July 3rd, 2012, 09:48 AM
I have built two gadgets - one a two button channel change footswitch and one a simple pedal with a volume pot I can switch on or off.
I need to put brighter LEDs in as we are playing lots of outdoor gigs in sunshine and I can't see the current LEDs at all.
As I am total newbie to pedal building, is there anything I need to check spec-wise when buying LEDs for standard 9V applications like this? Or will just about any LED of the right physical size work in a 9V setting?
July 3rd, 2012, 09:55 AM
You'll need to add a resistor to limit the current to the LEDs, otherwise they will burn out. I usually use a 2.2K resistor, but other values will work too, although I don't think I would go any lower.
July 3rd, 2012, 10:17 AM
Thanks Pat. So are you saying any LED will be fine as long as there's a resistor there?
July 3rd, 2012, 10:26 AM
I like these with a 2.2K resistor on the anode leg - one of my customers calls the LEDs "eye poppers."
July 3rd, 2012, 10:31 AM
Most LEDs will burn out immediately if you run them at 9V, so a current-limiting resistor is usually a must. Chances are, you used current limiting resistors in your builds(?). If so, you can adjust the value of your resistors down to make the LEDs brighter. Like suproman said, a 2.2K resistor is a good starting point. You can probably go down as low as 1k without burning out the LED (but don't quote me on that!).
All that said, some modern LEDs are much brighter than others, even with the exact same current limiting resistor in place.
Any other info you can provide on your builds would be helpful. Like what value resistors do you currently have installed? What size are your LED's (3mm or 5mm)?. Are they "water clear" LEDs, or opaque colored? And what color are they? Some pics would help as well.
July 3rd, 2012, 02:36 PM
You need to know the current-handling limit of the LED you're using to know what resistor value you need to use. For the LEDs I use, 2.2K is the smallest-value resistor I can get away with - I want 'em bright.
July 3rd, 2012, 02:51 PM
You could put a 1Watt Luxeon LED in there, but you may actually burn your eyes out if you look directly at it. :-)
July 3rd, 2012, 03:58 PM
You can get 'superbright' or similar LEDs that will happily scorch your retinas at 9v. I use these (http://www.rapidonline.com/Electronic-Components/Ospw5111a-5mm-White-LED-6000mcd-55-1820/?sid=c7ac4fa7-922e-423a-8109-8576561a633c) in one of my pedals. With a 15K resistor, you'll wish you hadn't looked directly at it :cool:
July 5th, 2012, 01:35 PM
Thanks for the help folks.
They are 3mm LEDs that are red and green rather than water clear.
The channel changing pedal has resistors in, so I guess I'll work out the value and try something else, or just use what's there and try another LED.
The 'volume knob' pedal doesn't have a resistor so maybe I'll put one in to be on the safe side.
Thanks Rackham for the link to a UK supplier for LEDs you have used.
July 5th, 2012, 02:46 PM
Some LED have built in ballast resistor come don't.
For the extra bright things, check out car workshop inspection lamps. DRL units and car LED replacement "bulbs".