Cycle days. Not a day without a bike!
Bicycle light. Choosing a bike light
For the convenience and safety of cycling, in the dark, you need to equip your steel pet with a high-quality bicycle light. Indeed, on the streets of many settlements, outdoor lighting is often absent. What, then, can we say about village or forest roads? Considering that the bike rides quickly and quietly, you can hardly hear it on the streets of a noisy city, and when you can hear it, it may be too late. The cyclist and his vehicle must be clearly visible from afar. Ideally, when driving along a motorway at night, a cyclist should look like a Christmas tree escaping from a children’s party.
I told about my flashlight with Aliexpress here:
A bicycle light must have a rigid attachment to attach it to the handlebars or other parts of the bicycle. A high-quality lantern provides strong illumination of the required shape and a good spectrum of the light spot. Not the last factor of work is its economy.
Bicycle lights have come a long way since the mid-19th century. At the beginning of their procession, they were oil and candle. And having reached the end of the 20th century, they began to be equipped with krypton, halogen and xenon lamps. There are compact and energy-consuming batteries for them. But, despite the achievements and the emergence of new technologies, some problems remained unresolved. The incandescent lamps used in bicycle lights, emitting more light, began to consume significantly more energy. And even the use of halogen incandescent lamps does not make it possible to use a bicycle lamp for more than 3-4 hours.
To date, the most widespread are bicycle lights with an internal arrangement of batteries. An incandescent lamp in an expensive and high-quality lantern is most often halogen, with a power of 2-3 W. Cheaper flashlights use incandescent argon or krypton bulbs. Their light characteristics, of course, are worse than halogen ones, but they give quite acceptable lighting. The disadvantage of using such lamps is the high power consumption. The highest illumination of the road and a longer operating time are provided by bicycle lights with external batteries of increased capacity. Due to their relatively large weight, they have to be placed in special devices called bottle holders. It is also possible to use a special bag on the bike frame. The most high-tech are bicycle lights with metal halogen lamps. Such lamps are more economical and give a higher luminous flux. But the cost of such bicycle lights reaches several hundred dollars.
Also in the device of bicycle lights, bright LEDs are used. Such bicycle lights have better efficiency indicators than halogen lamps. The duration of the glow of lamps with LEDs reaches several tens of hours when using one set of batteries. A bicycle lamp with one LED of one watt is equivalent in light performance to a two and a half watt halogen lamp. Currently, there are bicycle lights with several LEDs with a power of up to 5 W each, which in terms of illumination power surpass 20 W halogen lamps. Bicycle lights with these LEDs are powered by external batteries. A distinctive feature of LED lights is a bluish light, while most types of bicycle lights have a white-yellow light.
The design of the front and rear parking lights uses low-power LEDs that work continuously or, if necessary, in a blinking mode. They are powered by batteries that last up to one hundred hours. LED marker lights are brighter than conventional reflectors and provide a more efficient way for cyclists to travel safely on motorways. And yet. the choice is yours. Here are a few questions that may arise when choosing a rear light and, in principle, a front bicycle light
LED vs. incandescent lamp?
The advantages of an LED over an incandescent lamp:. It is not as easy to break as a lamp. In the lamp, light is emitted by a fragile spiral, which is enclosed in an equally fragile glass bulb. The LED, on the other hand, shines with a small area of a semiconductor on which a phosphor is applied. light-emitting paint. All of this is protected by a glass or silicone lens. it is more efficient than a lamp. The efficiency of modern high-power LEDs reaches 130 or more lumens per 1 Watt of power consumption. For comparison, the efficiency of incandescent lamps does not reach 30 lm / W. Due to this advantage, the LED flashlight will shine longer than the lamp from the same batteries. life time. For LEDs, it is usually at least 50,000 hours of continuous operation. For a lamp, 5000 hours is a very good indicator. In addition, the lifespan of the LED is not reduced, even with very frequent switching on and off. LED lights can have strobe, SOS and similar flashing signals, which are lacking lamp. sizes. LED flashlights can be very small. ease of focusing. LED light is distributed much more evenly than lamp light. The stain is smoother. allow you to adjust the brightness over a wide range. The brightness of the LED is controlled by the supply current. The higher the current, the higher the brightness. Each diode model has its own maximum allowable supply current. If this current is exceeded, the LED overheats, the service life is sharply reduced, the efficiency decreases.
Lumen is a unit of measure for light output. Without going into the essence of physical definitions, one lumen can be characterized as the light emitted from one wax candle, but not spreading in all directions, but collected in a beam of a certain shape. In the lantern world, there are two well-established concepts associated with lumens. Bulb lumen or lamp / diode lumens. This is the luminous flux coming directly from the lamp or diode without taking into account the losses in the optics. Torch lumen or lamp lumens. The luminous flux at the exit from the lantern already includes losses on the reflector, glass or lens. Different manufacturers may use different methods to indicate the luminous flux of their lamps. Some indicate bulb lumens, others. torch, manufacturers of cheap Chinese lamps such as Ultrafire, Aurora, etc. generally indicate the maximum luminous flux values available for a particular LED model, while overestimating the real luminous flux of the lantern by two or more times. On August 18, 2009, the ANSI / NEMA FL-1 standard was adopted, allowing more reliable comparison of the parameters of lamps. The standard covers the following indicators: emitted luminous flux, operating time, peak light intensity, light range, shock resistance and water resistance. The standard is currently used by manufacturers such as Maglite, Princeton Tec, Surefire, Petzl, Energizer, Streamlight, Black Diamond, Duracell, FenixLight and others.
Anodizing? What? What for?
Anodizing is a protective and / or decorative metal coating. Protects the body of the lantern from oxidation, does not conduct electric current, improves appearance. The anodized body of the flashlight is abrasion-resistant, but resists impacts on hard surfaces. On impact, the inner, relatively soft part of the body is punched out and a chip is formed. There are two types in lanterns: grade II and III. The higher the degree, the thicker and more durable the anodizing. Anodizing is applied electrochemically. The part is immersed in an acid solution and an electric current is passed through it. The thickness, hardness and color of anodizing depend on the temperature of the solution, the current density and additionally used dyes. Applicable for both aluminum and titanium lanterns.
