Keep your (lights) cool

The advantages of LED lighting in machine vision are well known: stable output over a long lifetime. But did you realize that LEDs themselves are vulnerable to high temperatures? In fact a single spike over 100 degC in the junction temperature can dramatically shorten the lifetime of an LED lamp.

So what do you do? I suggest designing your system with thermal management in mind. For example:

• Mount LED lights securely to large aluminum rails where they can act as heat sinks.
• Keep the lights away from heat sources such as gas jets or induction heaters.
• Ensure that shrouding around the vision system has sufficient ventilation to maintain airflow.
• Run the lights at less than maximum power. If possible, strobe them to reduce the total duty cycle.
• When shopping for lights, don’t buy the cheapest you can find. Quiz the manufacturer about his design handles high temperatures.

Lighting manufacturers quote some very long lifetimes, but you won’t see these if you let your lights get too hot. Increase the reliability of your system by take a few minutes to consider how you’re going to keep the temperatures down.