How LED Flashlights Are Designed And Manufactured

Atlanta, Georgia-based FOURSEVENS has been on the bleeding edge of the LED flashlight revolution for the last decade. We talked to CEO David Chow about what makes his lights so bright and where flashlight technology is going.http://indefinitelywild.gizmodo.com/win-six-fourse...

FOURSEVENS is one of our favorite flashlight makers, producing the kind of lights that live up to their relatively high price points. Holding and using one feels similar to the user experience offered by that of a quality knife or gun and their light outputs are simply shocking. They're also a favorite of communities like Candle Power Forums. If, after reading this article, you want to learn more about lights like these, we'd suggest you start there.http://indefinitelywild.gizmodo.com/how-to-find-th...

IndefinitelyWild: How'd you get into the LED light business?

David Chow: Early 2000 was when there was what I would call a, "Power LED Revolution." Since the inception of LEDs making 100ma or more, efficiency and performance have made progress in leaps and bounds even exceeding Moore's Law — an advance of two times the performance and efficiency every 18 months.

That is when I first began modifying existing flashlights (typically incandescents) as a service to people who appreciated the technology. As the demand grew, I partnered up with overseas manufacturers to put these high tech illumination devices into consumer hands.

We also saw an opportunity to make flashlights that fit a unique hole in the market; energy-efficient drivers, space-efficient aerospace-grade aluminum alloy bodies, and unique and versatile circuits that are still unmatched in the market today.

How LED Flashlights Are Designed And Manufactured

This page from a FOURSEVENS brochure gives you some insight into the effort that goes into one of their lights.

IW: Why is there a need for a quality light when cheap LED lights also offer incredible brightness, long lifespans and good run times?

DC: I believe that innovating and being the market leader is the way to progress. There will always be cheaper and sometimes even knock-off products chasing after you. We believe in non-compromised product design. If we can make something better, we will, even if it costs more. There will always be cheaper products, but we look forward, not back.

And, FOURSEVENS does not inflate its performance numbers like so many other manufacturers. We under promise and over deliver; we like to surprise and delight our customers. Quite frequently, we'll have people bring their flashlight by our booth at a tradeshow boasting 1000+ Lumens. They'll turn our 500 Lumen flashlight on and compare the beams side-by-side. Usually, that "1000+ Lumens" light then disappears sheepishly back into their pocket.

Many of our lights have a moonlight mode that we claim 30+ day runtimes for. In independent lab testing, they've been shown to run continuously for 57 days [on a single set of batteries — Ed.].

There are so many factors that go into a light; it's not just the LED. The driver circuit, mechanical design, ergonomics, the user-interface; they all have a little story. Every detail has to be considered. Quality isn't what marketing folks tell you, it's in the engineered details of the product, often discovered and appreciated by the user throughout the lifetime of the product.

Take headlamps for example. Customers have been asking us to make one for years, but just look at the walls of headlamps in retail stores — what makes one better than another? Well, we finally came out with one — The Atom AL with 360 Headlamp kit. There is nothing like it on the market.

How LED Flashlights Are Designed And Manufactured

Some of the components that go into a single FOURSEVENS light.

IW: Over the last decade, we've seen huge advances in light outputs and battery run times. Where is the LED light market headed now?

DC: The future can only be brighter. More lumens per watt, cheaper lumens per dollar. LEDs are also going to make it into every sector of the lighting market, just as silicon has made it into every aspect of our lives. Did you know an LED is also made from silicon?

Half of every day is dark. Light is essential for life. The advancement in LED technology will simply enhance every aspect of our lives. Expect LEDs to be everywhere — in our TVs, cars, phones etc. In the Power LED segment — what's exciting to me — expect brighter and longer running portable illumination devices. http://indefinitelywild.gizmodo.com/samsung-galaxy...

IW: Who is Cree and why do they make all our LEDs?