Why do some flashlights have smooth glass, and some have a lens?
Lanterns can be reflex or lens. A reflector is a reflective bowl with an LED or lamp in the center. It collects light from source into a beam of a certain shape. Typically, the beam formed by the reflector looks like a bright central spot and a less bright area of side illumination. Such an optical system is protected from water and dust by a flat glass with a rubber gasket. A lens, or an entire lens system, also collects light into a beam. When using lenses, the beam can have a variety of shapes. From a uniform circle without a central bright spot to a narrow, almost laser beam without any side illumination at all. The focusing of a flashlight with a lens can be variable, that is, the same flashlight in different positions of the lens can shine well into the distance and illuminate evenly and conveniently near. The disadvantage of some variable focus flashlights is poor sealing. When immersed in water, liquid seeps inside, disrupting the operation of the electronics.
Reflector. Smooth or wrinkled to choose?
A smooth reflector (in English terminology. smooth) is used in long-range flashlights. The spot of light has a bright central spot and a sharp transition to the region of weak side illumination. At the same time, the diameter of the reflector is equally important for a real long-range flashlight. The larger it is, the better the focusing. One should not expect miracles of range from a flashlight with a smooth reflector 1 cm in diameter. The crumpled (Orange Peel) reflector has a rough structure, which smooths out the sharp transition from the central spot to the side illumination area. It is convenient to use such a flashlight at short distances. The light spot is obtained with a less bright center, but it is large. This is the kind of reflector you need for a bike light. Because it is more convenient to see a large, but not far away light spot
What does warm or cold LED mean??
LEDs can have different color temperatures. That is, the light of an LED can have shades from warm yellowish, like the usual incandescent light bulb, to cold, giving in to blue. Which diode to choose depends on the tasks that you set for yourself and individual perception. For outdoor use in summer, the choice of warm LED is preferred. Cold light appears to be brighter, but has poorer color rendition than warm light. This is especially true for shades of red and yellow. Green grass may appear gray in the light of a cold diode. For our purposes, it is better to take a cold one. We don’t care what color the grass will be on the street, do we? 🙂
Bicycle light: 6 comments
Now, I know how to choose a bike! Thank you =)
but what is the name of the lantern, as in the first picture?
Unfortunately, I can’t tell you.
detail in the human eye is in the yellow part of the spectrum, diodes with yellow are still not friendly, the author is incompetent in this matter “For our purposes, it is better to take cold”
The explanatory article is all popular and accessible.
How to choose a bike light and what to consider when buying?
The standard bike does not include lights or headlights, but the need for these devices is obvious. Moving in the dark without light, you can not only “catch a hole”, but also create an unforeseen situation on the road.
That is why we strongly recommend all cyclists to buy bicycle optics, especially since the range of these devices is quite wide and you can always choose a model at the best cost.
Bike lights versus bike lights: what’s the difference?
Until recently, bicycle headlights confidently occupied the leading position, but with the advent of bicycle lights, more and more cyclists are choosing the latter.
The main arguments in favor of lanterns are:
- Versatility: the device can be used not only to illuminate the road while cycling, but also as a hand lamp in all situations;
- Functionality: many models of flashlights can work in several modes, while a bicycle headlight. only in one;
- Compactness: flashlights work from built-in rechargeable batteries or batteries, and bicycle lights. from external batteries, which take up additional space.
Points to consider when choosing a bike light?
Since the range of bicycle optics is very wide and is represented by a variety of models in terms of characteristics and design, the choice of a flashlight can be quite difficult.
To make the right choice, you should focus on the following points:
- Light parameters
A good flashlight is not the one that is the brightest and most long-range, but the one in which these parameters are combined with a large angle of illumination. By illuminating a wide area, such a device allows you to better navigate while driving and notice obstacles earlier. Models with a textured reflector can be called a worthy option, as they provide a uniform luminous flux.
The range of the flashlight should be at least 50-100 meters, only in this case the optics will allow you to safely move at high speed. As for brightness, this parameter in lanterns is most often adjustable: depending on the level of illumination, you can set the backlight mode, medium and high brightness.
In bicycle optics, both “warm” and “cold” LEDs are installed, which, respectively, give a soft yellowish and bright white light. This parameter practically does not affect the quality of lighting, so this is a matter of taste.
- Batteries and their capacity
The lightest and most compact flashlights are LED with one battery: rechargeable or battery. Experienced cyclists carefully monitor the timeliness of recharging flashlights, but at the same time they always keep a replaceable battery in stock. The duration of the flashlight operation without recharging should be several hours so that it does not go out at the most inopportune time. On long trips, you can extend the life of the optics by selecting the economy mode.
- Design features and management
Because a bicycle light is often used in extreme conditions, its housing must be waterproof, shockproof, and impervious to both low and high temperatures. Management should allow you to switch modes in one motion, without being distracted from the road and without losing control of the steering wheel. As a rule, standard mounts are included in the package of flashlights that securely fix the optics.
Which bike light to choose: Chinese or branded?
Chinese bicycle optics are either their own developments of companies, or clones of models of popular brands. With decent quality, these products are distinguished by an affordable price. As for branded flashlights, for a higher price you will receive a higher build quality, extended functionality and warranty from the manufacturer.
If we also consider that almost all branded lamps are assembled in China, then it becomes not entirely clear why overpay 100, or even 200 for a trademark, without getting any technical advantage.
We hope that our tips on how to choose a bike light will help you get a quality and reliable bike optics.
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How to choose a bike light?
Which bike light to choose?
We will tell you how you can light your way, and how to choose a lamp for your bike.
In order to drive safely in the dark, you ideally need:
- headlight (lantern) so that you can see the road, and you can be seen by oncoming cars / cyclists / pedestrians;
- a taillight (flasher) so that those who follow you can see you;
- reflectors. for both.
And, if everything is more or less clear with reflectors and flashing lights, then the choice of a headlight (lantern) is not an easy matter. Let’s figure out what to look for when choosing.
