Can someone confirm that the aquaero RGB led header is 4.5v?

Second to that, can someone provide a part number for a common cathode diffused LED that will take that voltage. Seems like a strange voltage.

I had all colors at full tilt and that's what I measured. I'd like to use a diffused LED as the one provided separates colors a bit and doesn't mix very well.

I did see that, but that being the case, 3-4 isn't 4.5. Can't say I've run into too many LEDs, in particular RGB ones with a >2.1v red element.

I've got some diffused common cathode LEDs already that are rated for 1.9, 3.1 and 3.2v respectively. I suppose I can toss some resistors on, but I'd rather find what their P/N is and find a diffused variant.

AC guys...any input? I can't imagine an LED is a closely guarded secret.

Fair enough.

Well, it seems it doesn't matter. I had some spare diffused LEDs and just give it a go, and it's all good. Dunno why my multimeter was reading 4.5v...oh well.

The reading was taken unloaded, and for this voltage, any controller worth anything would hold its voltage weather loaded or not. Certainly shouldn't show a difference over a volt and an LED wouldn't cause that kind of drop.

Well, that's not entirely true. Eg I have an LED rated at 2.1v, 50mA. All that means is it will be a dimmer LED on this controller. No biggie. But I can put it on a circuit that could provide 20A at 2.1V and all that LED will draw is 50mA. For some LEDs in this respect, you don't need to worry about current limiting designs. I gave it half an amp and it was happy as it could be.

I have another LED that will eat 300mA+ at 2.2v and will eventually cook itself. It ultimately depends on the LED.

It's sometimes for the protection of LEDs. And heat. Perhaps it's a trade off in the design of the circuit as well.

Voltage kills LEDs in this first example. Not amperage. Well, heat does to, hence limiting the amperage to LEDs controls the heat of said LEDs.

But this goes way OT. The issue was why my voltmeter was reading such high voltages. But it's a non issue now as my question was answered and that makes sense.

I got that part, Sebastian, I was just saying that from a general perspective in terms of what LEDs can/can't handle.

I was just saying that in a case of a particular LED that I have, I can drive it at 2.1v and delimit the amperage and all is right with the world.

With the RGB LED I have, it's rated at 1.9, 3.2, and 3.3V for RGB respectively at a max of 30mA. I don't see this being an issue.