How to select the right LED Driver?

We need to convert AC load to DC load to drive LEDS with constant current solutions. While converting from AC to DC there exsit a loss. These losses are varying from drivers’ manufacturers to manufacturers.To obtain efficient LED application, LED driver should be selected with high efficiency and long lifetime. AS most of the design get failed due to bad LED Driver selection.

Choosing the right LED driver is like choosing the right tool for job. First, you need to know what job is!Here are the main questions you should have the answers to before choosing a driver:

•  What type of LEDS are being used and how many?
• What type is needed, constant current or constant voltage?
• What is required voltage range in system?
• What are the size limitations, if any?
• Do you need isolation?
• What are the main design goals?(size, cost, efficiency, performance, indoor or outdoor etc)
• What feature are desired?(dimming, pulsing….)
• What is the budget for driver?

 Once these questions have been answered, choosing the correct driver is a matter is finding what is currently available and determining if it is suitable for your application.

 Key Points For Drivers Selection

1, Efficiency

Driver efficiency can range from 75% to 94$ for switch-mode power supplies depending on the design and manufacturer. Losses are typically due to switching, internal resistance, and transformers selection. Efficiency for LED drivers should be greater than 85%.

2, Power Factor(PF)

Power factory is a measure of how efficiently electrical power is consumed. In the ideal world power factory would be 1. Unfornately in the real world power factor is reduced by highly inductive loads to 0.7 or less.

The introduction of power factory correction capacitors is a widely recognized method of reducing an electrical load, thus minimizing wasted energy and hence improving the efficiency of a plant and reducing the electricity bill.

It is no usually necessary to reach 1, the power factor. Since most supply companines are happy with a PF of greater than 0.9

 3 ,Reliability

The expected life of the driver should match that of the LED over the rqured operating temperature range of the lighting system. Vibration, heat, moisture, and over environment conditionsc can have negative effects on components that comprise the LED driver.

4, Total Harmonic Distortion(THD)

The total harmonic distortion, or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency. THD is used to characterize the power quality of electric power systems. In power systems, lower THD means reduction in peak currents, THD value is recommended to be less than 20%.