Test bicycle lights Fenix BT-10
I present to your attention a review of the bicycle headlamp Fenix BT-10 and at the same time “An introduction to lighting for dummies”. Superficially reviewed the basic things about LED lamps. I am repelled from the basic knowledge of the current-voltage. There will be little specifics - add. I consider the questions “Which lantern is better” in advance to be provocative
Unfortunately, I can not start this review with anboxing - I received the device for testing in a bag and with traces of operation. Batteries included too. All the light in the household is powered by 18650 lithium cells, and the headlamp requires 4 AA cells. Declared support for both disposable batteries and NiMH / NiCd batteries.
Why develop special bicycle lights at all? Is it possible to do with a simple flashlight? After all, they are now quite powerful.
It is possible, but a specialized device will do its job better. The topic of proper cycling is very holivornoy in the appropriate environment. In short, the light for active driving (we will not consider the dimensions of the front-view lamps to indicate ourselves on the illuminated city bike path) should give a bright spot a few meters in front of the wheel and strong side illumination so that you can see where to turn in a turn. In civilized countries, blinding of oncoming drivers is normalized. Everything is simple with us, but to direct a noticeable part of the world past the road is very wasteful. Tightness - by itself. Rain happens when it is not expected. Lifetime - a few hours on one set of batteries. 2-3 sets should be enough for the night of use, even if not at maximum mode. Bicycle flashlight is in a more favorable thermal mode compared to a hand lamp, because it is blown by a head wind. When the diode overheats, the silicone lens becomes cloudy in a few months, or it burns itself in clinical cases. Mount on the steering wheel should be reliable and convenient, so that you can quickly remove, but the headlight itself did not fall off and did not slip away. It is desirable to have a mount on the head or helmet. With good headlamps in Chinese stores tension.
')
Lights and lights can be roughly divided into weight categories for power consumption. These are 1W (3V, 300mA), 3W (3V, 1A), 10W (3V, 3A or 7V, 1.5A), a superweight with power supply from lithium-ion assemblies. How much light is needed is a moot point. A lot of it does not happen, but with an excess you can not budge a suitcase with power sources. The author uses two three watts with a different beam shape, but 2x10 W variants are also quite popular. The average lamp is powered by a single 18650 lithium-ion battery with a voltage of 3 to 4.2 V, a capacity of 2-2.5 Ah and a discharge current of 1-1.5 A. As can be seen, it will not be able to use 10W without loss of efficiency and resource. Three-watt diode it can feed up to three hours, one watt - about 10 hours. There are always weaker modes in the lantern. They are provided by PWM modulated current per diode. Usually it turns out 20% and 50% of the maximum power consumption. The operation time increases accordingly, and the efficiency of the diode itself in this mode increases markedly compared with the maximum allowable current.
What does a flashlight consist of? From optics, diode, housing, driver, power and switch.
Optics. Its task is to take the light from the diode and send it to the right place (on the road), and where it is not necessary to go - not to send (to the eyes of the oncoming driver and to the sky). At the same time there should be less losses. The main types of optics are reflector, ordinary lens and Fresnel lens. The Chinese mainly stamp the reflector, the lenses go to the lights with an adjustable beam shape, fresnel is used many times less.
Reflector
Lens
Fresnel lens
The LED in the bicycle world holds somewhere around 99.5% of the market. Halogen headlights almost disappeared from the scene, xenon did not come at her for several reasons. The problem is that manufacturers have failed to recalculate optics after replacing a halogen lamp with an LED. The spiral lamp shines in all directions, and the diode - a cone forward. The diode requires that it be fed with a fixed or at least not exceeding the limiting current. He shines and heats up very sensitively.
Typical diode. This is the XP-G R5, which is similar and is used in this lantern. The diameter of the substrate is around 15 mm, it is aluminum for a better heat sink. Crystal - yellow, it is closed with a silicone lens-drop.
The case not only holds all the other parts together, but also serves as a heat sink. Brass radiators and thermal greases are used very widely.
The driver must apply the same direct current to the diode. If you simply connect the diode to the battery, you will actually get a short circuit and death with a firework of both the diode and in clinical cases of the battery itself. I do not consider the current limit through the diode by connecting a resistor in series, because the last century and low efficiency. Also, the driver provides mode switching and indication of low battery. Usually, some kind of DC voltage converter is used, or just a current source chip plus PWM on the controller. The first option provides constant luminosity, but can kill the battery by overdischarge. The second has higher efficiency, but a non-constant brightness. In general, driver efficiency is around 90%.
Typical connection scheme. Many options, but it is the most massive
Food - see above. For small lamps, this is 1 piece 18650 or less often two CR123 halves connected in series. They give the same discharge current, but twice the voltage and half the capacity. For large lamps go 2h18650, also consistently. Parallel connection is almost never used. For more power, there are portable power boxes connected to the headlight itself with thick copper wire.
