# How to wire up this LED?

Hello there,

I've bought this cluster of red LED's from Maplins and I'm unsure how I should go about making a circuit that lights them up using a 9 volt battery. (I also have a simple switch).

The forward voltage of the LED is 2.5v and the forward current is 30mA. According to my calculations I would need to put a 1/2W or greater 220 ohm resistor in the circuit. Is this correct?Also how do I go about wiring the cluster up as they are in fact 6 individual led's. Do I need a resistor for each?

My knowledge of electric circuits is limited.

Many thanks,

Julian

I've bought this cluster of red LED's from Maplins and I'm unsure how I should go about making a circuit that lights them up using a 9 volt battery. (I also have a simple switch).

The forward voltage of the LED is 2.5v and the forward current is 30mA. According to my calculations I would need to put a 1/2W or greater 220 ohm resistor in the circuit. Is this correct?Also how do I go about wiring the cluster up as they are in fact 6 individual led's. Do I need a resistor for each?

My knowledge of electric circuits is limited.

Many thanks,

Julian

active| newest | oldestto your 9 volts.

3 × 2.5 = 7.5 volts

A resistor needs to drop 1.5 V / .030 A ==> 50 ohms.

A

Many thanks,

Julian

I hope you mark the

best answer:)1) Do not use 9v batteries. They are expensive and their total energy storage is crap. Get a AA or AAA battery holder - it will pay for itself after one or two replacements. Preferably use rechargable AA's.

4xAA = 6V

6xAA = 9V

2) Use a series/parallel resistor calculator to figure out what circuit to make. http://led.linear1.org/led.wiz

9volts, 6 leds, 30mA, 2.5V each

leaves 2 strands of 3 leds in series with a 56 ohm resistor on each strand (also in series). The 2 strands are then connected to the power source in parallel.

Many thanks,

Julian