Kalkulator do obliczania rezystorów do LED, na różne napięcia : strona
http://translate.google.pl/translate?prev=hp&hl=pl&u=http%3A%2F%2Fwww.hebeiltd.com.cn%2F%3Fp%3Dzz.led.resistor.calculator%23single&sl=en&tl=pl
gonzo181