Everything is clear here: the longer the flashlight / headlight works at maximum brightness, the less you need to worry that the battery will run out at the most crucial moment. The operating time ranges from 1.5 hours to 24 hours for particularly extreme night driving, and the cost of the device rises accordingly. You will have to pay for a particularly bright and uninterrupted light for several hours, in some cases more than 10000r. But if you use external batteries, it doesn’t cost anything to have multiple sets and replace them as needed.
Luminous flux and lighting range
If you are counting on driving in the dark and not only on white nights, then the flashlight should be such that you can drive as (or almost as) fast as during the day. Most often, the range of brightness is from 150 lumens to 1000 lumens, depending on the selected mode (maximum illumination, medium, energy saving). For a confident ride, it is better to take at least 360-400 lumens and with a lighting range of 30-40 meters.
Not only the brightness of the light is important, but also its temperature. It is better if the light is neutral white, without excessive yellowness or, on the contrary, blue. Too yellow light will be dim, and too blue light will lack contrast. With low contrast (especially at high speed), the road relief is poorly read, and this is uncomfortable and unsafe. A light temperature of 6500K or so is good.
Not only the brightness of the diodes is important, but also how they are located, and where, accordingly, the light flux is directed. For reliable illumination, you need a lantern with a powerful central beam of light that will pierce the darkness 30-40 meters ahead, and not evenly scattered light on the sides. On the other hand, it is good when the manufacturer also provides for peripheral lighting: on some lamps, symmetrically located light strips give side illumination, then visibility improves. If you choose a bicycle headlight online, look in the description for bimshots. photos of light spots of different lights.
Buy one expensive flashlight for life and take care of it or stay on the budget option, periodically buying a new one, because the flashlights get lost and break? The choice is yours! One high-quality flashlight will last a long time, it is environmentally friendly and economical, but keep in mind that the world does not stand still, new brighter diodes and smarter flashlights are constantly appearing in comparison with previous models.
What are the flashlights, and which bike lamp to choose
Universal handheld flashlight
It is so good that it is universal: you can carry it in your or backpack, use it not only when driving. The mount is purchased separately, from 400r. By the way, such a flashlight is attached not only to the steering wheel, but also to the helmet (the mounts are different), or you can make it cleverly and install two lights: both on the steering wheel and on the helmet.
- Lightweight, compact.
- Quickly put on and off, which means, leaving the bike, you take it with you, and it will stay with you longer, and not fall into the clutches of a thief.
- One battery will last for an hour and a half, maximum brightness, then you will have to change the battery.
- You can forget to take it with you, but it will come in handy
Headlights with internal battery
Have a built-in Li-Ion battery that you charge from USB.
- No need to delve into the topic of external batteries.
- No wires get in the way.
- If the battery is discharged, then it is discharged, and nothing can be done.
Headlights with external battery
This is exactly the option when you can stock up on batteries and change them, driving at least 12 hours on a polar night (well, suddenly?) For most headlights, 18650 Li-ion batteries are suitable (168A is the same). A block of four batteries provides from 2 to 3 hours of operation at maximum brightness of a headlight of 900-1000 lumens, that is, having two sets, you can not worry for 4-6 hours.
- Reliable if you don’t forget to recharge the batteries.
- You will also have to spend money on batteries (one set will cost from 2500-3000r).
- Wires are inevitable.
Rear light (dimension)
It can be on constantly, or it can blink: even the simplest modes are now in several modes. It is better to choose batteries / rechargeable batteries as bright as possible, and also quick-detachable for the reasons mentioned above: you should not be too lazy to take it with you when you leave your bike and go. And, if it’s not worth saving on the front lamp, then here the younger models start at 350r. We’ve covered the basic things to know when choosing a bike headlight, but it’s worth choosing based on the frequency of your night trips, riding speed and style, taste and budget. But let’s say one thing for sure: driving with headlights is much more pleasant and safer. Have a nice trip and take care of yourself!
Parts of LEDs
Epoxy body. epoxy Wire bond. thermocompression lead wire Die. crystalDie cup. crystal bowl wiring
LEDs come in all shapes and sizes, but 3mm T-1 and 5mm T-1¾ are the most common. Crystals. tiny semiconductor cubes whose composition determines the color of the light emitted. Located at the base of the crystal cup, which have reflective sides to reflect the light emitted from the end of the LED chips. The epoxy body is shaped to act as a lens and focus light into a beam. The distance from the crystal cup to the domed end of the lens determines how strongly the resulting beam of light is focused. Some LEDs have flat or even concave ends that focus the light into a wide beam.
LED colors. Visible LEDs
|more than 1100||Infrared|
|770-1100||Long wavelength near infrared (NIR)|
|770-700||Shortwave near infrared (NIR)|
LED colors are often indicated in nm (nanometers), which measures the wavelength of light. Wavelength specified. highest power wavelength. LEDs are not completely monochrome, but rather produce a wavelength over a short portion of the color spectrum. The diagram on the right shows the ratio of color to power in a standard green LED. the highest point. 565 nm, but it emits light in the range from 520 to 610 nm (meaning a portion of the spectrum). Half of the spectral line width. the width of this curve at 50 percent power (0.5 on the Y-axis). for this LED, it is about 30 nm. and also measure “purity” (monochromaticity) colors.
Pay attention to the temperature shown in the upper right corner of the graph. the LED produces slightly different colors at different temperatures. They also emit different colors at different amperages, especially white LEDs, which depend on how the phosphor changes the multicolored matrix to white.
The infrared band can be divided into Near Infrared (NIR) and Far Infrared (IR). Far infrared. Thermal infrared radiation tends to detect hot objects or see high temperature leaks in buildings, and paths outside the range of LEDs. (NIR can be further divided into two bands. longwave and shortwave based)
Infrared LEDs (LEDs) are sometimes called IREDs (Infrared LEDs).
Ultraviolet light is divided into three ranges: UV-A, which is fairly harmless; UV-B, which causes sunburn, and UV-C, which destroys things. Most of the ultraviolet B and C light from the sun is filtered by the ozone layer. we receive very little of this radiation. LEDs emit ultraviolet-A.
