Bike Illumination is the illumination attached to the bike with the aim above all, along with the reflector, to increase the visibility of the bike and its rider to other road users in poor ambient lighting conditions. The second goal is to illuminate reflective materials such as cat's eyes and traffic signs. The third goal may be to illuminate the road so that the rider can see the way forward. Serving the latter purpose requires a much lighter flux and thus more power.
Many jurisdictions require one or more bicycle lights to be mounted on bikes that are driven at night - generally white lights in front and red lights behind.
Video Bicycle lighting
History
The earliest bicycle lights were oil-powered and began to be produced in 1876 for Ordinary (High-Bicycle) and dense-tired rickshaws. From 1896 acetylene gas lighting to bicycles began to be introduced and then in 1899 the acetylene gas lamp for the cars became popular. Their carbide lamps are powered by acetylene gas, produced by combining calcium carbide with water. The light provided is very bright but the lights require routine maintenance.
Since the beginning of 1888 electric-powered bicycle lights were manufactured but did not become a viable proposition until 1898. They consisted of incandescent light bulbs and lead-acid batteries or dynamos. Lead-acid batteries are replaced by dry cells and then by alkaline batteries. Dynamos improves efficiency and reliability, recently incorporated into wheel hubs, for example. Mold techniques for plastics are also improved, allowing optical lenses to be repaired and reduced costs. The incandescent lamp is replaced first by the halogen lamp of the closed unit and then by the high light output emitting diode.
Maps Bicycle lighting
Lighting system
Electrical system
Batteries, either rechargeable or disposable, are often used for powering electric bicycle lights. Where the unwanted battery, a magneto is used. In a cycling circle the device is called a dynamo even though the device does not have a commutator. See the Dynamo system section for details.
Voltage
3 volts: Often supplied by 2 AA or C/D batteries.
6 volts: Sometimes 4 AA batteries are used; also supplied from bottle-shaped batteries or hub dynamos, and lead-acid batteries
9 volts: Sometimes supplied by PP3 batteries
12 volts: Most of them are supplied by sealed lead-acid batteries. The main advantage with this voltage is the versatility of electrical systems, such as the ability to charge the mobile phone with lighter cigar containers because cell phones are now becoming increasingly common among users, although 5 volt USB is also used for that purpose as well.. It also allows electric air compressors to repair a flat tire. Some 12-volt dynamo are also available, although the wattage rating is less powerful for medium to high wattage applications.
Light source
The simplest bike light uses a filament tungsten incandescent lamp or a halogen incandescent lamp. LED lights and high intensity discharge lamps are also used.
Legal requirements
Under the Vienna International Convention on Road Traffic (1968) of the United Nations, bicycles are vehicles. Article 44 of the Convention provides that: "The engineless cycle in international traffic shall be: (c) Comes with a red reflector on the back and with the device such that the cycle may indicate a yellow or selective white light forward and a red light to the back. "In some countries, such as France, it may be a violation even to sell bicycles that are not equipped with an appropriate legal lighting system. Germany requires that all bikes more than 11 kg are equipped with appropriate dynamo lighting systems, but even light bikes must be equipped with lights (battery powered lights are allowed) except during races. However, not all countries apply this requirement to cyclists.
Many jurisdictions require that the bike be fitted with a reflector at the point of sale. In the United States, this is governed by the Consumer Product Safety Commission. Suitable CPSC reflectors (also commonly installed in other markets) have three retro-reflective panels positioned at an angle of 30 °. This standard requires a front-facing white reflector on the front of the bike, a white reflector facing sideways on each wheel, a red reflector mounted on the back, and a yellow reflector mounted on the front and back of each pedal. Some people interpret this as a cyclical night cycling endorsement only.
Many jurisdictions require the use of headlights and taillights or reflectors after dark. Most European countries and some US states require front and rear lights at night, while others allow the reflector only on the back. Some jurisdictions impose conditions on the light output and size of the lens and reflector lenses; some require compliance with standards set by third parties; some just specify the minimum distance from which the lighting device should be visible. In some jurisdictions like Germany and the Netherlands, flashing red lights are illegal, in others they are allowed.
