Resistor value for LED

[Kræn]

I got the parts for my first build, an MXR Microamp, yesterday. Still Waiting for the PCB though. Anyway, while waiting I'm doing a lot of reading here. I found this wiring diagram (is that what it's called?) for a 3pdt switch:

http://www.diystompboxes.com/beginner/circswled.jpg

It involves a LED and a 1k resistor. Should this resistor always be 1k?

If not, then what?

Will it be ok to isolate the resistor from the rest of the board just using tape?

Thanks
Christian

[Kræn]

Oh, I just see now that it "varies w. LED". How do I figure this out?

[Gus]

you look at the ma rating of the LED and voltage drop of the led.  Then it is simple the voltage drop of the LED - the power supply divided by the current you want to run the led at = the resistor

Lets take a 9V supply and a a 1k resistor(no led) 9V / 1000 = .009A (9ma)

so if the led has a 1.6V drop the current would be even lower 9VDC-1.6VDC/1000 ohms =  7.4ma

If you have leds that glow bright at low current adjust the resistor for what you want