400 nanometers. fairly common wavelength for UV LEDs. It is located on the border between the violet and ultraviolet range, thus. a significant portion of the emitted light is visible. For this reason, 400nm UV LEDs are sometimes rated in millicandellas, even though half of their energy is invisible. LEDs with lower wavelengths, such as 380nm, are usually rated not in millicandellas, but in milliwatts.
Don’t look into UV LEDs!
White light. it is a mixture of all colors. Color temperature. a measure of the relative amounts of red or blue. higher, color temperatures have more blue.
Incandescent light bulb 15 W
Incandescent light bulb 60 W
Incandescent light bulb 100 W
Incandescent light bulb 500 W
500 watt krypton bulb
Industrial fog with smoke
Sun 30 ° above the horizon
Sun 50 ° above the horizon
Remember what it is. a measure of color, not brightness, so don’t be surprised because moonlight “hotter” than a carbon arc. It only means that the color is more blue and that’s it.
White LEDs have a color temperature, but Monochromatic LEDs do not.
The total power released as light is called radiant energy or radiant flux and is measured in watts. How bright an object is, however, will depend on two additional factors:
- how much emitted flux is released towards the observer
- how sensitive the observer is to the wavelength of light.
To quantify, first, we must introduce the concept of steradians (solid angle units), solid (3-D) angles. Think of a cone with apex at the source.
If the radiation flux of the radiation source is the same in all directions, the radiation intensity will be equal to the total radiation flux divided by 12.57 (4π) steradians, the spatial angle of the full sphere. In the case of an LED, the emitting flux is usually concentrated in the beam, and the radiation intensity will be equal to the emitting flux divided by the spatial angle of the beam. The width of the angles is usually indicated in degrees, and the radiation intensity is usually expressed in mW / sr., Which makes it necessary to convert the beam angle to steradians:
sr = 2 π (1.cos (θ / 2))
where sr is the solid angle, in steradians, and θ. this is the angle of the beam.
Luminous flux and luminous intensity. dimensions as radiant energy and radiation intensity, only corrected for the sensitive human eye. Radiation power at a wavelength of 555 nm, multiplied by a factor of 1, but higher light and lower wavelengths are boosted by lower factors, until infrared and ultraviolet wavelengths are reached when the radiation energy is multiplied by zero.
Luminous flux is measured in lumens, while luminous intensity is measured in lumens per steradian, also called candela.
The relationship between luminous flux, luminous intensity and beam angle means that by focusing on the LED in denser beams (decreasing beam angle), the luminous intensity (brightness) will increase without actually increasing the luminous flux (amount of light). Keep this in mind that when purchasing an LED for lighting purposes. a 2000 millicandel LED with a 30 ° viewing angle gives the same amount of light as an 8000 millicandel LED with a 15 ° viewing angle. (the angle is half the width and the height, so the beam is 4 times brighter). This is one of the reasons that ultra bright LEDs are often “purely aquatic”, to keep the light moving in one direction, rather than spreading in all places.
|The power of light||mcd|
The brightness of LEDs is measured in millicandels (mcd) or thousandth of a candela. LED indicator usually in the range of 50 mcd. “Ultra bright” LEDs can reach 15000 mcd and above.
In comparison, a typical 100 watt incandescent lamp produces approximately 1,700 lumens, if the light is emitted equally in all directions, it will have a brightness of about 135,000 mcd. If the beam is targeted at 20 °, then it will have a brightness of about 18,000,000 mcd.
The intensity of light and other electromagnetic radiation, as power per unit area, is measured in watts per square meter. Conventional incandescent bulbs emit more energy in the infrared than in the visible spectrum. The amount of light energy is called luminous flux and is measured in lumens and is defined as the amount of light emitted by 1/60 cm2 of the area of pure platinum at its melting point (about 1770 ° C) within a solid angle of 1 steradian. For example, in total, the radiation power (luminous flux) from a 40 W incandescent light bulb is about 500 lm, while the radiation power of a 40 W fluorescent tube is about 2300 lm.
Illumination intensity, similar to the intensity of electromagnetic radiation (which is the power per unit area). luminous flux per unit area is called illumination. The unit of illumination is lumens per square meter, also called lux:
1 lux = 1 lm / m² 1 lux = 1 lm / m²
The unit of luminous intensity is one lumen per steradian, also measured in candelas (cd):
1 cd = 1 lm / sr 1 cd = 1 lm / sr
LED Brightness. UV and Infrared LEDs
Since candela and lumens. units that are adapted to compensate for the variable sensitivity of the human eye to different wavelengths, and infrared and ultraviolet LEDs are completely invisible (by definition) to the human eye.
Infrared and UV LEDs are measured in watts for emitted flux and watts / steradians for emitted intensity. Quite typical “bright” an infrared LED produces approximately 27 mW / sr, although it can go up to 250 mW / sr or so. Signal LEDs, like on TV remotes, are much less powerful.
Keep in mind, however, that LEDs are not completely monochromatic. If their peak is close to the visible spectrum, then their bandwidth may overlap the visible spectrum enough to be visible as a dim cherry red light.
This dim red light, incidentally, is often mistakenly required to distinguish well-illuminating infrared diodes from dimmer infrared diodes. Which diode is best for a particular application depends entirely on the wavelength to which the receiver is most sensitive.
Typically, different colored LEDs require different voltages to operate. red takes the least voltage, and as the color pushes the color spectrum towards blue, so does the voltage requirement. Typically, red LEDs require about 2 volts and blue LEDs require about 4 volts. Typical LEDs, however, require 20-30mA of current regardless of voltage requirements. The graph on the left shows how much the amperage of a typical red LED will vary at different voltages.
Note that the LED below 1.7V is “off”. Between 1.7V and 1.95V “dynamic resistance”, the voltage-to-current ratio is reduced to 4 ohms. Above 1.95V the LED fully “switched on” and the dynamic resistance remains constant. Dynamic resistance is different from resistance in which the curve is not linear. Just remember that this non-linear relationship between voltage and current means Ohm’s law does not work for LEDs.
