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Bora XM-L2 technical dive light

 

Delivering breakthrough lumen output and efficacy in the XM package, the XLamp® XM-L2 LED is the highest-performing, commercially-available, single-die LED. Built on the SC³ Technology Platform, the Xlamp XM-L2 LED delivers up to 20% more lumens and lumens-per-watt and double the lumens-per-dollar of the original XM-L. The XM-L2 LED offers the unique combination of high efficacy and high lumen output at high drive currents.

        • Max. power 10 W
        • Max. light output 1198 lm
        • Color temperature 6500 K
        • High quality TIR optics
        • FWHM 4,9°

    • Aerospace grade anodized aluminium light head that optimizes head dissipation and protecting LED electronics and optics
    • Constant current LED driver
        • 3 modes
          • 25% pwm
          • 50% pwm
          • 100% pwm
    • Piezo switch
        • Solid stainless steel body
        • Sealed to IP69K
        • Easy to clean metal surface
        • Long life (million cycles)

    • Adjustable laser cutted stainless steel goodman handle
    • Nickel plated IP69K rated brass cable glands

    • Aerospace grade anodized solid aluminium canister body and lid
    • 11,1 V 14000 mAh Li-ion battery pack with integrated BMS system
    • Dual o-ring protection
    • Gold plated banana plugs
    • Stainless steel Nielsen latch

    • Sealed battery compartment with pressure release valve

    • Every light is tested at 20 bar (~200 meter) for 60 minutes

    • With drysuit heating port

Mistral XM-L2 optical performance

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Optional drysuit heating port

All divelights optionally can have an additional port for heated undersuits.

Main features:

  • Illuminated piezo switch
    • Solid stainless steel body
    • Sealed to IP69K
    • Easy to clean metal surface
    • Long life (million cycles)
  • Power control
    • 25% pwm
    • 50% pwm
    • 100% pwm
  • e/o cord and blind plug with locking sleeve
  • The illuminated piezo switch indicates the output power of the heating system
    • blind – OFF
    • slow flashing – 25%
    • fast flashing – 50%
    • solid – 100%
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Mistral XHP-50.2 technical dive light

Mistral XHP-50.2

The XLamp XHP50.2 LED is the next generation of Extreme High Power LEDs that delivers the lowest system cost through the best lumen density, reliability and color consistency. Built on Cree’s latest high-power LED technology, the XHP50.2 LED improves the lumen density, voltage characteristics, reliability and optical performance of the XHP50 LED in the same 5.0 mm x 5.0 mm footprint. The new XHP50.2 LED provides an easy drop-in upgrade to achieve higher system LPW for lighting manufacturers with existing XHP50 designs, eliminating redesign costs. Its unparalleled lumen density and longer lifetime at higher operating temperatures also enables new and innovative lighting designs at lower system costs.

  • Max. power 18 W
  • Max. light output 1955 lm
  • Color temperature 5000 K
  • High quality TIR optics
  • FWHM 4,9°
  • Aerospace grade anodized aluminium light head that optimizes head dissipation and protecting LED electronics and optics
  • Constant current LED driver
    • 3 modes
      • 25% pwm
      • 50% pwm
      • 100% pwm
  • Piezo switch
    • Solid stainless steel body
    • Sealed to IP69K
    • Easy to clean metal surface
    • Long life (million cycles)
  • Adjustable laser cutted stainless steel goodman handle
  • Nickel plated IP69K rated brass cable glands
  • Aerospace grade anodized solid aluminium canister body and lid
  • 11,1 V 10500 mAh Li-ion battery pack with integrated BMS system
  • Dual o-ring protection
  • Gold plated banana plugs
  • Stainless steel Nielsen latch
  • Sealed battery compartment with pressure release valve
  • Every light is tested at 20 bar (~200 meter) for 60 minutes

Drysuit heating port (optional)

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What is colour temperature?

The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of a color comparable to that of the light source.

When the ideal black-body radiator is heated, the color of light it emits will change. This color begins as red in appearance and graduates to orange, yellow, white, and then blue-white to deeper colors of blue. The temperature of this metal is a physical measure in degrees Kelvin or absolute temperature. While lamps other than incandescent such as LEDs do not exactly mimic the output of this piece of ideal black-body radiator, we utilize the correlated color temperature (or Kelvins) to describe the appearance of that light source as it relates to the appearance of  a black body radiator.

