This application is a simple-to-use calculator that calculates the resistance of a resistor in a LED circuit.

The simplest circuit to turn on a LED is a voltage source with a resistor and LED in series. The purpose of the resistor in a LED circuit is to limit the current flow through the LED and prevent that it burns. Therefore, it is important to use a suitable resistor for the LED circuit. This application helps the user by picking the ideal resistor for the LED circuit!

LED
A LED (Light Emitting Diode) is a semiconductor light source that emits light when electric current flows through it. A LED contains two important properties: the forward voltage and operating current. The forward voltage defines the voltage drop across the LED, where the operating current is the maximum amount of current that is permitted to go through the LED without damaging the LED. The forward voltage and operating current of a LED differs per type and color.

Resistor
A resistor is a component that is used in electrical circuits to limit the current flow. The resistance of a resistor is measured in Ohms (Ω).

Manual
The application contains a very intuitive design. The user has to go through the following steps to determine the resistance of the resistor in a LED circuit.

1. LED
The user must define the forward voltage and the operating current of the LED. The application includes a list of predefined LED types with the corresponding forward voltage and operating current. However, if the list does not contain the type of LED the user is working with, the user can also enter these properties manually.

2. Power Source
The user must specify the source voltage of the power source in the LED circuit. The application includes a list of predefined power source types with the corresponding source voltage. However, if the list does not contain the type of power source the user is working with, the user can enter the source voltage manually.

3. Circuit
In a LED circuit, multiple LEDs can be connected in series. Also, multiple serial LEDs can be connected in parallel. The user must indicate the number of LEDs in series and the number of serial LEDs in parallel.

4. Resistor
In the final step, the resistance of the resistor is being calculated automatically. In practice, only certain resistor values are available on the market, which are values from the E series. The application recommends a resistor based on a value from the E series and also shows the corresponding color code on the resistor. This color code identifies the resistance of the resistor based on the colors on the resistor. These colors are marked with rings on the resistor and the application supports resistors with either 4 or 5 rings.