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# Which resistor is used in LED bulb?

## Which resistor is used in LED bulb?

Resistors in Light Emitting Diode (LED) Circuits Such a resistor is often called a ballast resistor. The ballast resistor is used to limit the current through the LED and to prevent excess current that can burn out the LED. If the voltage source is equal to the voltage drop of the LED, no resistor is required.

How much resistance do LED lights have?

You usually find the bulk resistance for LEDs in the range 10 to 50 ohms or so. When running LEDs from 12v or 9v, you can ignore the bulk resistance because it is at most 1/10th of the resistance you would have to add to the circuit to properly limit the current flowing through the LED.

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 Ohm’s Law, V = IR . An LED can be approximated as a resistor with a fixed voltage source.

### What voltage does a LED use?

Typically, the forward voltage of an LED is between 1.8 and 3.3 volts. It varies by the color of the LED. A red LED typically drops around 1.7 to 2.0 volts, but since both voltage drop and light frequency increase with band gap, a blue LED may drop around 3 to 3.3 volts.

How to calculate what resistor a led requires?

For protecting the LED from high current we are using Resistors in series.

• Ohm’s law states that,V = IR
• The required value for the resistor can be obtained by the equation. R= (Vs – Vled )/I
• Source voltage,voltage drop,current,and color of LEDs determine the value of the resistor.
• What kind of resistor do I need for led?

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. The ballast resistor is used to limit the current through the LED and to prevent that it burns.

#### What do resistors do I need for led’s?

You should at least have a 1ohm resistor.. it’s the current that matters, not the voltage. LED only uses as much voltage as it wants.. but increase or decrease the current, and it gets brighter or dimmer. it depends on the power supply, if it is 3 volts and the led is so, then no bui if the power supply’s voltage is higher, then yes.

Why is it necessary to use a resistor in series with a 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 LED ‘s current, provided that the voltage drop across the resistor is large enough.