for 3 LEDs, red blue and green, connected all 3 in parallel at a 9v battery, what resistor should I use? I tried 1K, but no led lights, and then 460 ohms, here just the red and the green function. At the moment I don' t have another resistor, that's why I am asking. Maybe 300, 200 ohms? What should I buy?
Thanks in advance.