A look at flashlights and their evolution into LED technology. The flashlight as you know it has evolved and you should be taking advantage of new improvements that will deliver better performance, longer life, and more reliability. In this post, you’ll find out what you need to know to make an informed about LED flashlights.
The invention of the handheld flashlight over one hundred years ago and its subsequent improvements ushered a new era of convenience and safety to anyone that needed to light their way. Over the last decade the flashlight has been transformed by a technologic revolution.
The use of LED technology in place of the standard incandescent bulb has resulted in a handheld lighting device that is brighter, longer lasting, and more versatile. A comparison of standard flashlight technology and LED flashlight technology reveals many factors that make the LED the new champion of flashlight technology.
Standard flashlight technology typically uses a tungsten filament incandescent bulb which creates light by heating a suspended thin filament until it glows. This creates a great deal of heat while producing a yellow light. The inefficiency of this process requires heavy battery use and the suspended filament is very fragile and prone to breaking.
Additionally, the light beam put out has varying levels of illumination from the center of the beam to its edges. Another disadvantage of the standard flashlight, is that the light output decreases as the batteries are drained reducing effectiveness over the life cycle of the cells.
LED Light Emitting Diode
The Light Emitting Diode (LED) on the other hand, uses a charged semi-conductor material wrapped in a clear solid resin to create light. The light is created when an electrical current changes the state of the material by an exchange of electrons. This process requires less energy and its greater efficiency results in a light that is much brighter and more evenly distributed than a standard flashlight allowing the beam to be seen much greater distances.
In addition, the light produced is a white light that more accurately mimics daylight allowing for greater detail in the light zone. The solid resin covering of the LED also serves to protect it and this shockproof design vastly increases its durability over incandescent bulbs with their fragile suspended filament.
What is a Lumen anyway?
There are a couple of ways that flashlight output can be measured. Lux is often used and measures the amount of light that strikes a surface. This can be a decent rough overall measure when comparing two similar lights but doesn’t take into account the different beam patterns that exist in flashlights and becomes misleading when comparing light from a flood type of beam versus a spot type of beam.
Lumen is the most accepted and accurate measurement for our purpose. It is a measure of the total light emitted and can be used to compare flashlights as well as other types of bulbs. An important consideration when interpreting the lumen number is whether it is emitter lumen or ‘out the front’ lumen. Emitter lumen specifications are the highest output directly from the LED emitter or bulb before it travels through the lens of the flashlight. There are some inevitable losses of output from the flashlight reflector and lens that must be considered. If possible, and ‘out of the front lumen’ value will be the most accurate and fairest method of flashlight output comparisons.
Although it is hard to make a fair comparison between lights of different type and configuration, a general result of the efficiency of LEDs gives them an output of around 25-60 lumen per watt while an incandescent bulb will produce between 14-17 lumen per watt. That means that for the same battery input, LEDs will convert on a more efficient scale.
The durable and efficient nature of the LED unit results in battery life that is ten times greater on average over standard flashlights. Some LED flashlights also utilize electronic controls that provide multiple levels of light depending on need which increases efficiency and further extends battery life.
Also, many LED Flashlights have controls which maintain full light output up until the very end of battery life. Another advantage of this greater efficiency is that effective LED flashlights can be made much smaller than standard flashlights and still produce practical effects.