摘要:
The present invention provides a lighting fixture (108) including a light source (104), a light source controller (110, 112), and an external controller plug. The light source controller (110, 112) controls power to the light source (104). The external controller plug (106) allows an external controller (114) to selectively engage a power source (102) to the light source controller (110, 112).
摘要:
A simple and effective technique for reducing an external magnet flux emitted from a driven inductor (19) surrounded by an ionizable gaseous medium (15). This technique includes surrounding the inductor (19) with at least one shielding conductive loop (23), terminating the shielding loop in a capacitive termination (24) to resonate, and maintaining a resonant frequency of the capacitive termination (24) in series with an inductance of the shielding loop (23) below the predetermined driving frequency of the inductor (19).
摘要:
Techniques are disclosed for dimming LED strings using frequency modulation (FM) dimming and burst control dimming. At high brightness levels, FM dimming may be used to decrease the current through LED strings by increasing the switching frequency of pulses within a pulse train of an AC current source. At low brightness levels, or after the switching frequency has been increased to the resonant frequency of the current source, burst control dimming may decrease the current through LED strings by decreasing the duty cycle of the pulse train of the current source. At high brightness levels, FM dimming and burst control dimming may be combined by decreasing the duty cycle of the pulse train at each of a number of increasing switching frequency values. FM dimming may also be combined with frequency hopping in order to increase the number of available frequency steps.
摘要:
The present invention provides a lighting fixture (108) including a light source (104), a light source controller (110, 112), and an external controller plug. The light source controller (110, 112) controls power to the light source (104). The external controller plug (106) allows an external controller (114) to selectively engage a power source (102) to the light source controller (110, 112).
摘要:
Techniques are disclosed for independent control of individual LED strings driven from a single AC current source. A lighting driver circuit includes a DC-AC inverter with series resonance that provides a current that may be split into multiple currents for driving multiple LED assemblies (LED1, LED2, LED3). Current splitting transformers (T1, T2, T3) may be used to divide the current from the AC source, and the amplitude of the current from the AC source may be determined by a microcontroller. In some cases the current splitting transformers provide galvanic isolation to the LED assemblies. The multiple LED assemblies may be controlled by a number of switches (S1, S2, S3) that may independently activate the individual LED assemblies based on the duty cycle of multiple PWM signals provided to the switches by the microcontroller. When all of the PWM signals output from the microcontroller are in an off-cycle, the current source may be turned off.
摘要:
A lamp assembly adapted to operate as one of a total number of lamp assemblies that are connected together in series and connected to a ballast. The lamp assembly comprises an electrodeless, closed-loop, tubular lamp envelope enclosing mercury vapor and a buffer gas, and a transformer core disposed around a portion of the lamp envelope. An input winding is disposed on the transformer core so that it has a particular number of turns, N input . An auxiliary winding is disposed on the transformer core so that it has a particular number of turns, N auxiliary . The auxiliary winding is adapted to connect to the ballast and to couple with the input winding. The ratio of the particular number of turns N input to the particular number of turns N auxiliary is substantially proportional to the total number of lamp assemblies that are adapted to operate in series together.
摘要:
Techniques are disclosed for independent control of individual LED strings driven from a single AC current source. A lighting driver circuit includes a DC-AC inverter with series resonance that provides a current that may be split into multiple currents for driving multiple LED assemblies (LED1, LED2, LED3). Current splitting transformers (T1, T2, T3) may be used to divide the current from the AC source, and the amplitude of the current from the AC source may be determined by a microcontroller. In some cases the current splitting transformers provide galvanic isolation to the LED assemblies. The multiple LED assemblies may be controlled by a number of switches (S1, S2, S3) that may independently activate the individual LED assemblies based on the duty cycle of multiple PWM signals provided to the switches by the microcontroller. When all of the PWM signals output from the microcontroller are in an off-cycle, the current source may be turned off.