18650 on the background of a finger-type battery, it is AA
The switch is usually connected to the gap between the driver and battery minus. So he must pass current amps through him without burning the contacts under the conditions of an actual vibrator. He also switches modes with a short press.
And now let's move on to the review itself. It is sad that there is no documentation or even an advertising booklet on the headlamp, and it’s scary to climb inside.
Contents of delivery. Rubber ring for mounting the headlamp on the steering wheel, waist or frame cover for the power supply unit, extension cable, mount on the head and the lamp itself.
Offal power supply. Soldering is rarely foul, the flux is not washed off. In the lid boost converter at 8.4V. It does not turn off and runs at idle even when the headlight is turned off, but there may be some kind of energy-saving circuit that is invisible to me. The boost to 8.4V was made explicitly for unification with lithium power, because the voltage exactly corresponds to the voltage of two fully charged lithium cans. The packaged batteries that were there when I got the headlamp for a test were burned out before the polarity was reversed. I did not choke on 4xNiZn with a total voltage of 7.6V. Standard round connector, waterproof. Not bathed, but it looks solid and opens with a funny sound "chpok." Old NiMH batteries did not start at maximum mode and heated wildly even at a weak one. I am writing this off as a great internal resistance. I could not crawl with an ammeter, but we can expect about 2 hours of work at maximum mode from fresh batteries with a capacity of 2000 mAh.
Radiator rear. Not just for furniture, it really works and heats up. The headlight itself seems plastic. Button on top, highlighted. Green when working and red when discharging. Mount on the steering wheel is quite adequate and should not be loose.
The simplest reflector with stripes. In the depths of the diode, most likely XP-G R5 or equivalent.
Helmet mount separately
And all in the collection. Inconvenient, because the headlight with a hot radiator rests on the head. Belts are too short and only reach to the ears. Although it may be a test sample bug. The helmet should fit normally
And now the bimshots. Filmed on antique Canon 300D, shutter speed 1/10, aperture 3.5, 18mm, ISO3200
The most complete
Average
And economy mode
The strange shape of the beam. The bottom spot is due to the reflection of light from the visor above the glass and scattering on those three stripes.
And for comparison, the Chinese on the XP-G R5. The diode works at the limit and gets 1.05A, but it is impossible to drive with such a lantern - very weak lateral illumination. Although the high beam in a couple to something with a wide spot will fit perfectly
Unfortunately, I can not start this review with anboxing - I received the device for testing in a bag and with traces of operation. Batteries included too. All the light in the household is powered by 18650 lithium cells, and the headlamp requires 4 AA cells. Declared support for both disposable batteries and NiMH / NiCd batteries.
Why develop special bicycle lights at all? Is it possible to do with a simple flashlight? After all, they are now quite powerful.
It is possible, but a specialized device will do its job better. The topic of proper cycling is very holivornoy in the appropriate environment. In short, the light for active driving (we will not consider the dimensions of the front-view lamps to indicate ourselves on the illuminated city bike path) should give a bright spot a few meters in front of the wheel and strong side illumination so that you can see where to turn in a turn. In civilized countries, blinding of oncoming drivers is normalized. Everything is simple with us, but to direct a noticeable part of the world past the road is very wasteful. Tightness - by itself. Rain happens when it is not expected. Lifetime - a few hours on one set of batteries. 2-3 sets should be enough for the night of use, even if not at maximum mode. Bicycle flashlight is in a more favorable thermal mode compared to a hand lamp, because it is blown by a head wind. When the diode overheats, the silicone lens becomes cloudy in a few months, or it burns itself in clinical cases. Mount on the steering wheel should be reliable and convenient, so that you can quickly remove, but the headlight itself did not fall off and did not slip away. It is desirable to have a mount on the head or helmet. With good headlamps in Chinese stores tension.
')
Lights and lights can be roughly divided into weight categories for power consumption. These are 1W (3V, 300mA), 3W (3V, 1A), 10W (3V, 3A or 7V, 1.5A), a superweight with power supply from lithium-ion assemblies. How much light is needed is a moot point. A lot of it does not happen, but with an excess you can not budge a suitcase with power sources. The author uses two three watts with a different beam shape, but 2x10 W variants are also quite popular. The average lamp is powered by a single 18650 lithium-ion battery with a voltage of 3 to 4.2 V, a capacity of 2-2.5 Ah and a discharge current of 1-1.5 A. As can be seen, it will not be able to use 10W without loss of efficiency and resource. Three-watt diode it can feed up to three hours, one watt - about 10 hours. There are always weaker modes in the lantern. They are provided by PWM modulated current per diode. Usually it turns out 20% and 50% of the maximum power consumption. The operation time increases accordingly, and the efficiency of the diode itself in this mode increases markedly compared with the maximum allowable current.
