Leds? 12v

Hi I’m new to this forum and just about to build my first shruthi, I wanted to change the leds… I know from the website that you have to change the resistors for different brightness and colour of leds but I wanted to know if the 12v ones will work with it, I’ve bought some off ebay but later realised they said 12v supply on them?
Any help would be great :slight_smile:

Shouldn’t be an issue but you’ll need to experiment a bit with the resistors. You can calculate the resistor values but I’m too stupid for that so I put in a socket where the resistors would usually be, and then I can temporarily try one resistor and see how the LED looks.

Post a link to the eBay auction where you got the LEDs so we can have a look.

12V LEDs? Probably they have a built-in resistor? Link please!

It will be hard to power 12v LEDs when the Shruthi runs on 5v :P. A link to the LED datasheet or ebay page would be helpful.

Sorry guys it was my bad lol I read the description wrong :-(, there actually 3.2-3.8 900mcd brightness ones, sorry got the confusion, there the night components ones on ebay, does anyone have an idea of the best resistor to use with them, would 1k but ok?
Thanks again

900 mcd is a lot… I’d go for 10k first

Can you point to the actual datasheet or specifications?

There are actually LEDs designed to be powered straight from the rails. They have a built-in current-limiting resistor. If you have such a LED, there’s no hope to use them with the Shruthi because the current-limiting resistor is already too much.


here it is guys, I appreciate your help :slight_smile:

I assume you have the blue ones? 9000 mcd and not 900? … Best thing would be to try one led on a 5V source with a led… You could use the shruthi filterboard for that if you don’t have something else…
Go for about 10k first. Maybe even 15k
1k will make them retina burning bright.

No internal current limiting resistor, so you should try 10k. Experiment!

That’s why I use the socket. Great for experimenting and doesn’t get in the way when you’re done.

Need help guys can you check my help topic :frowning: