupled to the comparator, the RC circuit utilized to output a charging curve signal to the comparator when the dimmer switch disconnects, thereby improving noise and electromagnetic interference of the boost circuit.
Type:
Grant
Filed:
January 22, 2013
Date of Patent:
June 14, 2016
Assignee:
SHENZHEN CHINA STAR OPTOELECTRONICS TECHNOLOGY CO., LTD.
Abstract: A controller for controlling the illumination state of a light source of solid state lighting devices such as LED or OLED assemblies, is presented. The controller controls the light source according to a plurality of illumination states subject to determine an event of a plurality of events. The controller controls a power converter that converts power derived from an input voltage waveform of line voltage power supply into a drive signal for the light source. The controller determines an event of a plurality of events encoded within the input voltage waveform of the line voltage power supply. A first state processor determines a next illumination state of the plurality of illumination states, based on the determined event and based on the current illumination state. Line voltage Switch event detection is performed while no power is available at the line voltage terminals.
Abstract: In various embodiments, a module for providing thermal fold-back protection to an illumination device includes a housing, at least one temperature sensor, and thermal fold-back circuitry.
Type:
Grant
Filed:
June 17, 2013
Date of Patent:
February 16, 2016
Assignee:
TerraLUX, Inc.
Inventors:
Anthony W. Catalano, Anthony N. McDougle
Abstract: An example switched mode power supply includes a timer, a threshold adjust circuitry, a comparator, and a control circuitry. The timer times a duration between crossings of a phase-dimmed signal across a first threshold. The threshold adjust circuitry adjusts a second threshold representative of a desired output of the switched mode power supply, where the second threshold is adjusted responsive to the timed duration between crossings. The comparator compares a feedback signal with the second threshold and generates a comparison result. The control circuitry controls switching of a power switch responsive to the comparison result to regulate the output of the switched mode power supply.
Abstract: An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.
Type:
Grant
Filed:
March 20, 2014
Date of Patent:
October 13, 2015
Inventors:
John L. Melanson, Eric King, Rahul Singh
Abstract: Some of the embodiments of the present disclosure provide a method comprising outputting data at a logic circuit; and in anticipation of a possible change in the data during a data window, applying at least a partial inversion to an output of the logic circuit from a start of the data window.
Abstract: A flash driver to limit a load current for a flash comprises a dc/dc converter (DCDC) having a first input (IN1) to receive an input voltage (Vin) and an output (OUT) to supply an output voltage (Vout). The dc/dc converter is designed to convert the input voltage (Vin) to the output voltage (Vout). Furthermore the flash driver has an adjustable current source (Iadj) connected between the output (OUT) and a load terminal (LT). A first control unit (CTRL—1) is connected to the first input (IN1) and coupled to the adjustable current source (Iadj), and is designed to compare the input voltage (Vin) to a threshold (Vth) and, if the comparison indicates the input voltage (Vin) being smaller than the threshold value (Vth), adjust the adjustable current source (Iadj) such that the input voltage (Vin) is equal or greater than the threshold value (Vth).