Formula to calculate the series value of the resistor:
Rseries = (V. Vf) / If
where Rseries is the value of the resistor in Ohms, V is the voltage, Vf is the voltage drop across the LED, and If. LED amperage to be seen.
For example, for the aforementioned diode, a voltage of 12 V at 500 ohms in a resistor would be good.
You can use one resistor to drive the current of a series of diodes, in which case Vf. this is the total voltage drop of all LEDs. It is not always a good idea to use one resistor to control a group of LEDs, if they use the same amperage, it can lead to different brightness or smoke.
Is a series of LEDs really necessary?
In a word, no. The series of resistors is not necessary if the Vf. Voltage can be adjusted according to the LEDs. One way to achieve this is with balanced LED batteries. If the LED voltage Vf is 1.2V, you can use a row of ten diodes (10 x 1.2V = 12V) with a 12V battery without a series of resistors.
However, you must be sure that the battery is capable of supporting the expected voltage, some batteries often supply slightly more voltage than rated (for example, a 12-volt car battery can reach 13.8 V when fully charged), but different types of batteries have different internal resistance. which leads to “skew” voltage under different load conditions.
Here is a small table showing typical internal resistances of different types of batteries. Notice how the AA alkaline battery has 5 times the internal resistance of the AA NiMH battery and the D alkaline battery 11 times the internal resistance of the D NiCad.
|AA Nickel-metal hydride||0.03|
|Note: Internal resistance in the table when the battery is fully charged and at room temperature.|
In addition, when the battery is discharged, the voltage will drop significantly. Due to the sudden change in voltage along the curve (see graph in the section “Using LEDs”) small voltage changes will lead to large changes in current.
Adding resistance to the circuit will help stabilize the voltage across the LED. In a sense, an LED and a resistor act in series as a voltage regulator.
In series with the resistor, the LED will reduce voltage throughout the circuit until it conducts. As soon as it starts to conduct, the resistance drops slightly. by only a few ohms. The voltage drop across the boost resistor and the voltage drop across the LED remains virtually corrected. The voltage drop across the LED remains slightly above the threshold voltage even if the supply voltage rises. Any further increase in supply voltage increases the voltage drop across the resistor but not across the LED.
See what happens when the voltage supplied by a 150 ohm resistor in series with the LED ranges from 4.5 to 5.5 volts.
You can see how the LED voltage (Vled) changes by only 0.03V, even if the voltage changes by 1V. Even with a small increase in LED voltage, the current increases by 6mA.
The LED in question has a Vthreshold of 1.9 V, above which it has a dynamic resistance (Rdynamic) of 4.55 ohms and turns on 20 mA at 2 V. (This is an example of the rear LED from “Using LEDs”). Supplied voltage is 5V and Rseries 150 ohm. Here are the formulas:
Ve = Vsupply. Vthreshold
I = Ve / (Rseries Rdynamic)
Vseries = Rseries / (Rseries Rdynamic) Ve
Vled = Vsupply. Vseries
Ve. voltage is above the threshold, I. current is currently in the circuit, Vseries is the voltage drop across the resistor, Vled is the voltage drop across the LED.
A situation in which it is really important to connect a diode without a series resistor. This is when you need maximum efficiency. The series resistor draws power (P = I2R). and variations in brightness may be tolerated.
There are also other ways to control the current with a diode. A voltage regulator can do a great job of this, but perhaps a current regulator like this is even better:
Diode controlled by a simple current regulator
LED movement with alternating current.
The first and most obvious question is why? But we’ll skip this, assuming you know the reason.
There are several factors to consider. Each of the LEDs only conducts for the time during that part of the positive half of the cycle during which the voltage is above the LED threshold voltage.
This means that the LED spends less than half the time that brightness produces. Second, even when the LED is conducting, the average voltage will be much less than the peak voltage. Average voltage of the positive half of the sinusoid. only 64% of the peak voltage. The brightness is therefore further reduced.
This is what I mean. X-axis is time, Y-axis is voltage. Blue line. supply voltage; Red line. LED threshold. In this case, the peak voltage. 5B, and a threshold. 1.2V (typical for red LED). “Effective voltage”(author’s term) is the voltage that is above the threshold voltage, the voltage that actually illuminates the LED; the rest of the voltage does nothing, either because it is below the threshold, or it is because it has the wrong polarity. The effective stress is indicated in the graph with gray areas. Light gray area. average effective voltage for AC supply voltage; here, 1.04 V. Dark gray area. the average effective voltage for a DC supply, 3.8 V, which will pass the AC current. Light gray area. only 27% of the area of both gray areas combined. If the LED had a threshold voltage of zero (which wouldn’t be good?) The effective AC voltage would still be only 32% of the effective DC voltage. As threshold voltage rises, ” duration of inclusion ” goes down from there.
Effective voltage (V. V t). term from the formula above and can replace it to calculate the value of the desired resistance.
It is possible to increase the effective AC voltage from the theoretical maximum of 32% of the effective DC voltage by increasing the supply voltage. this makes the voltage limit a smaller fraction of the highest voltage, so that the LED will cycle earlier and stay on longer. But you should avoid using a voltage limit greater than the reverse voltage that the LED can withstand, usually 5 volts. Remember that when the LED is not conducting, all voltage drops will pass through it. You can work around this problem by connecting another separate LED in the circuit. silicon diodes can withstand much higher reverse voltages than conventional LEDs, although additional diodes will introduce a second limiting voltage. Including a full-wave rectifier in the circuit will allow you to drive the LED in both halves of the cycle, increasing the maximum effective voltage to 64% of the DC voltage, but with two additional voltage limits.
Some white LEDs require further voltages (usually 3.5 or 4 volts) very close to their maximum reverse voltage (typically 5 volts), so that the LED will only be on for a very small part of the cycle, making it very weak. For example, a 3.5 volt diode connected to 5 volts AC will only have 0.25 volts effective voltage, 17% of 1.5 volts effective DC.
