3 LED's in parallel = same voltage?

[Über~PhLuBB]

I'm gonna be modding my GameCube (Don't start, I'm not abandoning PC modding or anything), and instead of poking around with a multimeter trying to find a 3 volt power source for these LEDs, what if I ran all 3 in parallel off of the amber power light's contacts? Would that work? What are the potential ramifications? I havn't taken an electronics course yet, so I wouldn't know an ampere from a watt.

[Diggrr]

Here's some clarification for you to use.

Take 3 diodes, all rated for 2.5 volts and 100 milliamps.

In parallel, they'd need 2.5 volts and 300 milliamps to work.
In series, they'd need 7.5 volts and 100 milliamps to work.
You can add more diodes to closely equal the voltage you'll be using (eg..8 diodes in series would run on 20 volts without any resistors. 2.5 volts X 8 led's = 20 volts needed)

Also with led's you can over power or underpower them by .25 volts without a problem, incase you can't match the number of diodes to the voltage you're hooking up to.

And one more thing, diodes do not work like lightbulbs in that you cannot hook them up backwards...they will not work if you switch + and -. So line them up in the same direction. Many have one leg longer than the other to tell + from -, and many have a tiny flat spot on the side of the base to show you the orientation.

Hope this helps

[Über~PhLuBB]

Originally posted by Diggrr
Here's some clarification for you to use.

Take 3 diodes, all rated for 2.5 volts and 100 milliamps.

In parallel, they'd need 2.5 volts and 300 milliamps to work.
In series, they'd need 7.5 volts and 100 milliamps to work.
You can add more diodes to closely equal the voltage you'll be using (eg..8 diodes in series would run on 20 volts without any resistors. 2.5 volts X 8 led's = 20 volts needed)

Also with led's you can over power or underpower them by .25 volts without a problem, incase you can't match the number of diodes to the voltage you're hooking up to.

And one more thing, diodes do not work like lightbulbs in that you cannot hook them up backwards...they will not work if you switch + and -. So line them up in the same direction. Many have one leg longer than the other to tell + from -, and many have a tiny flat spot on the side of the base to show you the orientation.

Hope this helps

Let's say hypothetically that the existing LED is 300miliamps. I could remove it, and use 3 100 miliamp LEDs in it's place, in paralell without a problem, right?

How could I find the miliamp potential and voltage of the LED that's in there now, so that I might purchage new LEDs which would work properly?

[Diggrr]

The amperage depends solely upon the diode, not the power supply. The diode draws the amperage from the power supply, the powersupply doesn't push the amperage through it. A little hard to explain, really. Basically, the psu pushes the voltage, and the device (led in this case) sucks the amperage.

All you need to know to replace an existing diode is it's voltage, which you can find by just measuring across the solder pads with a dc voltmeter (with the power turned on, diode lit up). Usually most diodes are around 2.2-2.5 volts, so most diodes would work. (but you should check to make sure.)

[Diggrr]

You can check a diodes amperage draw by disconnecting one of the wires, and placing your digital meter across the circuit (represented by the blue). Again, the power would have to be on, and the diode lit up.

Also you can put in multiple smaller diodes in place of one large one if you'd like.

*edit* dig my l33t paint shop pro skilz!...sorry, just had to use that word once.

[Über~PhLuBB]

So if the sum of the amperage of all 3 smaller diodes is equal to the larger one, as well as the voltage of each of the smaller diodes (but not the sum of) is equal to the larger one (in parallel), then all is well, and I won't end up burning out any of the diodes (hopefully)?

[Diggrr]

That's correct! Have fun tearing into it!

[Hoot]

Keep in mind that the amount of light an LED emits (Milli-Candle-Power) varies from one LED to the next. Even LEDs that draw the same amount of current for a given voltage, will not automatically all have the same brightness.

Here's a good LED reference:

http://ledmuseum.home.att.net/reserved.htm

Hoot

[Über~PhLuBB]

Brightness isn't nessecarily important. I don't need a 30,000mcd diode, it's not gonna be a console/flashlight. =)