Newbie needs help with wiring LED

Thanks everyone for the replies. With all the differing options I am getting a little confused so wanted to clarify.

I have decided on 3 x 3V led wired in series.

So I was going to go from the 12V DC adaptor with the live to a resistor (150Ω or 300Ω - maybe lower as each LED is 20ma but advised to go under to 10ma) then from that to first LED live then negative to live of next and so on with last negative going back to power supply.

I was going to get one of these **broken link removed** and a 12v DC this is 1A.

Again sorry for my lack of understanding in this matter but wanted to double check before ordering resistors and power supply.

Thanks

SykesIT said:

I have decided on 3 x 3V led wired in series.

So I was going to go from the 12V DC adaptor with the live to a resistor (150Ω or 300Ω - maybe lower as each LED is 20ma but advised to go under to 10ma)

Click to expand...

NO! If you reduce the resistor value then Ohm's Law says that the current goes higher.

Do you know the polarity of the LED wires?

audioguru said:

NO! If you reduce the resistor value then Ohm's Law says that the current goes higher.

Do you know the polarity of the LED wires?

Click to expand...

Yes I have marked each led negative wire tested with a 3v cell battery as both wires are same.