In Britain, the rules governing bicycle lights are set out in the 1989 Road Safety Illumination Law and subsequent amendments, summarized in the Highway Code. The rules require white headlights, red rear lights, red rear reflectors, and yellow/yellow toy reflectors on the front and back of both pedals. Reflector must conform to BS 6102/2 or equivalent European standard. The situation for lights is more complicated:
- light in stable mode is deemed to be approved only if it complies with BS 6102/3 or equivalent European standards;
- light without stable mode is deemed approved only if it blinks at a constant rate between 60 and 240 flickers per minute and has a light intensity of at least 4 candela;
Most of the available LED lights are not approved for use in the UK because they have a stable mode that is incompatible with BS 6102/3. However, it is legal to customize additional lights by providing the correct color, they do not fascinate other road users and that if they blink, they do so at a constant rate of between 60 and 240 flash per minute.
National cyclists organizations such as LAB (US) or CTC (UK) are a source of information on lighting.
Security
The use of lights for night riding is generally recommended or requested by the authorities as a basic safety precaution, even in fairly bright urban contexts. Studies show a correlation between collisions and failure to use lights even during the day.
It is estimated that 75% of bicycles used in the United States at night do not meet the legal requirements for lighting. In countries where bicycles are widely used for travel and short trips, such as the Netherlands and Scandinavia, bicycle head and bicycle head regulations are strongly enforced by the authorities. However, a study from 2013 showed that different lighting regulations seem to have little effect on the rate of bicycle accidents, and indicate a lack of studies on the safety benefits of bicycle lighting.
Front lighting
LED light
White LEDs have a higher luminous efficacy than halogen lights and are strong enough to provide the front light for the bike. Models are available with output ranging from several lumens to high powered units that produce as much light as an automotive headlamp, suitable for high speed usage on dark roads.
LED systems often include the option to dim the LED, or to provide a blinking light.
While disposable primary batteries may be a low-cost option for intermittent use, regular bike commuters may find it cost-effective to use rechargeable cells. Some pretty bright headlights use a lithium-ion rechargeable battery pack, which can be recharged from a USB port.
The low power LED light is mainly for viewing, or as an emergency backup, and is the dominant choice for taillights. The colored LEDs provide more light than incandescent lamps with filters, which absorb a lot of energy visible from the bulb. The rear marker LED light can be operated on single-use coin cells.
Cheap battery light
Cheap battery lights can be a good choice for occasional use, and usually meet legislative requirements.
Flashlight
There are some high-powered flashlights with rechargeable lithium-ion batteries. Although not specifically designed for bicycle use, this is a viable alternative to halogen lamps that can be recharged. They can be tied to a bicycle handlebars with various mounting devices such as block locks. The round light pattern of the general purpose flashlight is lower than the properly formed bike headlights to illuminate the road and does not give excessive glare to the incoming traffic.
Halogen lamp
Although these lights were originally designed for off-road use, where they are almost universal, rechargeable halogen lamps became popular with commuter bikers.
The lights used by most halogen refill systems are cheap, bright but simple enough: they project light cones (wide and narrow beam options available) that are good for off-road use but are not ideal for road use as they can dazzle the approach of road users. This is why rechargeable halogen lamps do not meet the legal requirements in some jurisdictions.
Many systems use standard commercial prefentif optics, making various combinations of available strength and beam widths available. Most systems allow simultaneous connections from different lights - for example, wide and narrow beams for off-road riders, or high-and low-power rides to ride the road.
