- An LED is a semiconductor light source that reacts to electric current passing through it by emitting a bright light.
- LED bulbs are vastly more efficient than traditional bulbs, consuming between 75 and 90% less energy, while also lasting a lot longer.
- Batteries, when simply thrown away with other household rubbish, can have a deadly effect on your local environment.
For security personnel, a reliable LED torch with a full, bright beam can be an invaluable instrument of personal safety, even as it enables better job performance. An inferior model, on the other hand, may cause its user all manner of unforeseen problems.
If using a hand-held torch is part of your job, you’ll know that there is no better option on the market right now than an LED torch.
In this handy guide, we’ll be taking a detailed look at these lovely little light-givers. What are they made of? How do they work? And what should you look for if you’re thinking of buying one.
So without further delay, let there be light!
How LED Torches Work
LED, as you probably know, stands for Light Emitting Diode. An LED is a semiconductor light source that reacts to electric current passing through it by emitting a bright light.
This light can appear in a wide variety of different colours, but white light (the kind we’re focussing on in this feature) is accomplished either via the use of multiple semiconductors, or a layer of light-emitting phosphor contained within the device itself.
LEDs are different from traditional incandescent bulbs because they produce light differently. Where LEDs produce light via a semiconductor, traditional light bulbs do so by passing electricity through an electric light filament. This also differs from energy saving bulbs, which use mercury vapour to produce UV light.
A Little Bit of History
British inventor David Misell invented the first torch (or ‘flashlight’ to our American cousins) in 1898. One year later, he received the patent. Prior to this, potentially dangerous items such as wax candles and kerosene lamps had been used to provide light.
Misell’s invention would not have been possible without the prior invention of the first dry cell battery (by the German Carl Gassner in 1888), so the inventions of both the battery and the torch go hand in hand.
Today’s LED torches have not changed dramatically from these early models, though performance and functionality have been improved considerably.
British radio researcher (and assistant to Marconi) Henry Joseph Round first discovered electroluminescence (the production of light by the flow of electrons) in 1907. A decade or so later, another radio researcher – this time Russian – named Oleg Vladimirovich Losev documented the electroluminescence that was coming from the diodes in his radio set.
Then, in the early 1960’s, Losev’s observations inspired Americans Robert Byrd and Gary Pittman to create the first LED (an infrared version not visible to the naked eye) as a by-product of their search for an LED laser.
In 1962, American engineer Nick Holonyack finally put all the pieces together. Holonyack created not only an LED laser, but also the first visible light LED.
Years later, in 1999, the first high-powered LED torches became available. The Lumileds Corporation of San Jose, California designed and built these early LED pioneers.
LEDs or Regular Bulbs, Which is Better?
LED bulbs are vastly more efficient than traditional bulbs, consuming between 75 and 90% less energy, while also lasting a lot longer.
Additionally, the light from an LED bulb disappears almost as soon as you switch an LED light off, while other bulbs can dim slowly and then take a while to completely shut off. When LED bulbs are reactivated, the light comes on instantly.
LEDs also work perfectly well at lower temperatures, something that cannot be said for other portable light sources.
On the downside, LED bulbs are considerably more expensive than other bulbs, although the prices are coming down rapidly, making LED technology more accessible than ever to even the most cash-conscious consumers.
Some people do not like the light emitted from LEDs, complaining that it has a colder ‘bluish’ quality than the warmer tones given off by traditional bulbs. In terms of torchlight, this probably won’t be the deciding factor in anyone’s purchase, but it is worth mentioning nonetheless.
Overall, it is definitely fair to say that LED torches are significantly better than most, if not all, other options.
How Long do LED Torches Last?
A good LED can last for an extremely long time, perhaps as much as 25 – 30 years. Of course, this does not factor in accidental damage or carelessness on the part of the user.
In terms of battery life, most LED torches are battery powered, taking batteries comparable to the size of the torch itself. The larger models tend to run on ‘D’ batteries (commonly referred to as ‘flashlight batteries’). These will be discussed in greater detail later on in this feature.
Smaller models might use smaller batteries, such as double or triple A. Ultimately; battery life depends on the quality of the batteries themselves, as well as the energy efficiency of the device used and the frequency of usage.
Battery life may vary from torch to torch, but the LEDs are still the longest lasting form of man-made illumination there is. A good LED torch should, if well kept and looked after, last for many years.
The Components of a Torch
Most torches are cylindrical in shape. The main exterior part of the torch is referred to as the case. The case not only protects the torch’s inner components, it also gives the device its shape.
Some torches feature a handle on top of the case, however most are simply handheld, meaning that the handle is incorporated into the overall design, sometimes via the inclusion of a rubber or plastic grip.
The switch, which can be located almost anywhere on the device, is the element that completes the transfer of energy from the batteries to the bulb.
The bulb (or ‘lamp’) is the area at the front of the torch that emits light. This can be a tungsten filament bulb or an LED bulb. The shiny area around the bulb is usually called the reflector. The reflector is fashioned from plastic and coated with a shiny layer of aluminium that directs the light rays forward to create a steady beam.
