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How to Reduce the Amperage From LED

A light-emitting diode -- or "LED" for short -- is a semiconductor device that illuminates when voltage is applied across its leads. Like many other semiconductor devices, LEDs are current-controlled. If too much current passes through an LED, the LED will become damaged and will require replacement. To reduce the amperage going to or coming from an LED, you may choose to install a current-limiting resistor in series with the LED.

Things You'll Need

Electrical pliers
Electrical wire
Red light-emitting diode
200-ohm resistor
3-volt DC power supply

Instructions

- 1
  Use the pliers to cut two pieces of electrical wire, each piece being at least 4 inches long. Strip 1/2 inch of insulation from the ends of each wire. Ensure that the power supply is turned off.
- 2
  Twist together one end of the first wire with the anode lead on the LED. Twist one of the resistor leads to the cathode lead on the LED.
- 3
  Twist together one end of the second wire to the remaining resistor lead. Connect the loose end of the first wire to the positive terminal on the power supply. Connect the loose end of the second wire to the negative terminal on the power supply.
- 4
  Turn on the power supply. The LED will illuminate; however, it will be dimmer than if the LED was wired to the power supply without the resistor connected in-line.

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