The All-Around Performance of LED Flashlights|
Choosing a flashlight has become a great deal more complicated since the days when aluminum bodied flashlights with three D cell batteries dominated the market. Nowadays there are as many types of flashlights as there are possible uses for them, and with advancements in lighting technology continually growing, the variety increases. Despite this there are actually only three main types of lamps that are practical for use in flashlights, and these make up the majority of bulbs used in most flashlights on the market today.
The first and still most common type of lamp used in flashlights is the standard incandescent bulb. Whether it is a plain incandescent, Krypton, or Halogen bulb, it still consists of a simple wire filament stretched between two posts that is heated by electrical energy to produce light. The designations of Krypton or Halogen refer to the gases contained within the bulb which have varying effect on its brightness and longevity, but in general these are still inefficient and produce a weak to moderately powerful light beam. Incandescent lamps are fragile and prone to damage from dropping and vibrations because these impacts can cause the thin filament to break, especially when the lamp is switched on. The main advantages of incandescent lamps have been their convenience and inexpensive nature. Incandescent lamps require no extra electronics or ballast to operate and are cheap to manufacture, which is the chief reason why they are still the dominant lamp in flashlights today.
The second most common lamps and also one of the newest are LEDs. LEDs are in fact not light bulbs, but rather solid state diodes. Instead of a filament, LEDs consist of a layered diode which is constructed of semi-conducting materials. As electricity is passed through these materials they emit light photons through a process called electroluminescence. This process creates very little heat which in turn means more energy is radiated as visible light rather than wasted. LEDs are the second most efficient of all flashlight lamps and can produce very strong light beams with little current draw. This has allowed LED equipped flashlights to have some of the longest rated run times on a single charge or set of batteries, oftentimes lasting for over several hours on a single charge. Because of this they are fast becoming the most popular lamp used in flashlights today and are expected to eventually replace standard incandescent bulbs as the dominant lamp type.
LEDs are also extremely rugged and resistant to environmental conditions due to their solid state design. LEDs are resistant to weather and easily sealed against intrusions by water or contaminants. They contain no breakable glass in their design. LEDs have no fragile filament in their construction which makes them very resistant to damage from dropping or vibrations. These traits have contributed to the popularity of LEDs and proven an excellent addition to flashlight technology, improving the durability and versatility of LED equipped flashlights greatly over their incandescent lamp equipped counterparts.
The least common yet most powerful of the flashlight lamps are the HIDs. These lamps, as with LEDs, produce light much differently than the standard incandescent lamp. Instead of a filament, HIDs have two electrical posts inside a sealed glass bulb that is filled with gases and metallic salts. When an HID lamp is switched on, an arc is created between the two electrical posts which in turn ignites the gases and salts within the bulb and produces a plasma reaction that emits energy as intense light. HIDs are the most powerful of flashlight lamps and can produce over three thousand lumens of intense light from a small handheld unit. This high power has made HIDs popular for use in professional grade and tactical flashlights like those used by the military and law enforcement personnel. HID’s are also very efficient and produce a great deal more lumens per watt as compared to an incandescent bulb.
Some of the drawbacks with HIDs are their high heat production and delayed startup. Some of the more powerful HID flashlights can actually burn materials that are held too close to the lamp, which makes burns associated with using HID flashlights a distinct possibility. HIDs typically require 10-60 seconds to reach full power and so are not good choices for applications that require an instant full power capability. One other problem with HIDs is their susceptibility to degradation from repeated switching on and off, and in some cases they cannot be turned back on until after having had adequate time to cool down first. Despite these concerns HIDs remain an excellent choice for applications that require the most powerful and intense lighting available that is also portable.
For overall utility, durability, longevity and power, the LED is in most cases the best all around choice. Flashlights like Larson Electronics’s LEDPL-5 LED Flashlight demonstrate all the qualities that make up a solid and powerful LED unit that is capable of fulfilling several different roles effectively while easily outperforming the traditional incandescent flashlight. With a single LED producing 200 lumens of bright white light, this light is capable of effectively working as a tactical, professional, or utility light. Small and easily carried in a pocket, this LED equipped flashlight produces a strong beam reaching up to 700 feet in length. The light is aluminum bodied and well sealed, making it extremely durable and weatherproof, allowing it to be used in professional roles such as those found in law enforcement and emergency services regardless of weather conditions.
The LED although powerful, still provides approximately 4 hours of runtime on a set of CR123A batteries and is compatible with rechargeable 18650 batteries which further enhance this lights convenience and versatility. These characteristics when coupled with the aluminum housing and the inherent ruggedness of the LED lamp results in a flashlight that is capable of withstanding significant abuse and still performing beyond expectations. A traditional incandescent lamp in contrast produces only 35-65 lumens of light, is prone to burnout and bulb damage from rough handling, and loses its most effective output within 1 - 2 hours of operation as batteries are quickly depleted of their charge.
While LEDs are not yet capable of producing the all out performance found with HID lamps, they make up for this lower output with long battery life and virtually no heat production while still outperforming incandescent lamps by a wide margin. An LED flashlight can be left on for an hour and will only be slightly warm to the touch, while an HID in contrast could cause severe burns.
As with any technology LEDs are still evolving and advancements appear on a regular basis. At this current time however LEDs are well beyond the performance of the best incandescent bulbs and offer an excellent alternative for the individual seeking a powerful and long lasting flashlight that can take abuse and still perform. Only time will tell if LEDs will eventually overtake the HID in sheer power, but the benefits in long battery life, extreme durability, and safe operation already make the LED a good alternative to the HID. There may be only three main types of lamps used in traditional style flashlights today, but only one is a true all around performer, the LED.