LED drivers provide power to LED light bulbs and LED fixtures that run on low voltage direct current (DC). While fluorescent lamps are powered by ballasts, LED bulbs operate on a lower voltage and need LED power supplies to convert alternating current into direct current and to keep the power flowing throughout the whole circuit. LED drivers are connected to the main power source and increase or decrease the input voltage depending on the required level and then feed it to the fixture.
Contrary to LED bulbs that have an integrated or internal driver, commercial and large-scale LED fixtures use an external LED driver. The advantage of external drivers is it allows for easier replacement when the driver fails or goes bad over time. It is more cost-efficient to replace the power supply rather than the whole fixture, and there is a variety of replacement LED drivers to choose from. LED drivers are dimmable and IP rated for outdoor damp or wet locations.
Constant Current LED Drivers
Constant current LED drivers work with a fixed output current and produce varying wattages and output voltages. Constant current drivers send a specific output current in milliamps or amps to the fixture. The wattage value is directly proportional to the output voltage received, so a higher voltage sent results in a higher power consumption and stronger lumen output. LED drivers typically produce currents within 350mA to 6000mA. Constant current drivers are most commonly used in outdoor fixtures, architectural lighting, general indoor fixtures and sign lighting.
Constant Voltage LED Drivers
Constant voltage LED drivers convert standard 120-277V AC to produce a steady stream of output voltage in either 12V or 24V direct current (DC). The fixed voltage allows constant voltage drivers to produce a range of output currents and wattages up to a maximum. Since direct current typically loses power as it runs through a circuit, 24V configurations are ideal for longer runs to minimize the voltage drop. Constant voltage LED drivers are normally used for landscape fixtures, channel lighting and under cabinet lighting.
LED Dimmable Power Supplies
LED power supplies and drivers use 120-277V AC input voltage and convert it to lower 12V or 24V DC output voltage for compatible fixtures. Power supplies can be hardwired into the power source or plug-in with a cord and plug. The two types of hardwired LED power supplies are dimmable magnetic power supplies and electronic power supplies. Most LED dimmable power supplies are Class II rated and have a dimmable feature.
LED Low Voltage Landscape Transformers
LED transformers used for landscape lighting are especially rated IP65 or greater for both indoor and outdoor damp location and wet location use. LED landscape lighting transformers are made of non-corrosive material like bronze or stainless steel that can withstand water, dust and extreme weather. LED low voltage landscape power supplies convert line voltage 120-277V AC current into low voltage 12V DC current that is used by landscape fixtures. One feature of landscape power supplies is the multi-tap option from 12V - 15V that allows the current to be run longer while minimizing the voltage drop.