To compensate for the low effective voltage level, we want to drive the LED rather difficult to get an average current of up to 20mA. If the effective voltage is only 0.25 volts, then the resistor should be 13 ohms and the current peak current should be 120 mA. Can the LED handle 120mA peak current? Probably not.
One possible solution. these are two LEDs in reverse-parallel connection, one is polarized to light during the positive half of the cycle, and the other is polarized to light during the negative half of the cycle. Right off the bat, this doubles the light output as we are using both halves of the loop. In addition, since each diode has a reverse voltage, we will see a drop in the front voltage across the diode, you can control the voltage as you want, and the duty cycle can become 64% shorter. Using rectangular AC pulses instead of sinusoidal AC pulses will allow you to achieve nearly 100% either by using reverse parallel diodes or a single diode wired at twice the stroke for a half cycle.
Review of the 12 best bike lights
Cycling light is a necessary accessory for a bicycle, ensuring the safety of not only the cyclist, but also other road users.
Device and principle of operation
Main structural elements:
- source of power;
- Light source;
- optical system;
To prevent dust and moisture from getting inside, the design of the device provides for the presence of special rubber seals at the joints of parts and on the control elements.
Advantages of anodized aluminum housing
Anodizing is a special coating applied electrochemically to the metal surface. It protects the case from oxidation and exposure to negative atmospheric factors.
Anodized metal increases the strength of the product, thereby extending its life.
In the manufacture of the body of bicycle lights, aluminum with anodizing of II and III degrees is used. The latter is characterized by a greater thickness of the protective layer.
The optical system is designed to focus the light beam. There are two types of optics used in the design of bicycle lights.
The reflector is a reflective bowl with a light source in the center. Reflectors are protected by flat glass to prevent dust and water ingress.
Reflectors can be:
Smooth reflectors are characterized by a longer range of illumination, textured reflectors provide an even but slightly reduced light flux.
Lenses are designed to form light from source into a light beam, while the shape of the beam is characterized by a variety of shapes.
Depending on the lens, the light beam can appear as a uniform round spot without a clearly defined center or as a narrow beam without side illumination.
Purpose and functions
The purpose of a bicycle light depends on the type of accessory. Separate front and rear bike lights.
It has two functions:
- road lighting in front of the vehicle;
- side light.
Front Bike Light Requirements:
- the device must have sufficient illumination for a timely response and making the necessary maneuvers when the vehicle is moving at a speed of 25 kilometers per hour;
- the device must provide visibility of the roadway at a distance of 5 to 30 meters from the steering column.
They perform the function of marking a cyclist on the road for road users moving behind the vehicle. Taillight color. red.
A lighting device with a laser beam allows:
- increase the visibility of the vehicle on the road;
- improve the appearance of the bike.
Negative sides of the laser device:
- increased energy consumption;
- increased weight of the bicycle headlight;
- higher price.
The bicycle accessories market also offers rear dimensions with turn signals.
Such lighting devices indicate to road users moving behind the bike about the upcoming maneuvers of the cyclist and eliminate unnecessary manipulations (there is no need to indicate with your hands which direction the bike will turn).
Types of bicycle lights:
- helmet flashlight;
- dynamo lights;
- hand torches.
- high brightness;
- resistance to mechanical stress;
- long service life.
The design of halogen lighting fixtures is designed to create a directional light flux. A halogen light source is a flask filled with iodine or bromine vapor.
Halogen lights are not used as side lights, they do not flash. The products are characterized by bright light and fast energy consumption.
Flashlights on the helmet
The helmet-mounted lighting device makes it possible to direct the flow of light in the desired direction. The bicycle accessory is attached to the helmet using special straps.
The use of a helmet-mounted bicycle light does not excuse the vehicle’s headlights.
The lighting device operates from a dynamo generator or a hub dynamo. The light sources in dynamos are halogen lamps or LEDs with a stabilizer.
Dynamo lights are compact devices that are unpretentious in operation. The main advantage of this type of lighting fixtures is the absence of the need to purchase batteries.
Laser bike lights
The main task of the laser is to provide additional safety. The laser bike light emits two red stripes on either side of the vehicle.
The laser beams are not illuminated by the headlights of cars moving behind the bike, or by the light of street lamps. Most models of laser illuminators have multiple laser modes.
An LED hand-held flashlight can also be used as a front bike light. The advantages of the lighting device are:
- high mobility;
- ease of attachment.
Types of light sources for bicycle flashlights
There are several types of bicycle light sources on the bicycle accessories market:
- duty officers;
Duty lighting devices are designed for riding in the twilight time of the day and in cloudy weather. The illumination range of the pilot light is about five meters.
The light range of powerful models reaches from 130 to 150 meters, the bicycle accessory is suitable for moving outside the city, in unlit areas.
How to choose a bicycle flashlight
An important consideration when choosing a bicycle light is its purpose. When driving on city highways, you will need a bicycle headlight with a good side glow.
If you travel outside the city a lot, you will need a bicycle flashlight with a narrow beam to avoid dazzling other road users. In case of displaced movement, it is better to give preference to a lighting device with an adjustable operating mode.
Key selection parameters:
- light flow;
- scattering angle;
- illumination level;
- working hours.
Luminous flux. a parameter that determines the total amount of light produced by the lighting device, while the scattering of the luminous flux is not taken into account.
The unit of measurement of luminous flux (power) is lumen. A sufficient power of a bicycle flashlight is considered to be a range of 700-900 lumens.
The luminous flux emitted by the lighting fixture has a certain divergence angle. The wider the stream of light, the better. The luminous flux should be uniform, without a pronounced spot in the center. The scattering angle of the bicycle light must be at least 125 0.
Illumination level is an important parameter in choosing a lighting fixture. The indicator is measured in lux and is the ratio of the luminous flux power (measured in lumens) to the illuminated area (m 2).
A sufficient level of illumination for cycling is 15-20 lux.
The bike light creates three light zones:
- light area. represents a well-lit place;
- corona. transition zone between flux and diffused light;
- diffused light. an area with low illumination quality.