Light is often referred to having a certain color temperature. Strangely, warm light is a lower color temp, and cool light, blue, is a higher color temp.

Here are some temps of some common light sources:

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LED driver technology

Direct Drive (DD)

Direct drive (DD) is the simplest and cheapest design. It is a direct path from the battery to the LED.

Sometimes there is a CPU and transistor to create different modes (25%, 50%, 100% …. etc.).

It is used when we want to make very powerful flashlights.

Advantages:

  • Cheap.
  • There is no flickering, so it is ideal for a video light.

Disadvantages:

  • Current is varying greatly with battery voltage. So the LED is dimming.
  • If there is a current limiter resistor, the efficiency is low (lower than a linear driver).
  • Voltage of the battery must be a bit higher than the LED voltage (generally ~3V) but not too much above. Othervise you can’t use this type of driver.

 

Linear Driver (LD)

This is the same as DD but with a “smart” resistor to limit current.

In this case the resistor value is not constant, it is continously adjusted by a linear regulator to make the current constant.

Most drivers use 7135 linear regulators (0.35A per piece).

Efficiency is varying with the battery voltage. The resistor burns off the extra power!

Eff.=Vled/Vbattery

Fully charged battery  Eff.=3.3V/4.2V=78%

Half charged: Eff.=3.3V/3.5V=94%

Discharged: Eff.=3.3V/3.3V =100%

When the battery voltage drops below Vled, the led starts dimming.

What happens if we use more batteries in series? The efficiency drops rapidly as more power wasted on the driver.

Advantages:

  • Simple and cheap design.
  • Constant current for most of the discharge of the battery.
  • There is no flickering, so it is ideal for a video light.

Disadvantages:

  • Voltage of the battery must be a bit higher than the LED voltage (generally ~3V) but not too much above. Otherwise you can’t use this type of driver.

 

Buck Driver

This is a more complicated design, also called as step down driver. It uses an inductor and capacitor to step down the battery voltage.Compared to a linear driver, the efficiency is more or less constant regardless of the battery voltage, which can be much higher than the LED voltage. The efficiency is between 70% and 90%.

An example would be using 4 li-ion batteries in series (16.8V ffully charged) to drive  3 series connect LEDs with a total Vf of around 13.2V. A buck driver will draw lower current from the input than what it will provide at the output. As the battery voltage drops, the buck driver will draw more current, but never more than the output current.

Advantages:

  • Can be used with battery packs that have a much higher voltage than the LED voltage.
  • Relatively high and constant efficiency.
  • PWM can cause problems for video or photograpy due to the relatively low frequency that is used. This low frequency PWM can ‘beat’ with the camera frame time to cause banding as the LED turns on and off within a single frame.

Disadvantages:

  • More expensive and complicated design
  • Voltage of the battery must be at least a bit higher than the LED voltage.

 

Boost Driver

This is a more complicated design, also called as step up driver.

This is very similar the the Buck Driver, but as its name implies, it will increase the voltage (Buck driver decrease the voltage).

It can also be used to power a multiple LEDs in series.

An example would be using 2 li-ion batteries in series (8.4V fully charged) to drive 4 series connect LEDs with a total Vf of around 13.2V. A boost driver will draw higher current from the input than what it will provide at the output. As the battery voltage drops, the boost driver will draw even more current and this tends to put more strain on a battery pack that is already fairly discharged.

Advantages:

  • Can be used with batteries that have a voltage lower than the LED voltage.

Disadvantages:

  • More expensive and complicated design
  • Voltage of the battery must be lower than the LED voltage.
  • PWM can cause problems for video or photograpy due to the relatively low frequency that is used. This low frequency PWM can ‘beat’ with the camera frame time to cause banding as the LED turns on and off within a single frame.

 

Buck Boost Driver

Combined buck-boost drivers tend to be less efficient that a straight buck or boost driver. Where a typical buck or boost driver can run at 90% efficiency (or higher) a buck-boost would likely be around 80%. There are some efficient buck/boost designs, but they cost more to manufacturer.

