Flashlight technology has return a long approach since 1899 when British inventor David Misell obtained a U.S. Patent for an “electric device” using newly-invented “D-size dry cell” batteries. When he introduced the hand held light he initiated a revolution in lighting. Since then, flashlight design has created exceptional progress. Each light bulb and battery technology improved significantly, and the trend is continuing.
The Basics of Flashlights
The flashlight uses batteries that contain stored DC energy. Connecting many batteries together (in series) with a conductive metal strip, an on-off switch, and a bulb creates a flashlight. When the on-off switch or button on the flashlight is closed the circuit is complete and the bulb lights. Add a lot of batteries and a different bulb and you can realize an even brighter flashlight. The flashlight can be left energized providing continuous light till the batteries discharge. Then the light bulb goes out and you need to install new batteries to get the light back on.
A flashlight creates a beam of light that illuminates objects close or distant depending on the power and shape of the light beam. Because the distance from the flashlight increases, the beam spreads out and the illumination gets dimmer. The beam will be broad or narrow depending on the flashlight’s style, making a spot light or a flood light.
Consumers evaluate and compare flashlights by the lumens of light created, the strength (reach) of the light beam, and how long the battery will last. Size and weight have consistently been reduced so these days portable lights like these can weigh just ounces.
A flashlight will produce light output from less than a lumen to over 3,000 lumens. just twenty lumens is all the light you need to read this article in a dark room. I remember when I was a boy and it was bed time. I usually hid below the blankets reading comic books with a flashlight till I became too tired to stay awake. That makeshift light worked well in my tiny reading cave.
Flashlight Designs
Today there are many flashlight designs for sale. A visit to a local home improvement or camping supply store can show a myriad of choices.
You’ll find penlights powered by a single AA or AAA battery. You’ll find handheld flashlights sized from many inches to over a foot long with batteries that energize little incandescent or LED bulbs. And you’ll see keychain flashlights, general purpose household flashlights, spotlights, floodlights, tactical lights, headlamps that give hands-free movement, and even use-once glow-sticks that give off a greenish light for up to twelve hours. And there are multimode flashlights with switchable brightness controls that make the device bright, dim, strobe, or flash an SOS in international Morse code. I even found a few flashlights with a zoom capability and multiple brightness levels. The ingenuity of the human mind is endless.
One kind of multimode flashlight uses two double-A (AA) alkaline or nickel-metal-hydride (NiMH) rechargeable batteries and has three brightness settings—the normal setting will keep the bulb energized by alkaline batteries for just over two hours. The NiMH batteries will keep the light energized longer (about 3.5 hours). Switch to bright light and the batteries will last alittle over an hour. Set the flashlight to the lowest (dim) setting and the batteries can keep the light bulb energized for over 9 hours.
Incandescent vs. LED
Most families have at least one incandescent bulb flashlight, but light-emitting diode (LED) flashlights are quickly turning into the norm. The LED light uses less battery power, is brighter, and lasts longer than its incandescent predecessor. An incandescent bulb will turn out 8-10 lumens per watt. An LED will turn out a hundred lumens per watt, however LEDs need a lot of battery voltage to work (3.4 to 3.7 volts versus 1.5 volts for incandescent). This can be why keychain lights and small penlights still use 1.5 V incandescent bulbs.
Incandescent flashlights using alkaline dry-cell batteries have been the standard for years while tiny LEDs were used mainly as low-power indicator lights. Then in 1999 a white light LED flashlight using grouped LEDs was invented, making bright light with efficiency and run times exceeding that of incandescent flashlight bulbs. Because the popularity and use of LED flashlights continues, they’re replacing the incandescent as the practical flashlight of alternative for main use lighting.
Flashlight Performance
For emergency lighting, you don’t need the one hundred to 250 lux (929 to 2,300 lumen brightness) common to room light with full electrical power. When power is out, thirty five to one hundred lumens will usually suffice for brightness during normal use with eight to twenty lumens adequate for moving about between rooms. The idea is to use natural light during the day and emergency lighting when dark — adopting a circadian schedule whereby sleeping prevails at night and most of your activity occurs during daylight.
Once you opt on the purpose you intend for the flashlight you seek, selection is made by performance. Here you wish to know lumens of brightness, how far the light beam is usable, the type of battery and how long it’ll offer power to produce light.
In 2009, the American National Standards Institute (ANSI) revealed test and rating standards for all flashlights (FL1). Manufacturers were asked to print performance test results on the packaging. This is why you’ll often see FL1 standard values like lumens, beam range, run time, and candela with signature icons printed on the front of many flashlight packages.
