# What ohm resistor do I need for LED?

## What ohm resistor do I need for LED?

LEDs typically require 10 to 20mA, the datasheet for the LED will detail this along with the forward voltage drop. For example an ultra bright blue LED with a 9V battery has a forward voltage of 3.2V and typical current of 20mA. So the resistor needs to be 290 ohms or as close as is available.

How many ohms is a turn signal bulb?

“The turn signal bulbs are rated at 12 volt, 21 watts. This means they should each present a load to the turn signal relay of about 1.75 Ohms, at 21 Watts.

Does a 12v LED need a resistor?

LEDs can be ran off multiple voltages, but a series resistor is required to limit the current in the circuit. Too much current in an LED will destroy the device. As with all diodes, LED’s will only allow current to flow in the direction from the anode to the cathode.

### How does a load resistor work on a turn signal light?

To add a load resistor to an indicator (turn signal) it has to be wired into each LED light bulb in parallel. I.e. The load resistor goes across the light bulb connections, between the supply and ground.

What kind of resistor do I need for LED light?

Not only is this ugly, but you may also attract the police who think your bulb is burned out. This sounds completely unnecessary and a huge hassle to boot. You will need 50W 6 OHM load resistors and tap the load resistor to the stock harness in parallel.

How big is a load resistor for a 21 watt light bulb?

A typical load resistor for a 21 watt turn signal light bulb would have a rating of 50 watts, 6 ohms. Though please check with your supplier. To someone familiar with electronics, calculating the size of a load resistor may be easy. But to anyone else, it could be a bit confusing…

#### What is the wattage of a load resistor?

The wattage of the load resistor is the value used in the calculation above… The filament light bulb (watts) – The LED light bulb (watts). This will give you the lowest wattage figure, but the load resistor will get very hot (just like a filament light bulb).