Frequently asked questions and answers about LED driverspower supplies

2019-09-28

LED drivers or LED power supplies provide the LED bulbs with the power needed to achieve optimum performance, just like electromagnetic ballasts or low-voltage bulb transformers for fluorescent lamps. Continuous technological innovation and often confusing terminology may make the choice of LED drivers seem numerous, even for experienced professionals. The purpose of this article is to answer some of the most common questions and to help lighting designers/designers solve complex labyrinths that choose LED drivers.

What is an LED driver, why do you need one?

If there are no three basic components, the LED will not work: the light-emitting chipset; the driver that regulates the power of the light source; and the heat sink for the cooling device. LED drivers are an important part of this technology because LEDs use the power converted by the driver to illuminate. These drivers are very efficient at converting power, which is why 100W LED bulbs can replace 400W metal halide bulbs.

What is the difference between a constant voltage driver and a constant current driver?

One of the most important factors to consider is whether the application requires a constant voltage (CV) or a constant current (CC) supply. CV drivers provide a fixed voltage for lighting applications where the number of LED strings and current consumption is unknown. In these applications, current control is done by other components of the LED itself. The CC driver provides a fixed current for applications that require a constant current to be directly connected to the LED. This type of driver operates over a limited voltage range, so drivers with the appropriate voltage rating must be selected. GRE Alpha, a leading designer of solid-state LED power supplies, offers a variety of dual-mode LED drivers to increase the flexibility of lighting design.

What is an AC LED driver?

The function of the AC LED driver is to reduce the input voltage to a lower output voltage to meet the low voltage requirements of the LED, typically 12 or 24 volts. It is important to consider the power requirements because the AC LED driver can only be used with lamps that already have an internal AC to DC converter.

What is PF and PFC, why is it important?

The power factor (PF) is the relationship between active power and apparent power and represents the ratio between the actual load (kW) and the apparent load (kVA). Power factor correction (PFC) is critical for selecting an LED driver because the current load of a lower power factor LED is greater than a load with a higher power factor. Low PF can result in greater power loss in the utility line, so the LED driver must meet the PFC standard.

Does the driver support dimming and no flicker?

If your application requires any unique features (such as dimming), be sure to choose a high quality LED driver with flicker free dimming. Today's wireless LED drivers are designed to be compatible with powerful wireless protocols such as Bluetooth LE, Zigbee, EnOcean, Thread, Z-Wave and KNX for near-instant feedback without interference. Designers must understand the various protocols available and compare their strengths and limitations.

Can I use the driver in an outdoor app?

IP67 rated LED drivers are available for outdoor applications. Products with this rating are fully dust-proof and can withstand up to 1 minute of water for up to 30 minutes.

Is the driver compatible with the wireless control system?

Today, many lighting control systems must be able to connect to the Internet of Things (IoT), which is the name of the linked wireless physical device network. If your system design requires a wireless connection, you must ensure that the LED driver is wireless and can "speak" the same language as the other devices in the system. Connected devices help designers plan for more energy-efficient, more intuitive systems. If your LED driver does not have to "talk" to a loT connection protocol, there are various LED dimming module plug-ins on the market. These products allow designers to add project design choices. Richard Fong, director of meanwell, said: "This is one of the core unique innovations of our modular system approach."

What is potting (packaging), why is it important?

Potting increases the IP (degree of protection) rating of the drive/power supply by providing a waterproof barrier to protect the component from liquid attack. This is especially important for outdoor applications. The potting material also transfers heat from the critical power components to the surface of the housing, reducing thermal stress and increasing component durability.

What are the benefits of using a high power efficiency drive?

Energy efficiency is the main reason customers are eager for solid-state LED lighting control systems. Save energy with efficient drives. More efficient power supplies dissipate less heat, extending product life.

What is the expected life of the LED driver?

In addition to saving energy, LED lighting systems must also stand the test of time. LEDs are known to have a longer life than conventional lighting systems. Therefore, the LED power supply must achieve the same life expectancy as the LED. Mean Time Between Failure (MTBF) is a good indicator of the quality of LED drivers. Leading LED driver manufacturers such as Meanwell have listed MTBF information in their product data sheets. Lighting system designers can rely on the integrity of these components for system control.