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Dear Gentleman. My name is Silvio Hideo Ishizawa. I'm planning to use component NSIC2050JB to drive 30 LEDs (LSE6SF from Osram). With simulation from ON site using AC line with 100V to 130V it is require just 30 LEDs and one resistor of 1.0mOhm. However I need to have these LED supplied with full AC range (100V to 240V). I would like receive suggestions to have these LEDs supplied with 100V to 240V automaticly. I'm looking forward receive your attention. Thank you. Silvio Hideo Ishizawa
It is fairly easy to maintain the same output power (same amount of light) across the input range, but what would vary drastically is the input power, and hence efficiency. 30mArms through LEDs can be done easily at voltage range, but 240V*30mA is from the starting gate double what 120V * 30mA.
We have circuits that will take the power dissipation off the CCR so the circuit will still run properly at high line, but otherwise, with a limited number of LEDs, the efficiency will be poor, at high line especially. It is not possible with a linear driver to maintain the same input and output power with one string of LEDs.
Were the customer using, say 60 LEDs, we could make something that throttles the current at high line and does a parallel-to-series action on the LEDs for improved efficiency (still less expensive than an SMPS) but it’s fundamentally the same problem still—constant current regulation to the LEDs without some sort of isolation transformer element means you have double the power draw at high line.
This is an inexpensive but low performance solution. SMPS is traditionally the route for UPS design.
Answered by: ON Semiconductor
2014-08-08 06:35:03.823