Lampu HID
High-intensity discharge (HID) lamps are the brightest lights available for bikes to date lost due to advancements in LED lights. They are very efficient, very bright, but expensive. They also tend to have high power consumption (although they use less power than halogen for higher output), so the combustion time is relatively limited. Otherwise, they have the same advantages and disadvantages as a halogen system that can be refilled, and like a halogen system, they are designed primarily for off-street use, have symmetrical rotational beams that produce a lot of down-light. An additional disadvantage compared to halogen or LED lights is that HID lamps do not tolerate recurrent strikes, and in many cases do not light up immediately after shutting down. Likewise, if the battery level falls too low, the light will die rather than dimming. But battery life that is longer than halogen tends to negate this problem, because many drivers simply turn on the lights and let it run along the way.
If using a HID lighting system on the road, the lights should be adjusted to avoid dazzling traffic.
Backlight
Filament lamp
The only real advantage to this is that they are often omnidirectional, a useful quality in running lights that must be visible through a very wide arc. The newer LED lights have this feature, even eliminating this final advantage. Energizer once made a 2.4W halogen rear light bulb, which is basically a headlamp with a red lens, but most taillights only need about 0.5W.
LED
Most LED lights will work in either flash or stable mode. Some LED lights have many LED banks that allow the light to blink and stable at the same time. This can also be achieved by having one flash and one stable.
In many countries, LED flash is the norm for taillights. In other countries such as Germany and Netherlands flashing lights are prohibited by law. In blinking UK LEDs (front and back) is legal from October 2005, provided the lights are in compliance with current Road Lighting regulations requirements. Many vendors claim EU compliance, but this does not provide consistent security or legal value across the Union.
The most common resource for rear LEDs is a set of alkaline cells and rechargeable cells. In both cases, the battery tends to fail quickly when running; it is widely considered a good practice to have two taillights if the battery fails on the way.
Advantages of LED backlight
- Compared to incandescent lamps, service life is virtually unlimited
- Light
- High luminous efficacy
- Cheap
- Usually the choice is blinking or stable
Xenon lights
An innovation in bicycle lighting, although common in industrial applications, xenon lights are brighter than LEDs and are used by some as back lights.
The advantages of the xenon lamp
- Very bright
Disadvantages
- Relatively expensive
- High power consumption (short battery power)
- Lights require frequent replacement
- Intense light can be a serious irritant to other road users
- Short flash followed by darkness, can interfere with night vision and make judgment of cyclist's position difficult.
Power supply
Battery
The introduction of low self discharge NiMH batteries (LSD-NiMH) in 2005 made AAA and AAA rechargeable batteries more feasible to turn on LED bike lights. Previously, the self-discharge effect of NiCAD and NiMH batteries caused the battery to decrease for several weeks or months, even when not in use. This is especially a problem for low power LED lights, and for users who only use occasional bike lights. The LSD-NiMH battery greatly reduces the self-discharge effect, allowing the battery to store its charge for a year or more.
For higher-powered lamps, an external battery of 12V VRLA batteries is often required. This battery pack is usually tied to the top of the frame tube, or shaped like a fit in a water bottle cage, or it can be placed in a basket. The cable connects the battery pack to the light. Another advantage with battery power (especially with 12 volts) is the ability to turn on other components outside the lighting, as well as all from one battery (as long as they run safely at 12 volts) even though splice spaghetti from splicing can become a setback depending on how complex the electrical system is.
Alternatively, Li-ion and LiPo batteries have become more popular with cyclists due to their higher capacity and lighter weight compared to conventional batteries. More specifically, the 18650 battery, which has been popular with electric car manufacturers (for the same reason) and is commonly found in laptops and flashlights.
Dynamo System
Dynamo system does not require batteries and can be installed permanently to the bike.
Dynamo bikes are actually magnetos and generate alternating current.
Type
There are three main types:
- Hub dynamos is built into the front or back wheel hub. These are generally the most reliable and most efficient of the three types.
- The bottle dynamo (or the front dynamo ) is attached to a seatstay or fork and is rotated by a small wheel in contact with the tire wall. It's easier to retrofit than the hub dynamos, but tends to slip, especially in wet conditions.
