摘要:
An LED-based lighting system is operated with a time-based process. The LEDs are first turned on by energizing the system at full power. After a predetermined time period, which is selected so that the junction temperature of the LEDs does not reach a critical temperature, the current supply is ramped down to a steady-state supply. The steady-state current is maintained as long as the light is turned on. When the light is turned on the next time and the LEDs have not cooled down all the way, as determined by the time that has expired since the LEDs were last lit, the full-power time period is shortened accordingly.
摘要:
The invention relates to a device (1) for switching a lamp (2, 3) on and off that is controlled by a digital control input DALI. According to the invention, a load current monitoring is ensured.
摘要:
An inverter controller dives an inverter to operate at a switching frequency selectively from one of a preheating frequency (f1), a starting frequency (f2), and a lighting frequency (f3) which are different from each other, thereby giving a preheating mode, a starting mode, and a lighting mode. A reset means is provided to make the starting mode upon lowering of a voltage supplied to the inverter below a first threshold, while an inverter stop means is provided to stop the inverter upon detection of abnormality of a discharge lamp. A timer generates a signal determining the start of the preheating, starting, and/or lighting modes, and generates a reset signal disable signal for disabling the reset means, an inverter stop disable signal for disabling the inverter stop means. The inverter controller includes a frequency sweep means for varying the switching frequency gradually from the starting frequency to the lighting frequency. The timer disables the reset means only during a period starting from the selection of the preheating frequency and ending when the switching frequency varies to the lighting frequency, and disable the inverter stop means only during a period starting from the selection of the preheating frequency and ending when the switching frequency begins to vary from the starting frequency to the lighting frequency.
摘要:
An electric discharge lamp has an arc tube within an outer gas filled glass envelope, and a thermal switching means is located within the outer envelope. The thermal switching means has a bimetal strip and a spring-like member each affixed to at least one of the electrical conductors, and upon application of heat the bimetal strip and spring-like member are flexed to short-circuit the electrical conductors and remove any DC potential between the main electrode and the starting electrode minimizing electrolysis.
摘要:
A high intensity discharge lamp having a hermetically sealed envelope with support wires therethrough has an arc tube therein with support wires whereby a starter device having first and second contacts of a normally-closed switch has a first bimetal coupling the first contact to one support wire and a second bimetal coupling a second contact to another support wire with the bimetals positioned to flex in opposite directions and enhance the operation of the contacts and of the high intensity discharge lamp.