5 Important Factors When Buying LED Drivers Individual8 months ago - Land - Chennai - 127 views
WILMINGTON, Mass.--(BUSINESS WIRE)--Jul 31, 2017--Osram, a leading global lighting and technology company, today announced its OPTOTRONIC®Dual-Mode Programmable Emergency LED Driver, the market’s first programmable single-driver solution for emergency Solid State Lighting fixtures, which offers the ability to program and customize the light output in both normal and emergency operations.A separate snap-on battery pack with harness, available in slim, linear and compact options, powers emergency lighting in the event of an outage and provides up to 18W in back-up mode. The complete solution reduces the number of components required per emergency luminaire, substantially simplifies in-fixture wiring, and enables OEMs to better tailor their fixtures to application requirements while reducing the number of SKUs they must inventory.
Industry’s First Dual-Mode LED Driver with Programmable Emergency Light Levels Offers OEMs Greater Flexibility, Simplifies Manufacturing (Photo: Business Wire)
“Emergency lighting luminaires typically require a dedicated emergency driver, a dedicated LED driver and numerous wiring connections, creating a complex manufacturing process and often compatibility issues for OEMs,” said Tom Shottes, Head of Osram Digital Systems, Americas Region. “Osram’s new OPTOTRONIC® Programmable CE Emergency LED Driver combines the emergency and standard LED drivers into one solution, addressing key issues experienced by OEMs. The ability to program and tailor the light output in both standard and emergency mode offers additional value and flexibility in designing emergency lighting fixtures.”
The National Fire Protection Association’s code has a minimum requirement of one foot candle of light on the ground for at least 90 minutes to allow people to safely and efficiently exit a building in the event of an emergency. A programmable emergency driver solution enables OEMs to support customers with tailored and optimized emergency led driver accessories, irrespective of the building architecture, space and lighting plans.
The lamp inrush current on switching LEDs has become an area of concern in the lighting industry. ‘Inrush current’ of the LED drivers refers to the input current of short duration that flows into the LED driver, during the initial start-up, to charge the capacitors on the input side. Typically, this is a short duration current, whose amplitude is much greater than the operating or steady-state current. The inrush current is due to the EMC filter on the input and bulk capacitor on the boost circuit this is inherent to the LED technology.
The figure shows the nature of the inrush current and its peak, IMAX. T50 is the time duration in which the inrush current pulse is equal to 50% of IMAX. It shows an example of inrush current (IMAX) and T50 times for a typical LED driver.
If there are a number of LED drivers in an LED Luminaire, and if there are a number of such LED Luminaires on one circuit, the max peak inrush current and it’s duration may be additive. However, it is not an exact mathematical calculation; i.e. for “N” drivers connected in parallel does not equal exact “N” times the inrush current for one driver or N times the T50 time for one driver. It depends on the impedance of each driver and the line impedance.
The line impedance has a significant effect on the peak and duration of the inrush current. Transformer type and size, wire size, length of runs, and other devices in the circuit path are a few things that could lead to high impedance.
The inrush current and the duration of the LED driver differs from manufacturer to manufacturer and from model to model. As this current duration is very small, sophisticated instruments with very high sampling rates need to be used for exact calculations. The inrush current also depends on the exact moment of switching, during the alternating cycle.
For a typical 150W, 0.7A LED driver, Philips Model 9137012116, used in various CREE luminaires, the inrush current is stated as 130Amp for 165 Micro Seconds. It is suggested that up to 7 -10 of these drivers be used / per 20A C curve MCB, however it will depend on the individual circuit impedance.
For a typical 220W, 1.05A LED driver, CREE Model LE098X01 used in CREE High Output Edge luminaires, the inrush current is stated as 80 Amp for 1000uS (1mS). It is suggested that up to 6 – 8 of these drivers be used /per 20A C curve MCB, however, it will depend on the individual circuit impedance.