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70151 Datasheet, PDF (2/4 Pages) OSRAM GmbH – DRAGONtape | |||
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Application Information (continued)
Application Notes
1. Module is intended for use with 350 mA constant current drive condition as is provided by the OT9/100-120/350 and OT9/10-24/350
DIM E (see PIB ECS052R1 for details). The module is not intended for use with constant voltage power supplies, including other OSRAM
LED power supplies.
2. For the white, blue and verde DRAGONtape products, the OT9 power supplies can power up to six LEDs (i.e. one complete module).
For the yellow and red DRAGONtape products, the OT9 can power up to 9 LEDs (i.e. 1.5 modules).
3. Installation of the DRAGONtape must include provision for thermal management to avoid premature failure of the product and to obtain
expected service life. Service life (i.e. lumen depreciation) is primarily a function of LED temperature which is to be monitored on the circuit
board at the designated âTc-Pointâ. (A Tc-Point temperature of 40°C should be sufficient to enable a service life of 50,000 hours for the
white DRAGONtape.)
4. There is no exact installation prescription to obtaining an appropriate Tc-Point temperature because every ï¬xture design is different. In
general, the DRAGONtape module should be adhered to a clean, ï¬at metal surface which has enough surface area to transfer the heat from
the LED to the surrounding air. The metal surface can be part of a conventional ï¬nned heat sink or can be part of the mass of the ï¬xture
itself. A very âballparkâ starting point can be interpreted from the chart below which shows approximate heat sink surface area requirements
for given service life expectations for individual DRAGON LEDs (i.e multiply area values by six for an entire DRAGONtape module).
5. Concerning ï¬xture design, it is important to understand that once heat is transferred to a âheat sinkâ, that heat must still be allowed to
escape the âsystemâ. A heat sink transferring the thermal energy to the inside of an enclosed cavity may ultimately be of little use.
6. The ï¬xture makersâ strategy should be to design a prototype ï¬xture and test that ï¬xture in an appropriate ambient environment while
monitoring the temperature at the Tc-Point which should be allowed enough time to reach thermal equilibrium. In the end, the heat sink
areas from the chart below only represent a starting point for initial design work while the Tc-Point temperature serves as the emperical
test of proper thermal management. Tc-Point temperature can be measured with a standard thermocouple in direct contact with the
circuit board at the Tc-Point or by use of ML4C Series non-reversible OMEGALABELS (www.omega.com) or equivalent.
Approximate Heat Sink Size to Reach Lifetime Targets per LED
(Vertically oriented ï¬at aluminum plate: total cooling surface area equals 2x footprint area)
Service Life to 50% Initial Light Intensity (hours)
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