How to driving 40 3V white LEDs in series

Discussion in 'General Electronics Chat' started by bug13, Jan 9, 2013.

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  1. bug13

    Thread Starter Senior Member

    Feb 13, 2012
    Ok recently I got this cheap white led lamp with magnify glass, all good but when I open it and have a look, the leds are driven directly from 240v main with a resistor, and a bridge rectifier.

    It doesn't look safe, so I'm thinking maybe power it from a 12vdc with a booster converter.

    So should I leave it as it is, or make a boost converter and power it with 12v, is it practical? If not, what are the other options?

    My goal is make it safer to use. (And I want the LEDs last for a reasonal amount of time).

    The LEDs draw about 8mA, 40 in series, and I really don't want to resolder them in parallel :p
  2. Wendy


    Mar 24, 2008
    You use a lot of resistors, and figure what you need for 12V (or 24VDC, or 48V DC). This circuit is not safe, and is in direct violation of AAC Terms of Service

    LEDs, 555s, Flashers, and Light Chasers

    Soldering LEDs in parallel does not work well, this is explained the above link.
    jaygatsby likes this.
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