DC: Cree is a wonderful American company in North Carolina. They were very much part of the LED revolution, very much a part of the history books. At one point, they supplied one-third of all the LED dies for the entire planet. In the last few decades they have expanded into LED packaging and now more recently into LED light bulbs for your home or office. They have a rich history and a vast amount of knowledge and experience with LEDs. I've visited their campus and they have several dozen buildings, most of which are top secret. We use Cree exclusively because they are leaders in technology and in the market. http://indefinitelywild.gizmodo.com/fix-absolutely...

IW: How do you make a light biased towards throw or flood?

DC: "Throw" and "Flood" are terms that apply to the optical part of the flashlight and are not related to the LED used. A reflector or an optic are used to consummate (focus) the light coming from the LED. Without that, the LED is just a point source — similar to a light bulb without a lampshade.

I generally prefer a reflector to an optic because they can give a perfect balance of spot and flood. Enough spot to project light out to a distance, but enough flood that you don't get tunnel vision.

So, why do other manufacturers use plastic optics? While it is true that optics may project light further than a reflector, to me it's an inferior arrangement because you end up with almost no flood light. It's like looking through a paper towel core — you only see a spot of light and end up needing to "aim" your flashlight and lose any peripheral vision.

But, optics are cheap and easy. That's because plastic is cheap; super cheap. Reflectors are very difficult to do right. They take real engineering and manufacturing capability and lots of trial and error. It's really an art.

Our reflectors are precision machined from aluminum, then polished and then silver PVD coated and coated again with a clear, optical grade coating to protect the reflective surface (never touch a reflector, it'll ruin it!). Oh yeah, and then we finish it off with an impact resistant glass lens that is anti-reflective coated on both sides — similar to expensive eye glasses. Like I said, we don't take short cuts.

How LED Flashlights Are Designed And Manufactured

A cutaway looking inside one of FOURSEVENS' Maelstrom range of lights.

IW: What are the components that go into an LED flashlight and how do they influence its performance?

DC: Flashlights are fairly simple devices. Basically, it's a light source, a casing to hold the battery, an LED and optical system, and a switch. LED lights differ from incandescents in that they need a driver — you can't just connect the battery directly to the LED. The power to the LED needs to be regulated or they'll go poof. Unfortunately, even some of the major flashlight makers don't use proper drivers; expect those to live a relatively short life.

What also makes us unique is that all our drivers use a computer chip. The interface is pre-programmed to have various different light levels and special modes like strobe, SOS or beacon. Some of our lights can even be user-programmed and some even have the ability to actively manage the thermal temperature. That's more and more important as the drive levels of flashlights go up. Not only will an over-heated LED reduce its lifespan, but it could be a burn hazard to the user. Many of our flashlights (especially the high power ones) will throttle the power to the LED based on the temperature and the run time. These lights are truly "intelligent."

How LED Flashlights Are Designed And Manufactured

David, at his desk.

IW: How can consumers tell the difference between a good light and a bad one?

DC: There really isn't a "bad" flashlight, but finding the best will take some research. Just because a company has been churning out flashlights for decades does not necessarily mean they know what they're doing.

Pay attention to the warranty. Are they claiming "lifetime warranty" just to say it? A lot of Chinese brands are simply playing the me too game — claiming light outputs they don't produce. Some will claim a lifetime warranty, but the whole company will disappear a year or to later, only to resurface later with another brand. Stick with American companies who have support staff that you can call and who speak English. http://indefinitelywild.gizmodo.com/how-to-turn-yo...

IW: Are current battery technologies an obstacle or opportunity?

DC: Battery tech has always crawled along. It will improve over time, but no need to hold your breath. What is more exciting is LED technology and the driver technology that we're constantly developing.

IW: What light do you carry?

DC: I carry the Preon P2. It's just so easy to carry, like a pen.

IndefinitelyWild is a new publication about adventure travel in the outdoors, the vehicles and gear that get us there and the people we meet along the way. Follow us on Facebook, Twitter and Instagram.