- The bottom-bracket dynamo is attached between the chainstays behind the bottom bracket and powered by a roller against the tire. It's easy to install and does not wear sidewall.
Other types of dynamo exist, but less common. For example, there is a dynamo attached to the fork and driven by the radius.
Output and optics
Dynamos are generally limited to about 3 W of output power, although the best 12V hub dynamos can produce 6 W at a speed A bottle of dynamo will slip if run at twice the nominal power, the dynamo hub does not have this problem.
At the speed the dynamo can beat the lamp, causing it to fail. Historically this is a nuisance, but modern lights and dynamos often incorporate Zener diodes to prevent overload, and the dynamo can be designed to saturate beyond a certain voltage to protect the lamp.
Good dinamos can achieve up to 70% efficiency (that is, under 5 W of rider output diverted to generate 3 W of power) and provide good light output at low speeds.
To generate light when the bike is stationary, some dynamo lights have a stand-alone facility, usually a blue-white (headlight) or red (backlight) light powered by a capacitor, which runs for about five minutes.
Advantages of dynamo lighting
- Usage time is not limited by battery life
- No need to charge or replace required battery
- More eco-friendly and inexpensive to run than battery-powered lights
- Usually do not have to be deleted when the bike is parked
Losses
- Does not provide lighting when the bike is moving very slowly or discontinued, unless the system is equipped with a capacitor or backup battery
- Maximum power output gained is lower than with battery
- Difficult to remove by owner if this is necessary to prevent theft or vandalism, or use it on more than one bike
- Replacing the bike is harder because installation is more difficult (because lights and resources are separate)
- The inexpensive or less harmonious dynamo produces clear obstacles
- The dynamo and the old lamp do not limit the output voltage, which causes the initial failure of the incandescent light bulb in the lamp. Modern lamps and dynamos contain voltage dividers to solve this problem.
- Not suitable for high power applications outside lighting, unless designed to charge on-board battery.
- The bottle dynamo may be noisy, difficult to adjust, can slip in wet conditions, and may wear tire sidewall
Magnetic light
Lights can be self-powered through electromagnetic induction, eliminating the need for a battery or dynamo system. The advantage is similar to the dynamo lighting. The most common designs include a magnet on the spoke wheel and a lamp with a coil in it, mounted on a frame or fork bike. More exotic designs exist; some have magnets and lights mounted on wheels, or magnets and inductors in a single casing, utilizing eddy currents.
Additional lighting and visibility.
Headlamps
The headlights are a useful addition to the bike lights. They can be directed without directing the bike, providing useful filler lighting especially on bad or very dark roads. They have additional security benefits by positioning a higher light on cyclists to increase visibility. They also allow the user to read the direction and road signs placed at high signs. However, because the high positions of glare light can dazzle the incoming traffic.
Some rechargeable systems offer a supported headlamp option from the main battery.
High reflective and visibility materials
Retro reflective materials, in the form of fixed reflectors, reflective bands, and reflective clothing, are useful in making cyclists visible to other road users. Reflective materials can be applied to bicycles, riders, or suitcases; Also, tires are available with reflective side walls. Reflection is only visible when in the beam of lights, and even only within a narrow locus. Importantly, they did nothing to illuminate the path . Reflector is not replacement lamp, but is an important supplement for portable lighting.
On the bike
Reflector and reflective tape provide additional visibility (especially when applied to moving parts of the bike) and is required in many jurisdictions. The pedal reflector is particularly visible following traffic as it moves up and down; unfortunately they are not compatible with most clipless pedal systems, although adapters are available for some, especially older SPD models, and some one-sided designs are available with built-in reflectors. In England, where the front and rear pedal reflectors are required after dark, most cyclists with clipless pedals ride illegally. Law is rarely enforced, but is potentially used in court to reduce financial compensation if cyclists are hit by other vehicles. CTC has suggested that requirements should be revoked if the cyclist matches the additional rear reflector or illumination, but this does not change in the latest revision of vehicle lighting laws in the UK (which allows LED blinks). The recumbent bike rider has shown that the pedal reflector requirements do not make sense to them, because the reflector points straight up and down in use, and is not visible from other vehicles. In 2008, California legislation allowed white or yellow shoe reflectors (front and back), or reflective bracelets, instead of the pedal reflector.
