Steve_T

Hi I have a 12vDC transformer and when i put my meter accross the poles its showing 15v? anyone have any idea why? Anyway back to the question in hand. I have calculated that i will need a 470ohm resistor to connect to my led too but it appears to be slowly getting duller and duller. The led spec is as follows: Color: Blue Size: 3mm MCD: 5000-7000 Viewing angle: 20 Forward Voltage: 2.8-3.2 Forward current: 20-30 mA Does anyone know why this is happening? Thanks Steve