In front of the bulb is a layer of clear plastic referred to as the lens. The main job of the lens is to protect the bulb, which is usually fashioned from thin glass.
If we imagine ourselves to be unscrewing the head of the torch and peering inside the case, we will see the batteries.
Once the batteries have been removed, the contact strips will become visible. Contact strips are made from copper or brass and are located throughout the device. These thin slips of conductive metal complete the connection between the batteries, the bulb and the switch. The contact strips usually rest upon a small spring or thin piece of conductive material.
Once the switch is turned to the ‘on’ position, it allows the passage of electrical energy to take place from the batteries to the bulb, creating a basic circuit. When the switch is turned to the ‘off’ position, the circuit is broken, which causes the light to go out.
This section effectively describes the component parts and inner workings of most torches, though some models may vary slightly from this description.
Types of Batteries used
The batteries most commonly used in torches are ‘D’ batteries. In fact, D batteries are so closely associated with torches that they are sometimes known as ‘flashlight batteries’.
Smaller torches, of course, will use smaller batteries (with AA and AAA being the most popular). However, we will be focusing mainly on D batteries for this section.
D batteries are dry cell batteries that measure around 3CM in diameter and 6CM in length. They usually weigh between 160 and 180 grams. They are available as both non-rechargeable and rechargeable models. Like most other batteries intended for domestic use, D batteries carry a charge of 1.5 volts.
A standard D battery might produce a current of around 10,000 mAh (milliamps per hour). As the name suggests, a milliamp is one thousandth of an amp. How long the battery lasts, then, depends on the device’s current consumption rate.
You might wish to check the batteries you buy for an ‘Ah’ rating. An ‘Ah’ of ‘amp hour’ rating tells the consumer how long the battery is likely to last if the power were to be drained at a basic rate of one amp an hour. An Ah rating of 3, for example, means that the battery would last for three hours if drained at this rate.
The Ah rating is really only used to compare products, however. It is not a reliable measurement in most other circumstances as every device is different.
All alkaline batteries, including D batteries, can become very warm if used over a prolonged period of time. Between their high charge and the steady increase in temperature, it is possible for these batteries to leak alkaline fluid inside the torch itself. Alkaline fluid is quite corrosive and, in addition to severely irritating the skin, it can completely ruin the inner workings of your torch.
To avoid this, it is advisable that you do not store your torch in a high temperature environment (for example, the attic or loft space of your house. Although it is convenient to leave a torch up there, the hot temperatures of summer greatly increase the chances of battery leakage).
It is also a good idea, if possible, to remove the batteries when the torch is not in use. If you use an LED torch for work, for example, take the batteries out when you get home and only put them in again when your next shift starts.
You should also avoid mixing battery brands if possible and never use batteries that appear to be misshapen or dented. You might also consider switching over to rechargeable NiMH batteries, which are far less likely to leak.
Ultimately, all alkaline batteries can potentially leak and there is no way to be 100% secure against battery leakage. However, the methods listed here will greatly minimize the chances of this occurring,
If you are intending to use your torch regularly, you will also be replacing the batteries fairly often. In this case, please locate a site that will recycle them. Batteries, when simply thrown away with other household rubbish, can have a deadly effect on your local environment.
Batteries contain at least one of the following metals: lead, zinc, manganese, nickel, cadmium, mercury, silver and/or lithium, all of which are potentially toxic. This is in addition to dangerous acids that are also present in batteries.
As batteries break down in landfill sites, they can leak these and other pollutants into the atmosphere, which causes air pollution. They can also seep into the closest water supply, which affects not only the wildlife that depend on that water supply, but also human beings who may, as a result, unknowingly ingest contaminated water. When you consider how many batteries are being thrown away each year, this becomes quite an alarming notion.
As of 2010, any UK shop that sells more than 32kg of batteries per annum (around 345 4-packs of AA batteries) is legally obliged to provide battery recycling options to its customers in-store.
Accordingly, many local supermarkets and other businesses offer free battery recycling services. Take a minute to find the one nearest to you and make use of it.
Different Types of LED Torch
There are a lot of different types of LED torches in use today. These include rechargeable models, where rechargeable Lithium-ion batteries replace traditional batteries.
In terms of outer design, there are small, portable models such as penlights, clip and keychain torches. There are also right angle torches (which are often adjustable and used for hands-free work), flexible torches (which are good for a variety of uses and positions) and body or head-mounted torches.
Tactical torches, for their part, are tough, durable models designed for military and police use (they are also sometimes used by security services). Among the most solid models used today are Maglites. These tough torches were the brainchild of American inventor Tony Maglica, Maglites were developed for use by the Police force, who found traditional torches too easily breakable.
Maglites have subsequently been in-use, in various disciplines and capacities, since 1979. A key design point of a Maglite torch is the adjustable head, which allows it to blast a wide beam of illumination or focus solely on a small area (the benefits and drawbacks of this will be discussed later on in this feature).
