They're still selling incandescent flashlights?

-October 02, 2017

I recently went looking for a basic flashlight to replace one that had rusted out; no big deal. What I needed was nothing special, just a small one which used two or three AA or AAA batteries and was lightweight so it would be easy to carry. This would be simple: go to a store that had a wide selection of sizes and form factor, do some browsing, and make a selection. I assumed that all flashlights would now be LED units, not incandescent.

That trip was a revelation. Roughly one-third of the lights were LED, one-third were halogen (a special type of incandescent), and one-third were incandescent. I thought that the well-known, much-greater efficiency of LEDs, plus the fact that flashlights are inherently power limited by their battery capacity, would have overwhelmed the non-LED types by now.

So I started thinking, why do they still have non-LED flashlights? It might be that the vendors of these non-LED units have very low-cost production which is fully amortized, given the many years they have been making them. Or perhaps the cost differential between the LED and non-LED units at a given brightness level is still substantial for other reasons that I can't see. Perhaps some customers prefer the warmth of the incandescent glow.

From my perspective, the traditional incandescent bulb was reliable but they do eventually burn out (though some flashlights have a spare-bulb holder built into their base). They also survive shock and vibration amazingly well, but I have had problems with corrosion at the overall bulb into socket pairing which, in theory, would not have happened in an LED unit where the connection is soldered.

As an engineer, I did the obvious thing when looking at this array of flashlights: I tried to find and compare otherwise equivalent units with different light sources, but I found there weren’t "apples to apples" match-ups. For example, I hoped to find an LED unit and an incandescent unit with the same output, to see the difference in price and run time, but such an obvious match wasn’t there.

However, I did notice that many of the flashlight packages did have some ANSI specifications and brief definitions of each on the back of the package – in this case, identified as ANSI FL 1 (2009) – which did allow for fair comparison. Three parameters were called out: lumens, run time with batteries provided, and useful distance. Of course, this led me to the engineer's next question: under what specific test conditions are these standards defined?

An online search quickly brought answers, via a clear and useful exposition: "Understanding the ANSI FL1" from PLATO, the Portable Lights American Trade Organization (another group that's new to me) and the excellent PowerPoint presentation "Streamlight: ANSI/NEMA FL1 Standard." The first one summarized ANSI FL 1 (co-authored by NEMA) is very useful and shows a path for comparison of different flashlights, and helped me make a decision; the second and longer one explained in plain terms with diagrams how the various tests are set up and provides more definitions (see image below). Summaries from other sources were also available online, of course.

Even the humble flashlight now has a well-defined standard for measurement of key parameters, such as peak beam intensity and beam distance, as the explanation of the ANSI/NEMA FL1 Standard shows and explains.

I still don’t know why they are selling incandescent/non-LED flashlights, but at least I have learned about the ANSI/NEMA standard for these essential and often taken-for-granted consumer devices. So I'll call that win on my personal list of worthwhile but unexpected learning experiences that I obtained without having to go on a painful path to get there.

What's your view on why there are still non-LED flashlights? Can you recall situations where you inadvertently learned something useful looking while for the answer to a different question?

Bill Schweber is an EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features.

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