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Mistral XM-L2 technical dive light

Mistral XM-L2

 

Delivering breakthrough lumen output and efficacy in the XM package, the XLamp® XM-L2 LED is the highest-performing, commercially-available, single-die LED. Built on the SC³ Technology Platform, the Xlamp XM-L2 LED delivers up to 20% more lumens and lumens-per-watt and double the lumens-per-dollar of the original XM-L. The XM-L2 LED offers the unique combination of high efficacy and high lumen output at high drive currents.

        • Max. power 10 W
        • Max. light output 1198 lm
        • Color temperature 6500 K
        • High quality TIR optics
        • FWHM 4,9°
    • Aerospace grade anodized aluminium light head that optimizes head dissipation and protecting LED electronics and optics
    • Constant current LED driver
        • 3 modes
          • 25% pwm
          • 50% pwm
          • 100% pwm
    • Piezo switch
        • Solid stainless steel body
        • Sealed to IP69K
        • Easy to clean metal surface
        • Long life (million cycles)
    • Adjustable laser cutted stainless steel goodman handle
    • Nickel plated IP69K rated brass cable glands
    • Aerospace grade anodized solid aluminium canister body and lid
    • 11,1 V 10500 mAh Li-ion battery pack with integrated BMS system
    • Dual o-ring protection
    • Gold plated banana plugs
    • Stainless steel Nielsen latch

    • Sealed battery compartment with pressure release valve

    • Every light is tested at 20 bar (~200 meter) for 60 minutes

    • Drysuit heating port (optional)

Mistral XM-L2 optical performance

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What is the difference between Lumens, Lux, Watt, Lumen per watt and color temperature?

When buying a new dive light, it is easy to get confused about the different terms that are used to describe the most important parameters of the light.

LUMENS

Lumen is a unit of light, which is also known as Luminous flux. Lumens (lm) are a measurement unit, which tells what the total amount of light emitted from a dive light. You can roughly say that the more Lumens the brighter the light.
When we specify our dive lights, we use Lumens to see the total amount of light output. But Lumens will only show us a part of the picture. Producing a perfect beam shape does not reveal enough information to show us how the light output is created. For this we need a lux meter.
To measure the total amount of lumens, an integrating sphere is necessary. An integrating sphere (also known as an Ulbricht sphere) is a hollow, spherical chamber coated internally with a high reflectance coating that exhibits diffuse reflectance. Spheres are used as directionally-insensitive collectors of light when combined with photodetectors. An internally illuminated integrating sphere emits a field of spatially and angularly uniform luminance or radiance which is perfect for testing led lights.

LUX

Lux (lx) is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. One lux is equal to one lumen per square metre. In photometry, this is used as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface.

Lux is much easier to measure than Lumen. Lux can be measured with a hand held device.
If the light output is focused on a small area (narrow beam), we see this as very bright light. If the light output is focused on a greater area (wide beam), we experience this as a weaker light.

WATT

Watt (W) is a derived unit of power in the SI units, defined as 1 joule per second and can be used to quantify the rate of energy transfer. It shows how much energy the product consumes, not how much light output (lumens) it provides. For this reason you should not only look after the amount of watt consumed, when select a dive light. It will just tell you how quickly it will drain your battery, and not how much light it produces.

LUMINOUS efficacy

Luminous efficiency is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power, measured in lumens per watt  (lm/W) in SI unit.

COLOR TEMPERATURE

The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of a color comparable to that of the light source. Color temperature is conventionally expressed in kelvins (K) is the SI unit.

Color temperatures over 5000 K are called “cool colors” (bluish white), while lower color temperatures (2700–3000 K) are called “warm colors” (yellowish white through red). “Warm” in this context is an analogy to radiated heat flux of traditional incandescent lighting rather than temperature. The spectral peak of warm-coloured light is closer to infrared, and most natural warm-coloured light sources emit significant infrared radiation.

The Sun closely approximates a black-body radiator. The effective temperature, defined by the total radiative power per square unit, is about 5780 K. The color temperature of sunlight above the atmosphere is about 5900 K.