need to know voltage for blue/red flashing leds what size resistors I need do I need capacitaor 9v battery

I'm making a red/blue flashing led bike light with a 9v batt what resisitors I need there are eight lights installed in a circle canister Plastic. The lights already flash when connected to a battery, what is the voltage for those kind of 2 ccolored leds. Thanks a LOT GUYS KEEP UP THE GREAT WORK i'M A BIG FAN FOR 1 YEAR NOW YOUR SITE HAS KEPT ME SANE pAUL

sound917 years ago
Here is a website that I have used many times when working with LEDs. Just insert the required fields, and Make sure you check what voltages the different colored LEDs take by clicking the question button on the "diode forward current".

frollard7 years ago
What did the specifications say when you bought the leds? Where did you get them? bright leds are pretty standard at 20mA but there may be a difference since they have a small integrated circuit inside them to make the flashing effect.