How Do You Reduce the Voltage of an LED? Answered! (Step By Step)

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High voltages can damage many devices and components if they are more than the limit of the components; for example, LEDs have a certain limit for the voltage they can tolerate.

If the voltage exceeds this limit, the bulb of the LED is fused off, which damages the LED’s internal electronic structures by the voltage spikes. Therefore, the voltage has to be reduced to suit the needs of the LED.

How Do You Reduce the Voltage of an LED?

To reduce the voltage of an LED, you need to connect a resistor in the same circuit of the LED; the resistor and The led have to be connected in series; therefore, the voltage across the LED will be reduced. You can reduce the voltage across the LED using a resistor and following these steps:

  1. First, apply Ohm’s law (V=IR) to find the required amount of resistance to reach the required voltage.
  2. For example, if you have an LED that requires 2 volts and 20 milliamperes, the power supply provides 12 volts. Therefore, you need a resistor with a drop voltage of 10 volts.
  3. To calculate the resistor’s resistance, divide the voltage by the current of the circuit, 10/0.02 = 500 ohms.
  4. To have a more accurate voltage drop, you should use a 550 ohms resistor; after getting the resistor, connect it to the LED circuit in series.
  5. Don’t connect the LED initially; connect the resistor first and then use a multimeter to check the voltage across the resistor and see if it’s the right amount.
  6. For example, if you wanted the LED to have 2 volts across its terminals and use a 12 voltage supply, the resistor should have ten voltages across its terminal.
  7. If the resistor’s voltage is fine, then connect the LED and test the circuit; the LED should be safe.

Does The Color of LED Determine its Required Voltage?

Yes, the color of the LED determines the voltage of the LED, and the LED brightness is determined by the total resistance connected in series with the LED; for example, most LEDs have their maximum brightness when supplied with 20 milliamperes, if you have an LED of 2.2 volts and supply voltage of 10 volts.

The LED brightness is determined by the total resistance connected in series with the LED; for example, if you have an LED of 2.2 volts and supply voltage of 10 volts, most LEDs have their maximum brightness when supplied with 20 milliamperes.

Therefore, to calculate the resistance of the resistor, you need to calculate the voltage, 10-2.2 = 7.8 volts, then divide the voltage by the current of the LED, 7.8/0.2 = 390 ohms. If you want to decrease the brightness of the LED, you need to connect a variable resistor.

When increasing the resistance, the brightness of the LED will decrease because the current entering the LED will decrease. Still, you have to be careful when using a variable resistor because if the resistance gets lower than 390 ohms, the LED will be brunt, each LED color has its required voltage, for example:

  • Red LED requires 2 volts.
  • Green LED requires 2.1 volts.
  • Blue LED requires 3.6 volts.
  • White LED requires 3.6 volts.
  • Yellow LED requires 2.1 volts.
  • Orange LED requires 2.2 volts.
  • Amber LED requires 2.1 volts.
  • Infrared LED requires 1.7 volts.

How Much Voltage Can LED Tolerate?

Most LEDs usually can tolerate up to 4 volts; meanwhile, blue and white LEDs can only tolerate up to 2 volts. However, the LEDs should be supplied with less than their maximum current to be safer,  usually, the 5-millimeter LEDs require 2o milliamperes current.

Therefore, they should be supplied with 10 to 15 milliamperes current to be on the safe side; the maximum brightness for an LED can be achieved when they are supplied with their maximum current.

What Happens When an LED is Connected To a Voltage Higher than Its Limit?

When the voltage supplied to an LED exceeds the limit of the LED, it damages the LED and can burn it. This is because the LED as a component depends on the circuit’s current, not the voltage, therefore when the voltages change or exceed the limit, the bulb of the LED is fused off.

Resulting in damage to the internal electronic structures of the LED by the voltage spikes. This wears the LED parts and panel, which shortens their life cycle leading to the failing of LED. In addition, when the voltage supplied to the LED is higher than what is required, the temperature of the LED will increase; this puts an overload on the parts of the LED and shortens its life of the LED.

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What Type of Current Does The LED Use?

The LEDs use direct current because they allow the current to pass only in one direction; when an LED is connected to a DC voltage source, many other components should be connected to the circuit to protect the LED. For example, voltage regulators, resistors, and current regulators are used to limit the voltage and the current for the protection of the LED.

What Happens When You Use Lower Voltage for LED?

Lower voltage has no bad effects on LED; however, it affects the LED efficiency because the voltage supplied to the LED is not enough to make it operate at its full power. Interestingly, the lower voltage is safer than the required voltage and has no damaging effects on the LED.

In addition, the lower voltage increases the LED’s longevity and lifetime, the only downside of using a lower voltage is that you be paying for a higher quality LED that can tolerate a larger range of voltage and can have more brightness. LEDs that are designed for lower voltage are cheaper than these high-quality LEDs.

How To Control The Intensity of LED?

1) Step One

Bring a breadboard circuit, and put the red colored and the black colored wires from the battery’s connector on the side rails of the battery to use them later. Next, get a potentiometer and connect its terminal to the board using three different wires, a wire for each terminal. Finally, you can install the LED anywhere you prefer on the board. 

2) Step Two

Bring two resistors, one is 1000 ohms, and the other is 270 ohms, connect one of the ends of the 1000-ohm resistor to the potentiometer’s middle lead and connect the other end to another rail. Next, connect one of the ends of the 270-resistor to the longest lead in the LED and connect the other end to the rail of the 1000-resistor. 

3) Step Three

Connect the battery’s positive terminal to the potentiometer’s left lead, and connect the battery’s negative terminal to the potentiometer’s right lead. Finally, attach the battery’s negative terminal to the LED short lead

4) Step Four

The last step is to connect the battery to the connecter to provide the circuit with power; now, you can use the potentiometer to control the LED intensity; the potentiometer is used to decrease and increase the resistance in the circuit, so the voltage supplied to the LED differs, which results in different intensity. 

Conclusion

To sum up, to reduce the voltage of an LED, you need to connect a resistor in the same circuit of the LED; the resistor and The led have to be connected in series; therefore, the voltage across the LED will be reduced. In addition, the LED’s color determines the LED’s voltage; for example, a red LED requires 2 volts, and green LED requires 2.1 volts.

The LED brightness is determined by the total resistance connected in series with the LED; when the voltage supplied to an LED exceeds the limit of the LED, it damages the LED and can burn it. This is because the LED as a component depends on the circuit’s current, not the voltage.

Therefore, when the voltages change or exceed the limit, the bulb of the LED is fused off, resulting in damage to the internal electronic structures of the LED by the voltage spikes. This wears the LED parts and panel, which shortens their life cycle leading to the failing of LED.

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