摘要:
A device, system and method to drive light emitting diodes (LEDs) are disclosed. An exemplary system may include a string of LEDs coupled across a voltage source configured to provide an input voltage. The string of LEDs may include a plurality of separate groups of LEDs and a plurality of switch circuits. Each of the switch circuits may include a switch coupled in parallel with an associated one of the groups of LEDs to control current flow through the associated group of LEDs in response to a control signal from a controller circuit. A switch protection circuit may be associated with at least one of the switches. A steering circuit may also be coupled in series and associated with each of the groups of LEDs.
摘要:
A device, system and method to drive light emitting diodes (LEDs) are disclosed. An exemplary system may include a string of LEDs coupled across a voltage source configured to provide an input voltage. The string of LEDs may include a plurality of separate groups of LEDs and a plurality of switch circuits. Each of the switch circuits may include a switch coupled in parallel with an associated one of the groups of LEDs to control current flow through the associated group of LEDs in response to a control signal from a controller circuit. A switch protection circuit may be associated with at least one of the switches. A steering circuit may also be coupled in series and associated with each of the groups of LEDs.
摘要:
A phosphor blend for use with an indium halide discharge lamp and a lamp made therewith is described. The phosphor blend comprising at least two phosphors selected from Ca8Mg(SiO4)4Cl2:Eu, SrSi2N2O2:Eu and Ca2Si5N8:Eu: The blend may also include a blue-emitting phosphor such as BaMgAl10O17:Eu.
摘要翻译:描述了与卤化铟放电灯一起使用的荧光体共混物和由其制成的灯。 包含至少两种选自Ca 3+(SiO 4)4 Si 2 O 3:Eu的磷光体的荧光体共混物 ,SrSi 2 N 2 O 2:Eu和Ca 2 Si 5 N Eu:共混物也可以包括发蓝光的荧光体,例如BaMgAl 10 O 17:Eu。
摘要:
In one embodiment, the present disclosure provides a method for controlling a plurality of LED channels. The method includes receiving an LED brightness signal having a plurality of superimposed pulse width modulated (PWM) brightness signals each having a duty cycle and amplitude at a unique modulation frequency, each PWM brightness signal being proportional to the brightness of a respective LED channel. The method also includes determining a pulse area of each PWM brightness signal at each respective unique frequency. The pulse area is proportional to the product of the amplitude and the duty cycle. The method also includes generating pulse area signals proportional to the respective pulse area and comparing the respective pulse area signals to user defined and/or preset photometric values to generate respective error signals proportional to the difference between the respective pulse area signals and the user defined and/or preset photometric values.
摘要:
A fluorescent lamp comprises a glass tubular body defining a discharge space, and first and second electrode assemblies mounted in the discharge space in opposition to each other, each of the electrode assemblies comprising a first electrode and a second electrode. Each of the first electrodes comprises a metal lead wire with an electron-emitting material disposed on a free end thereof, and each of the second electrodes comprises a cup-shaped tube coaxially surrounding one of the first electrodes and the electron-emitting material disposed on the first electrode. The second electrode tube and the electron emitting material therein form an annular gap therebetween.
摘要:
A pulse-excited mercury-free lamp system, and method of sustaining the emission of light emission from such a lamp, is provided. The system includes a light-transmissive envelope having an inner surface and a phosphor layer coated thereon. A discharge-sustaining gaseous mixture of a noble gas, at a low pressure, and a metal halide, is retained inside the light-transmissive envelope. An electrical system provides a plurality of pulses to the discharge-sustaining gaseous mixture, resulting in a discharge, which causes the lamp system to emit light. The emission of light is maintained by turning the discharge on during a pulse width of each pulse in the plurality of pulses and by turning the discharge off during a remainder of each period in the plurality of pulses. Particularly in systems where the metal halide is indium-based, this maintains an efficient emission of light without the use of mercury.
摘要:
A light emitting diode (LED) controller for controlling a plurality of LED channels includes channel select circuitry, detection circuitry, and error processor circuitry. The channel select circuitry is configured to drive N−1 LED channels of a plurality of (N) LED channels at a nominal modulation frequency and to selectively drive a selected one of the N LED channels at a probe modulation frequency. The detection circuitry is configured to receive a composite brightness signal corresponding to brightness signals from the N LED channels. The detection circuitry is further configured to filter the composite bright signal and generate a selected brightness signal corresponding to a brightness of the selected LED channel at the probe modulation frequency. The error processor circuitry is configured to compare the selected brightness signal to user defined and/or preset photometric quantities and generate a control signal for adjusting the brightness of the selected LED channel.
摘要:
A light emitting diode (LED) controller for controlling a plurality of LED channels includes channel select circuitry, detection circuitry, and error processor circuitry. The channel select circuitry is configured to drive N−1 LED channels of a plurality of (N) LED channels at a nominal modulation frequency and to selectively drive a selected one of the N LED channels at a probe modulation frequency. The detection circuitry is configured to receive a composite brightness signal corresponding to brightness signals from the N LED channels. The detection circuitry is further configured to filter the composite bright signal and generate a selected brightness signal corresponding to a brightness of the selected LED channel at the probe modulation frequency. The error processor circuitry is configured to compare the selected brightness signal to user defined and/or preset photometric quantities and generate a control signal for adjusting the brightness of the selected LED channel.
摘要:
A fluorescent lamp comprises a glass tubular body defining a discharge space, and first and second electrode assemblies mounted in the discharge space in opposition to each other, each of the electrode assemblies comprising a first electrode and a second electrode. Each of the first electrodes comprises a metal lead wire with an electron-emitting material disposed on a free end thereof, and each of the second electrodes comprises a cup-shaped tube coaxially surrounding one of the first electrodes and the electron-emitting material disposed on the first electrode. The second electrode tube and the electron emitting material therein form an annular gap therebetween.
摘要:
A pulse-excited mercury-free lamp system, and method of sustaining the emission of light emission from such a lamp, is provided. The system includes a light-transmissive envelope having an inner surface and a phosphor layer coated thereon. A discharge-sustaining gaseous mixture of a noble gas, at a low pressure, and a metal halide, is retained inside the light-transmissive envelope. An electrical system provides a plurality of pulses to the discharge-sustaining gaseous mixture, resulting in a discharge, which causes the lamp system to emit light. The emission of light is maintained by turning the discharge on during a pulse width of each pulse in the plurality of pulses and by turning the discharge off during a remainder of each period in the plurality of pulses. Particularly in systems where the metal halide is indium-based, this maintains an efficient emission of light without the use of mercury.