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Author Topic: constant voltage leds  (Read 963 times)

Dueller

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constant voltage leds
« on: February 13, 2010, 01:35:50 PM »

Hi,

Just in case there are modelers that dont want the hassle of working with leds and resistors, this might help, although slightly more expensive, you can fit any led to the unit.

http://www.maplin.co.uk/Module.aspx?ModuleNo=47458

lee
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malcolmfrary

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Re: constant voltage leds
« Reply #1 on: February 13, 2010, 02:21:30 PM »

More correctly, its a constant current LED module which works to a wide range of voltages, albeit at a price.  LEDs are intrinsically constant voltage devices, or at least, they do their best.  They often get used as a reference in regulator circuits, since the act as low voltage zeners, and have the additional benefit of lighting up to let you know that something is happening.
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wombat

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Re: constant voltage leds
« Reply #2 on: February 19, 2010, 08:02:18 PM »

A lot of money to save a quick calculation - two pounds or more plays 20p or less.

Rule of thumb - 5V use 220R 12V use 1K.  If you need to match the intensity of red and green LEDs you need approximately 2 times the current through the green LED - use half the resistance.

Wom
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