The water permeability of the bicycle accessory must meet the IPX standard. Leading manufacturers use the following markings to determine the degree of tightness of the device:
- IPx6. protection against strong water flows from any direction is provided;
- IPx7. the device can withstand short-term immersion under water to a depth of one meter;
- IPx8. the device is protected when fully immersed to a depth of more than one meter.
The LED bicycle light has a continuous working time of 10 to 12 hours, and the lamp accessories are designed for 3-4 hours.
- source of power;
- fastening method;
- number of operating modes;
- additional options.
The lighting device can be powered by:
- from nickel batteries (AA and AAA format);
- from a lithium-ion battery (18650/14500 format);
- portable battery.
Benefits of Nickel Batteries:
- light weight;
- long working time;
- low cost.
The disadvantages of nickel power supplies include:
- weak stream of light;
- fuzzy light spot;
- low illumination level.
Advantages of battery power supplies:
- distance of the light beam;
- good illumination;
- adjustment of the level of brightness of the bicycle light;
- powerful luminous flux.
Negative sides of batteries:
- heavy weight;
- short period of work in maximum mode;
- high price.
LED lamps are characterized by a different color spectrum. from warm yellow to cold bluish. A cold diode is brighter than a warm LED, but inferior to the latter in terms of color rendering.
There are several ways to attach the light to the bike:
- articulated holder;
- clothespin clip.
Bicycle Light Holders Material:
The following types of mounts are distinguished:
Elastic fasteners are used to fix the auxiliary and side lights. The mount is a silicone or rubber strap.
The mounting brackets are designed as a bracket. The main advantage is reliable fixation of the lighting device.
- some difficulty in installing the mount;
- difficult to replace fasteners in case of failure.
Removable fastening is a compromise solution between mounting and elastic fastening.
It is made in the form of a half-cylinder and is rigidly attached to the bicycle, while the installation and removal of the light source itself can be performed without problems at any time.
Body-worn fastening allows you to fix the lighting device on the cyclist’s outfit, it is made in the form of Velcro or sets of ties.
Number of operating modes
There are single-mode and multi-mode lighting devices on the bicycle accessory market. Single-mode devices provide on-off function.
Operating modes can be fixed or programmable. The choice of types and number of modes depends on personal preference. What a good bike flashlight should be:
The best light source for a bike is an LED torch. LED products are characterized by the following advantages:
- shaking resistance;
- impact resistance;
- waterproof qualities;
- Ease of Management;
- bright radiation spectrum;
- efficient energy consumption.
The best product should have the following features:
- switching high and low beam;
- side lights;
- remote button for switching operating modes;
- automatic overcharge protection;
- removable mount.
The ideal bicycle light is a compact lighting device with dimensions no more than 120x25x24 mm, with a waterproof housing made of aircraft-grade aluminum with third-degree anodizing.
With shallow textured reflector, 18650 battery as power source, 500 lumen light output and five modes of operation (three brightness modes, strobe and SOS).
Rating of the best models in the categories:
- the most compact. bicycle lamp UniqueFire A10-B XM-L, country of origin China;
- the most powerful. UltraFire WF-800L bicycle light, country of origin China;
- the most popular medium-power bicycle light. FTT ZR-23 Original made in Japan;
- the best quality / practicality ratio. Chinese made Magicshine MJ-808 bicycle flashlight.
Best Front Bicycle Light
D.Light 12476 CG-120W for a bicycle with a handlebar attachment made in Taiwan, providing a good view in the dark. The headlight can be easily attached to the steering wheel without the use of any tools.
An attractive cost along with good quality is a strong argument in favor of the lighting fixture. Characteristics:
- power source. AA battery;
- the number of feeding elements. 2;
- number of light sources. 3 LED-LEDs;
- number of operating modes. three (far, near, flashing);
- operating time depending on the mode. from 30 to 120 hours;
- body material. plastic;
- weight. 0.27 kg.
- waterproof case;
- compact dimensions;
- universal removable mount;
- attractive design;
- backlit power button;
- affordable cost.
Best rear bicycle light
Magicshine MJ-818 from the famous Chinese brand Magicshine. The product delivery set includes:
- battery in a case;
- charger operating from a 220V network;
- mount (two rubber rings).
- power. 85 lumens;
- power source. battery pack;
- the number of power elements. 4 Li-ion 18650 batteries;
- number of light sources. 10 diodes;
- the number of operating modes. three;
- range of a light beam. 100 meters;
- operating time (when all lamps are turned on). up to 10 hours;
- switch type. ring dimmer;
- body material. aluminum;
- weight. 0.087 kg.
- shockproof housing with a high degree of protection;
- tempered glass optical lens;
- red intensity indicator;
- waterproof IPX-65;
- quick release mount.
The best bike light with turn signals
Nanoled PRO-L73 is a side marker bike light with remote control turning indicators.
Country of origin. China. The size is equipped with 16 LEDs (6 red LEDs. side light, 10 yellow LEDs. turn signals), as well as two lasers.
- power source. AAA nickel batteries;
- number of power supplies. 2;
- light source. LEDs;
- the number of operating modes of the brake light. three;
- scattering angle. 270 0;
- body material. plastic;
- weight. 0.15 kg.
- moisture resistant housing with IP64 protection degree;
- control panel with operation indication;
- fastener with seal.
Best cordless bike flashlight
Sigma Sport Buster 100 is a powerful compact rechargeable bicycle light from a Chinese manufacturer. Package includes USB cable and handlebar mount.
A renowned manufacturer has equipped the bike light with a one-piece LED system that emits a light beam with a sharply focused center and wide lighting angles.
The attachment to the handlebars is presented as a standard rubber strap, the diameter of the attachment is adjusted using the holes on the strap. Characteristics:
- power. up to 120 lumens;
- beam distance. 35 meters;
- power supply. built-in Li-ion battery;
- number of operating modes. six (standard, powerful, energy saving, strobe, flashing, SOS);
- operating time depending on the mode. from 2 to 10 hours;
- power supply. LED;
- body material. plastic;
- weight. 0.062 kg.
- powerful luminous flux;
- rugged waterproof case with IPX7 standard;
- convenient attachment to the steering wheel;
- charge capacity indicator.