The Materials Used in Torches
Although some high-end torches can be fashioned from plastic, many torches are made from aluminium, the same material from which drinks cans, tin foil and bike frames are made.
Aluminium is lightweight and therefore practical for hand-held or body-mounted items. It is not especially tough, however. Accordingly, a lot of aluminium torches make use of a type III hard anodizing.
Anodizing is an electrochemical process that involves adding a finish of anodic oxide to nonferrous metals such as aluminium, titanium and magnesium. This makes the metal much more durable as well as far more able to resist corrosion or damage.
Sometimes, the case will also be coated in a thick layer of rubber, which in addition to acting as a form of insulation, can provide extra impact protection and improve the user’s ability to grip the torch while in use.
The bulb itself is usually fashioned from thin glass, while the lens will be made from a thick, clear plastic. All materials can vary from model to model, however.
Of course using a torch as a weapon, is frowned upon, but in the case you need to use it for self-defense, the heavier and better made torch will give you better protection.
Resistance Ratings and Prevention of Breakage
Most torches have an impact resistance of around 1.5 metres. The term ‘impact resistance’ describes an item’s ability to withstand a sudden impact. In the case of devices such as torches and smartphones, an impact usually occurs as the result of the item being dropped.
The average British man stands at around 1.75 metres tall, while the average woman is around 1.61 metres. This means that an adult, whether male or female, can adopt a standing posture and drop a torch with a 1.5 metre impact resistance without seriously damaging it. In order for any serious damage to occur, the user would have to be holding the torch fairly high, perhaps near their chest or head.
Many modern devices are referred to as being ‘waterproof’ or ‘water resistant’, however, it is worth noting that every device has a point whereby water can get inside and ruin it. It could be the temperature of the water, the length of exposure, the depth or even manipulation of the device while it is submerged, but whatever protections the device may or may not have, water ingress always holds the potential to cause irrevocable damage.
In the case of any technology you plan to use outside or near to water, it is worth examining the IP (or ‘ingress protection’) rating. In simplest terms, an IP rating explains how water or dust-proof the device in question actually is.
An IP rating features two numbers from 1 – 6 (‘0’ or ‘X’ means that it has no score and offers no protection). The first number describes the device’s ability to resist dust, dirt or small objects.
If the first digit is 1, for example, it means that the camera is safe from penetration by objects larger than 50mm in diameter. A rating of 6 tells the user that their device is basically dust proof.
The second digit of an IP rating rates the device’s resistance to moisture. A rating of 1 tells you that the device can be safely used in the rain, while a rating of 8 means that the device will function properly even when fully submerged in water.
Light beam patterns differ from torch to torch, both in terms of brightness and beam size. There are informal, but somewhat apt names for these different kinds of beam patterns. Each type is, of course, suited to a different activity, so it pays to have at least a passing familiarity with them all.
- ‘Floody’ light beams illuminate a wide area, but do not throw light over particularly long distances. This type of torchlight is very useful for lighting up an entire darkened room, where longer-range torches will simply illuminate whatever specific point they may be directed toward. This is a good type of light for head torches and anything you need to see close up.
- ‘Throwy’ beams throw up a long-range light with a tight hotspot. Not especially suited for close-up work, these beams are very good for seeing people or objects that are relatively far from the viewer. They are also very good for lighting up dark tunnels and caves.
- ‘Zoomy’ beams are well known to users of Maglites. Zoomable light beams purport to offer the best of both worlds. The reality, perhaps sadly, is somewhat different. Zoomies don’t illuminate as broadly as floodies and don’t focus as keenly as throwies, so, whilst they are convenient in certain situations, zoomies tend to underperform when it comes to specialist usage.
The brightness of zoomies can also dim considerably when the light beam is at maximum zoom in either direction. Zoomies are also at a greater risk of water ingress, since the head adjusts like a camera lens.
These torches are however pretty useful for basic home use, where their versatility can really come in handy. Zoomies are also highly prized by both artists and photographers, as the ‘zoom’ function allows them to manipulate their light source in order to create the right look for a particular image.
What to Look for in a Torch?
If you work in security, or any other field that may require you to operate by torchlight, then you owe it to yourself to purchase a dependable torch of relatively high quality.
However, it isn’t at all necessary to buy the best torch on the market (and spend a lot of money needlessly in the process). An LED torch capable of being used professionally should ideally:
- Be fashioned from a durable substance such as hard wearing plastic or specially treated aluminium.
- Have a light output of around 1000 – 15000 lumens.
- Have a beam pattern specifically suited to the duties for which the torch will be used (for example, a long-throwing beam is useful if you work outdoors at night or in a large area with low light).
- Have an impact resistance of at least 1.5 metres.
- Operate via rechargeable batteries (this is cheaper over the long term, not to mention much better for the environment).
- Have an IP rating of 44 or greater.
- Feature a design well suited to the tasks for which it will be used (i.e. body mounts or portability).
- Be covered under warranty or guarantee from the manufacturer.