wiring multiple leds - pc modding

May 18, 2005 5 Replies

hi i wish to wire 6 (or x number) of the same led, using a psu - 12v line. Most probaly it will be an orange led, thought i should say that as i've read that the actual colour will effect the resistors ..is that so ? So simply whats the best way .... ?



find out the Vforward and Iforward for the LEDs you are going to use

(12 - x * Vf) R = ------------- If

John MexIT: http://johnbokma.com/mexit/ personal page: http://johnbokma.com/ Experienced programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html

thanks.....one thing though could you elaberate on Vforward and Iforward ((If Vf)?!

Put them all end-to-end (in series) and put a 1k resistor in series too. That should light them up with 3.6mA. If you want them brighter, use a lower value resistor, but too low will cause them to fail. The lowest you probably want to go is 220 ohms.

Regards, Bob Monsen

Those values are given in a datasheet. Vf is different for LEDs with different colours. If is often around 20 mA, but look it up.

E.g.

formatting link

Vf = 1.7 If = 20 mA

( 12 - 6 * 1.7 ) / 0.02 A = 90 Ohm.

So use a 100 Ohm resistor in this case.

John MexIT: http://johnbokma.com/mexit/ personal page: http://johnbokma.com/ Experienced programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html

Hence: look up Vf and If, and *calculate*

John MexIT: http://johnbokma.com/mexit/ personal page: http://johnbokma.com/ Experienced programmer available: http://castleamber.com/ Happy Customers: http://castleamber.com/testimonials.html

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required