LEDs are typically considered direct current (DC) devices because they operate on only a few volts of direct current. This is a good idea for low-power applications, such as a few LEDs or mobile phones, where a DC battery provides the necessary power to run the device. However, other applications, such as a linear strip-lighting system that wraps around the outside of a building for 100 meters, necessitate the use of different considerations. DC drives lose power over long distances, so they need higher voltages at the start of the drive cycle, and more regulators will use more energy.

On the other hand, AC will perform better over a longer distance, which is why people adopt this approach for delivering electricity to homes and businesses worldwide. When we operate devices on alternating current, it is relatively simple to use transformers to measure the voltage from the kilovolts used in power lines to 240 V or 120 V AC. However, this is a complicated method when we use direct current.

If you want to run an LED-based fixture from a mains supply (e.g., 120 V AC), you'll need electronics between the supply and the devices themselves to provide a DC voltage (e.g., 12 V DC) that can drive several LEDs at the same time.

AC-LEDs' development is a new technology that can operate directly from an alternating current power supply. According to Bob Kottrisch of Lynk Labs, one of the companies leading this approach states that alternating current has several advantages. According to him, "with alternating current, power is transmitted and utilized much more effectively.". In this case, you can connect LEDs directly to the end of a cable without needing complicated electronics that convert alternating current back to direct current. This means that you've handled the power more efficiently in the distribution environment, and you've delivered it more effectively without the need for electronics in between.

In addition, Lynk Labs claims that its AC-LED approach can make you lighter and enable you to use less power, which means you'll save your money in the future.

Is it possible to power LEDs with an alternating current supply?

There are many ways to use an alternating current power supply to run LEDs. Some LED lights that aren't connected to a power source need a transformer between the wall socket and the light to get the correct DC voltage. Many companies have made LED light bulbs that we can screw into standard sockets. But they all have small circuits that convert alternating current to direct current before giving it to the LEDs.

If you don't want to use a DC bridge circuit, you can make the LEDs or dies themselves into one. We can give power to LED bridge circuits through alternating current, but they are still operating on direct current, which means that it needs more power to drive them than a "true" alternating current-LED design.

An example of an accurate AC-LED system is the "Christmas tree light" method. In this case, the devices work when connected to an alternating current source. In this case, LEDs are connected in series so that the voltage drop across the whole string is the same as the voltage that came in.

Even though people have tried to make "true" AC-LEDs at the assembly or packaged device level, this hasn't worked out. This is where Lynk Labs, Seoul Semiconductor, and III-N Technology are at the top of the list of companies making progress.

The Christmas tree method is used at the die level in the technology made by Seoul Semiconductor and III-N Technology, which was made by itself. An alternating current gives power to the AC LED device. It has two strings of LEDs that are connected in opposite directions. One string of LEDs is lit up when the AC cycle is positive, and the other string is lit up when the AC cycle is negative. Because of the 50/60Hz frequency of the alternating current mains power source, the strings are energized and de-energized at that time. This makes the LED appear to be always on. Seoul and III-N came up with a way to make LED devices that work on high-voltage 50/60 Hz mains alternating current power sources that use less energy.

What is the role of Lynk Labs technology?

However, Lynk Labs has come up with and patented an AC-LED technology that works with both high- and low-voltage alternating current. This technology is called AC-LED. In this case, Lynk works with existing LEDs or dies and various patented driver designs based on the AC-LED product to make new lights. There are many different types of LEDs, and the company says that it has a complete patent portfolio for them and other things. Furthermore, both Lynk and Philips have substantial intellectual property (IP) in driving LEDs with high-frequency inverter-type drives.

Lynk Labs has taken a very different approach than Seoul or III-N. They have been working on AC-LED technology that can put as few as two die or LEDs in a single assembly or package and driver technology unique to the AC-LED they are working on.

The CEO of Lynk Labs, Mike Miskin, says that "LED lighting products are more important to manufacturers than becoming experts in electronics or semiconductor technologies." The author says that manufacturers of LED lights are more interested in selling their products than in becoming experts in electronics or semiconductors. There is a "plug-and-play" approach that Lynk has used for its customers.

The AC-LED technology developed by Lynk Labs is used on both ends of the system. The drivers developed by the company are intended to provide constant voltage to the AC-LEDs or to provide both constant voltage and constant frequency to the AC-LEDs. AC-LED devices and assemblies are designed to connect to the driver without the need for additional engineering, except a fixture provided by the luminaire manufacturer or the end-user, which may be required.

Many different designs for the AC-LED device or assembly are out there. All of them are based on AC-LED drivers that can provide either a constant voltage or both a constant voltage and a constant frequency, depending on the application.

LEDs are connected in opposite-parallel circuits and run at different frequencies by constant-voltage alternating current drivers from Lynk Labs, depending on the application's needs. The high-frequency/low-voltage driver is used to drive an LED device or assembly that meets the constant voltage driver's specifications. Another option is to use devices and assemblies that can connect directly to mains power or low-voltage transformers, like those used in landscape lighting, instead of using a converter to get the power.

How capacitive current control LEDs?

As long as you use constant-voltage or constant-frequency drivers, the driver drives a C3LED (capacitive current control LED), which is capacitively linked to and operated by the driver. When the capacitor doesn't need any resistive parts in the system, it helps cut down on heat and makes the whole thing run more smoothly.

In this case, the C3LED device or assembly is made up of two LEDs that are on opposite sides of each other. They are connected by a built-in or onboard matching capacitor.

With the C3LED approach, you can get more brightness with less power by using the same LED die in a DC-driven resistor-based circuit. This is because the C3LED approach can give you more brightness with less power, depending on the design of the device or system (in some cases, or both).

When a standard LED device is used, it is usually powered by a DC power source. In its most basic form, this power source has a resistor to keep the voltage drop across the emitter at the right level. When Lynk Lab's C3LED method is used, there are even some LEDs or die in a circuit with a capacitor connected to an alternating current source. The system is set up to use both half cycles of the alternating recent wave to their full potential.

There are usually two or more LEDs on each die of a C3LED device, and each die also has a capacitor. There are two ways to ensure that both halves of the AC cycle are used more effectively.

 Mike Miskin explains in great detail how the capacitor works and why it is essential. "Similar to the resistor in the DC circuit, the capacitor, in this case, drops and delivers the voltage and current to the LEDs in response to the voltage and frequency that the alternating current source sends to the capacitor. This is how it works: (AC source). Capacitors are used when an alternating current source, such as mains power or one of our patented, higher-frequency inverter drivers (Lynk Labs' BriteDriver technology), provides a consistent voltage and frequency. The capacitor not only gives the LEDs a constant current, but it also protects them from other LEDs and the driver if the driver goes out."

The two devices above need different voltages and currents, but they can both be connected to the same AC-LED driver or power source without the need for any extra electronics or parts.

This C3LED method also improves thermal management and energy efficiency because it doesn't need a resistive component in the DC circuit.

Conclusion

We concluded that while led lights are classified as direct current (DC) lights, they can also operate on alternating current. When alternating current sources are used, special circuits (basically driver circuits) must convert the alternating current to direct current (DC). Light-emitting diodes (LEDs) are used in LED lights. They have electrical characteristics similar to those of a P-N junction diode.

References

Considerations for converting a LED bulb from AC to DC power. (n.d.). Electrical Engineering Stack Exchange. https://electronics.stackexchange.com/questions/505050/considerations-for-converting-a-led-bulb-from-ac-to-dc-power

Running LEDs from an AC supply. (n.d.). LEDs Magazine. https://www.ledsmagazine.com/leds-ssl-design/thermal/article/16699720/running-leds-from-an-ac-supply