AC 240v filament LED driver

218

03:49:47

I am attempting to run 4 x 50v 15mA LEDs from a 240v ac source. Does this seem right? I'd use less than 10k resistors for the load but I'd be concerned the wattage would shoot up and it start getting too hot. I've used 2 x100ohm resistors prior to rectifying to keep the inrush current low.

published 10 years ago

hurz

10 years ago

A few weeks ago i bought one 4Watt 230V. I read on wiki each filament contains 28 leds. There are 4 filaments. Suppose they are all in series that would make around 3V for each at 325V peak. I should open it to check whats inside ;-) i do not expect a big capacitor and also no big resistors in size or value. Your 10k for example would burn 2.25W at 15mA! This is definitive not economic.

obsidian_eclipse

10 years ago

Wouldn't the wattage be distributed between the two resistors as they are acting in series? I will check the leds though thanks

hurz

10 years ago

Yes it will double from 2.25W to 4.5W. P=I^2*R but the point is ; you dont even get 15mA. Anyway, lets find out what clever Chinese engineers put in such a filament LED.

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