Powering LEDs

Having the right power supply is important in ensuring that you get the best performance from LEDs. There are numerous factors to consider when picking a power supply. Whether is for a new fitting or retrofitting existing fixtures, you will have to ensure that the power supply perfectly suits the fixture. These factors include;

Constant voltage or Constant supply
Wattage
Voltage/Current
Dimmability

Constant voltage vs Constant current supplies

Constant voltage supplies

Constant voltage power supplies can be used where the LEDs have Resistors or have been primarily designed to use constant-current drivers as they have constant current drives within the system already. Resistors and constant current drivers call for a constant DC voltage thus is you have AC sources then you will need a power supply that will convert the AC to DC hence the need for constant voltage power supplies.

Constant current power supply

Constant current drivers are used to control the amount of current supplied to the LEDs to avoid fluctuation of brightness which could, in turn, shorten the lifespan of the LED. Constant current power supplies are used for fixtures that demand stable output current and operate within a range of voltages. Before purchasing a constant current driver, it is important to verify the output current and voltage of the driver and ensure that it is compatible with LEDs current and voltage rating.

Wattage

Before buying a constant voltage power supply, determine the number of watts you LED consumes. In case the lights are many, sum the watts consumed to arrive at the total number of watts required. When you have established the number of watts required, add 20% of the same so that you do not overwork the power supply.

Voltage/Current

When replacing or building a constant current LED fixture, ensure that the output current and voltage of the driver is compatible with the LED’s rated current and voltage. If the setup is primarily designed to be driven by a constant current driver, confirm the specification to ascertain its operating requirements and ensure that the power supply you intend to buy matches these requirements. Also, ensure that the power supply input voltage matches the designated source.

Dimmability

For dimmable LEDs, you will have to choose a dimmable driver or power supply. The specs of such power sources will often state whether they are dimmable or not. The specs table also outlines the dimmer control types for the driver or power supply. There commonly used dimmer

TRIAC dimmers
Pulse-Width Modulation Dimmers
Resistive dimmers
1-10 Volt dimmers
0-10 Volt dimmers

Ensure you pick the one that best suits your LED.

Temperature and Weather resistance

It’s important to consider the environment within which the Power supply is going to operate. Ensure that the environmental temperature does not exceed the temperatures specified on the power supply. Every power supply has an ingress protection (IP) rating which indicates the size of solids and pressure of liquids that the power supply housing can resist. Ensure to pick the power supply with the appropriate IP rating.