I'm building this simple LED driver from here (http://led.linear1.org/a-cheap-current-regulated-luxeon-star-driver-design/):
I haven't 3.9Ohm, 0.5W resistors, so I used 3 in parallel 12 Ohm, 0.25 resistors at first (12/3 = 4, 1,25/3 = 310mA) . The measured current was about 310mA as it should be.
Next day I've bought 0,5W resistors labeled as (orange/white/gold/gold) -- they should be 3,9Ohm +/-5%, but my multimeter says that they are 4,6 Ohm. I've connected them to the driver and current is about 250mA (close to 1,25/4,6 = 270mA).
Are resistor wrong labeled or I'm missing something?