Clothing
On a dark road, a retroreflective material like 3M's Scotchlite will appear boldly on the headlights of the car.
The color of the lighting should be checked in the rider's environment. One solid color can disappear under artificial light, especially yellow sodium vapor lighting, and color blindness is common; red/green colorblindness can make the yellow neon disappear with a green background (hedge or grass), although people with green red/colourblindness deny this. A vest with yellow and orange neon areas and reflective widths may be the best solution.
In several times the electroluminescent apparel has been available to add the existing array to the LED arm tires and helmet blinkies.
Wheel-mounted light
Lamp mounted on the wheel is used to increase the visibility of the bike from the side. Due to the persistence of vision, individual lights mounted on the radius of a moving bicycle wheel are regarded as bows or luminous circles. There are lights that are controlled with MCU that are capable of displaying colorful or animated patterns. The shining rim or wheel can isolate the bike from the visual noise of the city lights and help the driver see and immediately recognize the cyclist. Such lights are mainly battery-powered, but battery-free designs also exist.
Light output size
Four units are commonly used to describe the light output of commercially available lighting devices:
- electric power, in watts, but this is a poor measure because it reports consumption than actual light output;
- the light intensity of the jet in a certain direction, in candelas, is a better measure of the output of light in the focused beam;
- the total luminous flux transmitted in any direction, in lumens is a better measure of the light output than non-directional light; The lighting
- provided for the road at a certain distance is the measure of how much light illuminates the path.
Power consumption in watts
Watt (W) is the unit of power, and is usually quoted for the input of electrical power, not the power output of light. Electrical power is the product of voltage and current (watts = volts ÃÆ'â € "ampere). Input power is only useful when comparing similar technology lights. The 3H W halogen diagonal light will illuminate the same ramp with a rechargeable light of about 7-10 W, but recharge typically emits more light to the side, which is useful on the track (although wide and narrow beam versions are available). The 3A LED lights are brighter than halogen lamps but are generally less focused. HID lights emit large amounts of light and are often quoted in terms like 80 'W equivalent halogens.
The intensity of light in a particular direction in candelas
The candela (cd) is the SI unit of light intensity, ie strength per unit of solid angle in a particular direction, weighted according to the sensitivity of the human eye to the various colors of light. Typical candles produce light with about 1 candela of luminous intensity in all directions. Lights can produce higher light intensity either by generating more light, or by focusing more densely. The brightest light intensity depends on many factors, including the color of light and the sensitivity of the eye to that color, the optics involved, the reflector, and the lens. Regardless of the complexity, it is a more useful measure than watts, because it defines how much light can be used spilled somewhere: the dynamo lamps designed for road use and focused on seeing the road make light lamp usage more efficient. of the lamps using symmetrical rotational optics.
Total luminous flux in lumens
Lumen (lm) is the SI unit for the luminous flux, the total amount of light emitted by the source, which is weighed according to the sensitivity of the human eye to the various colors of light. Lumens per watt is a common measure of the efficacy of light sources. The luminous flux is less valuable for bicycle lighting because of the importance of directionality. Luminous intensity is much more useful, but lumens per watt is an easy way to compare the output of similar light.
Lighting at a certain distance in lux
The lux (lx) is the SI unit for illumination, ie the amount of light that illuminates the surface (road, in the case of bicycle light) per unit area at a particular point, weighs according to the human sensitivity of the eye to various colors of light. Some manufacturers point to the illumination that their headlights provide to the road at the point that is located to the right of the bike in front of the standard.
References
External links
- Current Bicycle FAQ page
Source of the article : Wikipedia
0 Comments