Flashlight Brightness
Flashlights with brightness between one and twenty lumens are good for key chains or tiny lights. A green glow-stick produces 0.6 lumens of light. A general purpose flashlight produces thirty to a hundred lumens of brightness. A industrial flashlight will produce two hundred to three hundred lumens of light. And high powered flashlights produce 1,000 up to 3,500 lumens.
The beam or throw value describes however far the light beam can shine (in meters) before the illuminance falls to 0.25 lux (the illumination of a full moon on a clear night). By mounting mirrors in a space and shining a flashlight up towards the ceiling you can reflect the light beam and increase the overall brightness impact in the space. Reflectors are included in flashlights to focus the beam and fix the beam width angle. Angles of twenty degrees or a lot of are considered flood lights.
Run Time and Batteries
Run time describes how many hours the light will operate before the battery driving the lamp discharges to 100 percent of the voltage of a fresh battery. Several manufacturers make a graph showing light performance over time. These are typically available on their web site or product literature.
The type of battery used in a flashlight is very important in determining run time. Batteries can be disposable, rechargeable, or renewable using an external supply of energy — think solar and think manual hand crank.
Battery sorts include alkaline and lithium disposable batteries, and lithium-ion (Li-ion), nickel cadmium (NiCd), andnickel-metal-hydride (NiMH) rechargeable batteries. Lithium batteries price more than double that of alkaline batteries, however lithium batteries usually last several hours longer. Lithium batteries should not be interspersed with alkaline batteries — use alkaline with alkaline, lithium with lithium.
With the rechargeable batteries, nickel-cadmium batteries give you the most recycles (up to 1,500) followed by Li-ion with between five hundred and 1,000 cycles. NiMH batteries are smart for between a hundred and fifty and five hundred cycles.
Some consumers select emergency flashlights that all use the same kind of battery so they have a simpler stocking issue. Others opt for any sort sold in stores because they want to possess multiple choices should the stores run low. The secret’s to have an honest stock of back-up batteries on hand.
Emergency Flashlights
One widespread flashlight design that proved itself during emergency power out conditions is the headlamp. It’s also known as a headlight. This device channels light to a specific space. Headlamp batteries can turn out eleven to 120 lumens of light and last for one hundred fifty hours or more. You need brightness reaching out about seven feet for walking at night. Lithium batteries are usually not used in headlamps. as an example, the Rayovac a hundred and twenty lumen headlight uses three AAA batteries.
Headlamp/Headlight products turn out between eleven and a hundred and twenty lumens, with a reach between nine and forty meters, and a run time between five and twelve hours. They price between $14 and $20 each. Some of these have multiple modes of operation.
Flashlight choices went from 8 to 3500 lumens and reached out (beam throw) 12 to 391 meters, with operational battery lives between one and fifty hours on the brightest setting. Costs varied from $1.97 up to $70 with incandescent versions selling for much less than products using LED s.
Cell phones are another type of emergency light. According to comments on various forums, cell phones are available with flashlight capability in the 8, 12, 16, 25, 40, or 50 lumen vary of brightness — suitable for finding a hole, a light switch, or to illuminate your means through the house.
A category of lighting called “every day carry” (EDC) covers devices that are used working or emergency lights. The most popular EDC light manufacturers (in order of mention) are Fenix (23.8%), Streamlight (10.5%), Preon (5.6%), and Surefire (4.9%).
What are the most popular flashlights used by actual emergency survivors? To determine this, I read blogs and case studies covering major emergency events when power was lost for over three days. I found over sixty makers and types of flashlights, head lamps, pen lights, and lanterns being used during these incidents. I also read flashlight product reviews.to see what products are most popular these days.
Five manufacturers were mentioned the most—Fenix (13.3), Maglite (13%), Streamlight (10%), UltraFire (6.7%), and Inova (3.3%).
Survivors who ready for emergencies selected multiple styles of lighting — headlamps (one per person), little penlights or key chain lights, LED flashlights with varied brightness, beam distances and run times, and 360° illumination lanterns. By considered use of those resources, few survivors ran out of light and battery power. They used ceilings, walls, and mirrors to enhance light coverage. and they turned them on only when being used thus extending the run times out for days or weeks. a number of those survivors commented that neighbors, who didn’t prepare, usually found themselves stuck with flashlights that ran out of battery power causing them to frantically scrounge around to find or borrow replacement batteries. Failing to plan is planning to fail, and this adage showed up usually during these emergencies.
By positioning flashlights around your home so you always have access to a device, you’ll never be left in the dark more than some seconds once a power outage occurs at night. Here’s where knowledge is power—light power.
