Application Guide to LED drivers

Application Guide to LED Drivers
Installation Advice

This white paper will guide you through the process of choosing a suitable LED power supply (LED driver) for your application and explain how to get the best out of you power supply.

There are a number of things you will need to know before you can start to select the most suitable power supply.

Table of Contents

Application Guide to LED drivers. 1

Electrical Specifications of the LED Light Fitting. 2

Constant Voltage LED Drivers. 2

Constant Current LED Drivers. 2

Dimmable LED Drivers. 3

Trailing or leading-edge TRIAC Dimmers. 3

.. 4

1-10V and 0-10V Dimmers. 4

PWM Dimming. 5

Resistance Dimming. 5

DALI Dimmable LED Drivers 6

What Load Can Be Placed on a LED Driver?. 6

What is Dead Travel?. 6

LED Drivers with PWM Output 7

Power Factor Correction. 8

Environmental considerations. 8

IP Ratings. 8

Sunlight and Temperature. 9

De-rating a power supply in higher ambient temperatures. 10

Wiring LEDs to Constant Current LED Drivers. 10

Do Not Connect LEDs to a Constant Current LED Driver in Parallel 10

Electrical Safety and EMC Approvals 11

Information for Original Equipment Manufacturers and Designers. 13

Simple Constant Voltage (CV) 13

Direct Drive Constant Current (CC) 13

Constant Voltage & Constant Current 14

What Topology? Series or Parallel?. 14

Further Information. 15

Electrical Specifications of the LED Light Fitting

Before a LED driver can be selected the electrical specifications of the LED lighting need to be identified.

Depending on the design of the light fitting it will require either a constant voltage LED driver, or a constant current LED driver.

Constant Voltage LED Drivers

Constant voltage LED drivers are used to power LED light fittings, or LED strips that incorporate some form of electronic current regulation.

They maintain a constant voltage output by allowing the output current to vary.

The two most common voltages used are 12V and 24V and are readily available. However, there are light installations that require a higher output voltage. Reputable stockists will usually carry some stocks of the less common voltages.

Apart from the required voltage, you will also need to know how much power (WATTS) are required. If the LED driver is too small, it could become overloaded which has the potential to shorten the life of the LED driver.

Constant Current LED Drivers

Constant current LED drivers maintain a constant current output by allowing the voltage to vary.

This type of LED driver is used to power LED light fittings, or LED strips with no internal current regulation.

The actual current required to drive the LED light fitting can vary anywhere between 250mA, right up to 40A.

Once you have established the current required to power your lights, you will also need to know the forward voltage range required to drive the LEDs. The LED’s electrical specifications should show the required current, which must remain constant and the voltage range in which the current should be delivered in order for the LEDs to work.

You can select a LED driver with a wider forward voltage range than required. It is important that the voltage range of the LED driver accommodates both the minimum and maximum voltage required to driver the lights.

Dimmable LED Drivers

If a dimmable LED driver is required, it is important to ascertain what type of controller will be used to dim the lights. This could be something as straight forward as the trailing, or leading-edge TRIAC dimmer switches you find in most homes, or it could be a DALI based lighting control system.

The most commonly used dimming controllers in Australia include:

Click on the below link to download the complete PDF document:

Application Guide to LED Drivers.pdf

13 November 2018