Best bike light without batteries
Fenix BC3UR is a unique dual beam focusing bike light with built-in battery.
The bike light does not require batteries to operate, the device is charged via the micro-USB cable included in the package, or via an AC adapter.
A feature of the model is the presence of an electronic board, which displays information about the amount of energy of the built-in battery.
Characterized by powerful bright light, compatible with almost any model of bicycles, mounts on the steering column of a vehicle.
The manufacturer of the model is the Chinese brand Fenix, well-known in the lighting market. The developers used aviation aluminum with a protective coating, thanks to which the device case acquired unique moisture-proof properties and high strength. Characteristics:
- power supply. built-in 5200 mAh battery;
- light source. LED lamps Cree XM-L2 T6;
- the number of light sources. 2;
- distance of the light beam. 155 meters;
- light beam brightness. up to 1600 lumens;
- the number of operating modes. six (Burst. 1600 lumens, maximum. 800 lumens and medium. 500 lumens, minimum. 200 lumens, eco-mode. 100 lumens and flash mode. 200 lumens);
- time of continuous work. 20.2 hours;
- body material. aircraft aluminum with anodizing;
- weight. 0.222 kg.
- shockproof waterproof case;
- moisture resistance class. IPX6;
- OLED display;
- brightness control;
- overheat protection;
- convenient fastening system.
Best Proximity Cycling Light
MAGNIC Light is a non-contact bike light that was invented by the American scientist Dean Strothman. The first wonder lantern hit the market in 2012.
After some time, an improved version of the MAGNIC Light IC appeared, the main difference from the previous series is the presence of a microprocessor and an internal device that provides a bicycle flashlight glow when the vehicle stops. Characteristics:
- power. 150 lumens (at a bicycle speed of 25 k / h);
- weight. 0.06 kg.
- simplicity of design;
- compact dimensions;
Best halogen bike light
When creating the Sport Ellipsoid bike light, the innovative OPTAFLUX system was used, which increased the light output by 30%. Country of origin. Germany. Characteristics:
- power source. AA battery;
- the number of feeding elements. 5;
- light source. halogen lamp;
- range of a light beam. 60 meters;
- body material. plastic;
- number of operating modes. one;
- luminous flux. 12 lux;
- working time. 2.5-3 hours;
- weight. 0.120 kg.
- recharging connector built into the case;
- ease of use;
- moisture protection;
- charge indicator;
- snap-on convenient mount;
- long service life;
- attractive price.
Best Generator Bike Flashlight
AN LUN 10Lux is designed for a 6 volt bicycle generator. The fixing point of the luminaire is on the plug, the method of fixing is bolted.
- power source. 6 V generator;
- light source. LED;
- number of operating modes. one;
- luminous flux. 10 lux;
- country of origin. China.
- high mobility;
- compact dimensions;
- does not require power supplies;
- affordable cost.
Best Dynamo bicycle flashlight
The iLumenox VEGA 6V DYNAMO does not require batteries and accumulators, the device works by means of induction currents generated by the rotation of the bicycle wheels.
Powerful LED and reflective system increase light output for good illumination.
- power source. dynamo;
- power supply element. 6 V;
- luminous flux. 35 lux;
- beam distance. 10 meters;
- body material. aluminum;
- weight. 0.072 kg;
- country of origin. Taiwan.
- additional textured reflector;
- moisture-proof housing;
- modern design;
- electronic stabilization of luminous flux.
Best laser bike light
Stylish and compact Cmeilan X5 with laser illumination and direction indicators. Designed to be mounted on the rear of the bike. Bright LED lights allow you to spot your bike on the road in all weather conditions.
The lighting device is designed for operation in a wide temperature range from 20 to 60 0 С.
- distance of the main light beam. 40 meters;
- laser beam range. 5 meters;
- power source. rechargeable battery;
- power supply capacity. 2200 mA per hour;
- operating time in continuous flashing mode. 8 hours, in glow mode. 4 hours;
- operating modes. three (constant, emergency flashing, cross-flush);
- light sources. SMT LEDs;
- number of light sources. 29;
- body material. ABS plastic;
- weight. 0.248 kg.
- high brightness;
- built-in light sensor;
- automatic activation when boarding a vehicle;
- durable waterproof case;
- the presence of direction indicators;
- remote control;
- waterproof to IPX4 standard.
Best solar powered bike light
Economical Xingcheng XC-990. solar powered. Country of origin. China. The Xingcheng brand has been present in the bicycle accessories market since 1986, and its products are recognized all over the world.
Designed for mounting on the steering wheel of a vehicle. The body of the product is made of durable plastic, in the upper part there are control buttons (on / off).
- power source. solar battery, built-in battery;
- light source. LED lamps;
- the number of sources is four;
- body material. plastic;
- number of operating modes. two (constant light, blinking);
- time of continuous work. 9 hours;
- weight. 0.150 kg.
- the ability to recharge from a USB 2.0 port;
- convenient location of control buttons;
- financial savings on the purchase of batteries.
Best helmet bike flashlight
The popularity of the Fenix HP10 Cree XR-E LED Premium Q5 is due to its design features.
The efficient operation of the lighting fixture is ensured by a powerful LED lamp, the duration of continuous operation of which reaches about five years.
- power. 250 lumens;
- range of a light beam. 120 meters;
- power source. AA battery;
- the number of feeding elements. 4;
- number of light sources. LED with reflector;
- maximum operating time. 210 hours;
- the number of operating modes. seven (four brightness modes, three additional. duty blinking, stroboscope, SOS);
- body material. anodized duralumin;
- weight. 0.117 kg;
- country of origin China.
- dust and waterproof housing with IPX-8 protection degree;
- compact dimensions;
- high strength;
- reliable forehead mount;
- mode memory function;
- textured reflector;
- optical lens made of tempered heat-resistant glass;
- software with LED overheat protection;
- the ability to change the angle of inclination up to 90%.
The Fenix HP10 bicycle light attachment system ensures even distribution of the load on the head and cervical vertebrae, without causing any discomfort.