# Question: What happens if you dont use a resistor with an LED?

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When hooking up an LED, you are always supposed to use a current-limiting resistor to protect the LED from the full voltage. If you hook the LED up directly to the 5 volts without a resistor, the LED will be over-driven, it will be very bright for a while, and then it will burn out.

## Do you always need a resistor with an LED?

An LED (Light Emitting Diode) emits light when an electric current passes through it. The simplest circuit to power an LED is a voltage source with a resistor and an LED in series. Such a resistor is often called a ballast resistor. If the voltage source is equal to the voltage drop of the LED, no resistor is required.

## What would happen if we did not use a resistor?

If there really were no resistance in the circuit, the electrons would go around the circuit, and arrive back at the beginning of the circuit with as much energy as the potential difference (the voltage). That final energy is usually what is dissipated as heat or other types of energy by the circuit.

## Why do you need a resistor in series with an LED?

The slightest difference in LED or supply voltage may cause the LED to light very dim, very bright, or even destroy. A series resistor will ensure that slight differences in voltage have only a minor effect on the LEDs current, provided that the voltage drop across the resistor is large enough.

## Do LEDs act as resistors?

LEDs do not have a linear relationship between current and voltage so they cannot be modeled as simply as a resistor using Ohms Law, V = IR . An LED can be approximated as a resistor with a fixed voltage source.

If you dont, you shouldnt need load resistors. If you do, your vehicle will require load resistors to be wired inline of the LEDs to simulate a properly functioning halogen bulbs resistance.

## What will happen if you do not include a resistor in a simple LED circuit?

It is acceptable to use a LED without a resistor, but some method of limiting the current must be used in order to prevent the device from being destroyed. Failure to limit the current could lead to the device burning out, failing prematurely or even exploding.

## What resistor should I use 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 resistors do I need for LEDs?

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.

## Do I need a decoder for LED headlights?

While you install led headlights into your car and meet the problems like the situation below, you may need a decoder. (1) While you turn on the light after installation, the bulb keep flashing. (2) Computer shows error of headlights. (3) The bulb still keep lighting for a while although you have turned off the light.

## What resistor do I need for 12V LED?

Well use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/. 010=860 ohms.

## What resistor should I use with my 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.