wiring in an LED

macmodder · 2 Feb 2011 at 22:44

I'm making a custom case as a project, but I have very little experience with electronics (wiring, soldering etc.) I want to wire in my own LED, but I'm unsure if what I am thinking is the correct way to do it.

I'm thinking of getting a bog standard 5mm LED

Can I simply connect (I guess that means solder) the cathode/anode to the corresponding pins on a 2 pin extension cable?

Is that a runner?

stulid · 2 Feb 2011 at 22:53

extension cable from where? you dont want to put more volts/amps through the LED than it can take.

geuben · 2 Feb 2011 at 22:58

Assuming you mean to wire it to a motherboard header designed for LEDS. i.e POWER_LED, or HDD_LED or something, then you shouldn't have any problems just wiring it straight up.

Danny091 · 2 Feb 2011 at 23:04

Remember to put it the right way around! I melted a lot in electronics for the lulz.

PhillyDee · 2 Feb 2011 at 23:36

Whats it for?

If its for illumination, you will also need to wire in the correct value of resistor. It must be connected he correct way around, and also to the correct wires.

EniGmA1981 · 3 Feb 2011 at 06:30

geuben said:
Assuming you mean to wire it to a motherboard header designed for LEDS. i.e POWER_LED, or HDD_LED or something, then you shouldn't have any problems just wiring it straight up.

That's a pretty cool idea actually... might rig up my bottom LED strip to the HDD led so it flashes when it's reading

Tealc · 3 Feb 2011 at 08:35

A 470 ohm resistor would suit most applications when taken from a 12v source, this is usually the resistor they ship with LEDs off ebay.

If wiring from a 5v source you need about 75 ohms - 150 ohms depending on the colour.

Here's one wired up.....I usually wire the long leg to the resistor but it is not critical. What is critical is that the positive source is wired to the long (Anode) leg.

You will also notice that the LED has two elements, a small one and a large one. It is the small one that is the Anode and the larger one that is the Cathode.

EniGmA1981 said:
That's a pretty cool idea actually... might rig up my bottom LED strip to the HDD led so it flashes when it's reading

That'll be annoying after two minutes. Hope you wire a switch in there mate so you can switch ot off.

macmodder · 3 Feb 2011 at 09:06

Thanks all, you've given me plenty to think about. I think I'll go away and do some more reading before attempting this, but thanks a lot for the advice.

DWorrall · 3 Feb 2011 at 09:09

When i use LED's i buy a set of 12v LED christmas lights, cut them up and use those... They're usually 3V each so a string of 4 is enough for the 12V line inside of a computer... putting 3 makes them brighter but cuts their life span.