Last Updated on October 23, 2023 by Kevin Chen
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LEDs have revolutionized the lighting industry by a great margin. A good percentage of the lighting technology that we are using today is powered by light-emitting diodes. A diode is an active electronic component that comprises two electrodes; an anode and a cathode. The electric current in the diode flows in one direction only and not the other.
Usually, the direction is from the anode to the cathode. Diodes are made of semiconductor materials such as selenium, gallium, and silicon. A key property of the semiconductor materials is they conduct the electric current when conditions allow. Otherwise, there are cases and incidences when they won’t conduct the current.
There are different types of diodes and one of them is the light-emitting diode. LED lighting is a semiconductor component that utilizes the electrical properties of diodes whereby it uses electric current to emit light. It is different from the photovoltaic cells which use light to generate electric energy.
Working principle of LED lighting
To understand the role of diodes in LED lighting, it will be prudent to know the working mechanism of LED lighting. The whole working principle is based on electroluminescence whereby a material emits light when subjected to electric energy.
Like other diodes, LEDs are made of semiconductor materials that have both p-type and n-type materials. These two are the holes and electrons whereby the holes are positively charged while the electrons are negatively charged. These two materials have distinct electrical properties, especially when connected to electric current. The current will force both the electrons and holes to move toward the junction.
Recombination of the holes and electrons will take place at the junction and the energy will be released in the form of light. The intensity of the light will depend on the electrical energy due to the combination of holes and electrons.
How do LED lighting systems emit different colors of light? Well, it depends on the doping process that has been used. A little tweak here and there will result in different colors of the LED lights. Additional impurities may be added to the semiconductor materials to achieve different color settings.
Probably you would expect that the collision of holes and electrons at the junction will result in heat. The good news is that LED are highly efficient and there is minimal generation of heat. Most of the energy released is converted to light instead of heat.
Functions of diodes in LED lighting
Now that you know what LED lighting is and how it works, let’s look at the main functions of diodes in LED lighting systems.
Illuminate the lamp
This is the primary function of diodes in the LED lighting system. The diode is responsible for illuminating the lamps which end up producing lights. The diodes have n-type and p-type materials which when combined at the junction produce light. The intensity and color of the illumination will depend on the specifications of the diode. This explains why some LED lighting systems are brighter than others, or illuminate in different colors.
AC relay source rectification
Diodes are also used as power rectifiers. This is usually ideal when they are connected to AC power sources whereby they convert the power from alternating current (AC) to direct current (DC).
How do diodes achieve this? This is mainly due to the unidirectional nature of the diodes whereby they allow current to flow in one direction only. We know that the current in the AC circuits keeps fluctuating in both directions. When a diode is introduced to this circuit, it will force current to be transmitted in one direction. This is important in ensuring the illumination’s stability: an essential aspect of lighting systems used in crucial application areas such as healthcare.
High voltage protection
Diodes in LED lighting devices are also used to offer protection against the dangers of high voltage and current. They are able to achieve this task just by the fact that they allow the current to move in one direction. This implies that if you don’t want high voltage to go in a certain direction, you will have to do is include diodes in a circuit.
This functionality of the diode is more applicable in LED lighting circuits that have sensitive components. Diodes will be installed in close proximity to such components to shield them from the effects of high voltage. They are usually installed in a reverse-bias direction, so no current will pass through such components.
The regulation of voltage in the LED circuits is closely related to the protection. This function entails limiting voltage in a particular component to ensure that it does not exceed a specific value.
To achieve this, you first have to know the value of the diode that will be suitable for the LED circuit. If the LED lighting needs lower voltage yet the circuit is supplied with high voltage, you will have to use a diode to cut off the extra voltage. This way, the LED lighting will operate smoothly as expected.
Diodes are used as switches in circuits
In some cases, diodes are included in the LED lighting systems to operate as switches. The main advantage of using them as switches is they automate the process of turning LED lights on and off.
How do diodes operate as a switch?
When the voltage in the circuit exceeds a defined threshold, the internal resistance of the diode will go up and this will force the diode to be reverse-biased. In this state, it will open the circuit hence switching off the LED lighting.
From this guide, it is clear that we cannot ignore the roles of diodes in LED lighting. If you are working on an LED lighting project, you should pay special attention to the specifications of the diodes that you will use for the lighting. It will determine the light output that you will get from the system.
It all starts with choosing reputable diode suppliers in China. They will ensure that you get the right diode that will be suitable for your LED project.
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