The online LED Resistor Calculator determines the resistor to use in various electronic circuits including LEDs. Fill in the blanks of the calculator with the supply voltage and current via the LED to quickly and conveniently check power consumption in a single LED, all LEDs, and the resistor.
A small electronic gadget is known as an LED (Light Emitting Diode). An LED emits light in various colours such as red, green, and blue when current travels through it. If a large number of current travels through the diode, the LED will be damaged. As a result, we add a resistor to the circuit to limit the current flow via the diode.
The number of LEDs in a circuit might vary. Those LEDs will be connected in a series or parallel format.
For LEDs in series, the formulas for calculating resistance and power dissipated are as follows
Resistance R = (V - n * Vₒ) / Iₒ
Power dissipated in a single LED Pₒ = Vₒ * Iₒ
Power dissipated in all LEDs (total) P = n * Vₒ * Iₒ
The power dissipated in the resistor Pr = (Iₒ)² * R
Here are the formulas for calculating the resistance and power dissipated by LEDs connected in parallel.
Resistance R = (V - Vₒ) / (n * Iₒ)
Power dissipated in a single LED Pₒ = Vₒ * Iₒ
Power dissipated in all LEDs (total) P = n * Vₒ * Iₒ
he power dissipated in the resistor Pr = (n * Iₒ)² * R
For more concepts check out physicscalculatorpro.com to get quick answers by using this free tool.
The instructions below will show you how to simply calculate the power dissipation of LEDs and resistors. Follow these guidelines and you'll have the result in a matter of seconds.
The following is the procedure how to use the LED Resistor Calculator
Question 1: If you have one LED and wish to power it with a supply voltage of Vs = 4.8V, what current limiting resistor value should you use?
Solution:
To calculate the current limiting resistor, search for the LED's specified forward voltage and forward current specifications in the datasheet (always RTFM first!). In this case, the voltage and current are 4.1V and 40mA, respectively.
Remember to convert all of your measurements to Volts, Amps, or Ohms! For example, 1mA = 0.001 Amps
When you plug the numbers into the equation above, you get R = 4.8V - 4.1V/ 0.04A = 17.5 Ohms
R = 17.5 Ohms
1. Is a resistor required for each LED?
When an electric current passes through a light-emitting diode (LED), light is emitted. If the voltage drop of the LED equals the voltage source in an electric circuit, no resistor is required.
2. How do you figure out how many resistors you'll need for an LED?
Resistor = (Battery Voltage - LED Voltage)/desired LED current is the formula for calculating the resistor. Find the resistor needed for an LED using the formula.
3. Is it possible to connect an LED without a resistor?
Almost never connect an LED to a circuit without a resistor. When connecting an LED, a current-limiting resistor should always be used to prevent the LED from the full voltage.
4. Will LEDs be brighter at a higher voltage?
Lowering or raising the voltage affects the brightness, but only because it also affects the current: a greater voltage indicates a higher current in an LED.