LED Resistor Calculator Plus 1.1

The LED resistance calculator serves as a valuable tool for determining the appropriate series resistor required for various combinations of light-emitting diodes (LEDs). This calculator enables users to select the correct resistors essential for making safe connections with any number of LEDs.

Each LED has a specific current rating it can handle safely. Exceeding this maximum current can lead to damage. Thus, incorporating a series resistor to limit the current is a standard practice in LED applications.

By utilizing the LED resistance calculator, users can easily ascertain the value of the resistor needed to restrict the current flowing through the LED. After inputting the necessary parameters, the calculator will automatically compute the results, which include the Resistor Value, Resistor Power Dissipation, and Recommended Resistor Wattage.

• Formula: R = (Vs - Vf * Nled) / If

Where:

• Vs - Supply Voltage
• Vf - LED voltage drop, which varies by the color emitted.
• If - LED current, typically ranging from 10-30 milliamps for common 3 mm and 5 mm LEDs.
• Nled - Number of LEDs in series.

An LED is fundamentally a two-lead semiconductor light source. It functions as a p-n junction diode that emits light when activated. When a suitable current flows through the leads, electrons recombine with electron holes within the material, releasing energy as photons—an effect known as electroluminescence. The emitted light's color corresponds to the energy band gap of the semiconductor. Typically compact in size (less than 1 mm²), LEDs often utilize integrated optical components to shape their radiation patterns.

Originating as practical electronic components in 1962, early LEDs produced low-intensity infrared light. Infrared LEDs continue to be widely utilized as transmitting elements in various remote-control applications for consumer electronics. Initially, visible-light LEDs emitted low-intensity red light; however, contemporary advancements have yielded LEDs across visible, ultraviolet, and infrared spectra, exhibiting significantly higher brightness levels.

* Note that this method is not recommended for high-current LEDs, which require a more reliable switching current regulator.