What does a flashlight consist of? From optics, diode, housing, driver, power and switch.
Optics. Its task is to take the light from the diode and send it to the right place (on the road), and where it is not necessary to go - not to send (to the eyes of the oncoming driver and to the sky). At the same time there should be less losses. The main types of optics are reflector, ordinary lens and Fresnel lens. The Chinese mainly stamp the reflector, the lenses go to the lights with an adjustable beam shape, fresnel is used many times less.
Reflector
Lens
Fresnel lens
The LED in the bicycle world holds somewhere around 99.5% of the market. Halogen headlights almost disappeared from the scene, xenon did not come at her for several reasons. The problem is that manufacturers have failed to recalculate optics after replacing a halogen lamp with an LED. The spiral lamp shines in all directions, and the diode - a cone forward. The diode requires that it be fed with a fixed or at least not exceeding the limiting current. He shines and heats up very sensitively.
Typical diode. This is the XP-G R5, which is similar and is used in this lantern. The diameter of the substrate is around 15 mm, it is aluminum for a better heat sink. Crystal - yellow, it is closed with a silicone lens-drop.
The case not only holds all the other parts together, but also serves as a heat sink. Brass radiators and thermal greases are used very widely.
The driver must apply the same direct current to the diode. If you simply connect the diode to the battery, you will actually get a short circuit and death with a firework of both the diode and in clinical cases of the battery itself. I do not consider the current limit through the diode by connecting a resistor in series, because the last century and low efficiency. Also, the driver provides mode switching and indication of low battery. Usually, some kind of DC voltage converter is used, or just a current source chip plus PWM on the controller. The first option provides constant luminosity, but can kill the battery by overdischarge. The second has higher efficiency, but a non-constant brightness. In general, driver efficiency is around 90%.
Typical connection scheme. Many options, but it is the most massive
Food - see above. For small lamps, this is 1 piece 18650 or less often two CR123 halves connected in series. They give the same discharge current, but twice the voltage and half the capacity. For large lamps go 2h18650, also consistently. Parallel connection is almost never used. For more power, there are portable power boxes connected to the headlight itself with thick copper wire.
18650 on the background of a finger-type battery, it is AA
The switch is usually connected to the gap between the driver and battery minus. So he must pass current amps through him without burning the contacts under the conditions of an actual vibrator. He also switches modes with a short press.
And now let's move on to the review itself. It is sad that there is no documentation or even an advertising booklet on the headlamp, and it’s scary to climb inside.
Contents of delivery. Rubber ring for mounting the headlamp on the steering wheel, waist or frame cover for the power supply unit, extension cable, mount on the head and the lamp itself.
Offal power supply. Soldering is rarely foul, the flux is not washed off. In the lid boost converter at 8.4V. It does not turn off and runs at idle even when the headlight is turned off, but there may be some kind of energy-saving circuit that is invisible to me. The boost to 8.4V was made explicitly for unification with lithium power, because the voltage exactly corresponds to the voltage of two fully charged lithium cans. The packaged batteries that were there when I got the headlamp for a test were burned out before the polarity was reversed. I did not choke on 4xNiZn with a total voltage of 7.6V. Standard round connector, waterproof. Not bathed, but it looks solid and opens with a funny sound "chpok." Old NiMH batteries did not start at maximum mode and heated wildly even at a weak one. I am writing this off as a great internal resistance. I could not crawl with an ammeter, but we can expect about 2 hours of work at maximum mode from fresh batteries with a capacity of 2000 mAh.
Radiator rear. Not just for furniture, it really works and heats up. The headlight itself seems plastic. Button on top, highlighted. Green when working and red when discharging. Mount on the steering wheel is quite adequate and should not be loose.
The simplest reflector with stripes. In the depths of the diode, most likely XP-G R5 or equivalent.
Helmet mount separately
And all in the collection. Inconvenient, because the headlight with a hot radiator rests on the head. Belts are too short and only reach to the ears. Although it may be a test sample bug. The helmet should fit normally
And now the bimshots. Filmed on antique Canon 300D, shutter speed 1/10, aperture 3.5, 18mm, ISO3200
The most complete
Average
And economy mode
The strange shape of the beam. The bottom spot is due to the reflection of light from the visor above the glass and scattering on those three stripes.
And for comparison, the Chinese on the XP-G R5. The diode works at the limit and gets 1.05A, but it is impossible to drive with such a lantern - very weak lateral illumination. Although the high beam in a couple to something with a wide spot will fit perfectly
Source: https://habr.com/ru/post/155489/
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