By BizLED Bureau
Feb 26, 2016: Selecting the right driver for LED tubes is a critical step to optimize lighting. Crucial factors like efficiency, lumen output and light uniformity have improved while costs have decreased due to mass scale production.
Few years ago, LED tubes were giving 80 lumen per watt in efficacy, and now these tubes deliver more than 120 lumens in few cases. Real efficacy depends on factors such as color rendering index (CRI) and clear versus frosted variables. These multiple choices have often confused the buyer as well.
LEDs are supposed to keep cool and tubes generate heat, making them as unfavourable combination. Another heat generating factor is power supply, which is also known as driver. Drivers in LED tubes are the critical differentiating factor to identify one form from another. We will highlight some of the features of internal and external drivers, below:
Internal LED driver integration
There are four types of LED tubes integrated with internal drivers that are suitable for offices, retail, schools, etc. They are
Parallel Internal driver: The most common internal driver that is mounted in a parallel fashion along the length of LED tube. The heat generated from the LED driver in these LED tubes usually damages the LEDs in some cases. This can lead to degraded color, less efficiency, and less longevity. Other disadvantage in LED tubes with parallel internal driver is, tube fails when the driver fails in an integrated parallel driver. There is no possibility of dimming and light output quality also fails. Hence these LED tubes have become outdated.
Thermal isolation end-cap driver: These drivers are placed at the end cap of the tube and away from the LEDs due to thermal isolation. Such designs are better than parallel-driver tube but the heat generated from the driver remain isolated and entire tubes fails when the fixed integrated driver suffers any failure.
Thermal isolation and replaceable driver: The early end-cap drivers can be replaced easily without even cutting wires for some products. Only driver needs to be changed and not the whole tube with the LEDs.
Ballast-compatible driver: Ballast-compatible drivers, also known as “plug and play”, make the tubes better. Such tubes are required to be clipped into the fluorescent tube connectors, and mechanic or electrician is required for installation. It is one big disadvantage, which is, when the original fluorescent ballast fails, the end user needs to purchase ballast which can only be installed by an electrician. The tube wattage is a little higher because of the pass-through burden on the ballast.
LED lighting guide: How to choose LED tubes with the right driver
External LED driver integration
Major application of LED tubes with external drivers, is in hospitals, parking garages, fire and rescue centers, emergency exit stairs, egress hallways, etc.
External driver with power to pins: The first type of external-driver topology involves wiring the DC power output directly to the main point. Positives are maximum driver thermal advantage. The driver has enough space and manufacturers can add dimming and other smart control benefits. These drivers are easily replaceable. However, LED tubes with external drivers cost more than internal-driver tubes.
External drivers connected directly to tubes: Advantages are maximum driver thermal benefits with optional dimming and other smart controls. Tubes remain unaffected while the driver can be replaced.
Tip: Tube reliability has improved vastly and has gone from one to three years up to five years for many products. Many LED tubes also offer 10-year warranties. We suggest buyers to read the conditions before making any purchase.