FW3A, a TLF/BLF EDC flashlight - SST-20 available, coupon codes public

Some extra info about the light…

FW3A Interface

The FW3A uses the Andúril‎ firmware by ToyKeeper. It is similar to Tom E’s fantastic NarsilM, but with some extras.

Basic usage is very simple: Click for on/off, hold to change brightness. But there’s much more available for those who want it.

This is the UI diagram for it, showing most of the functions:

The interface uses mostly the same ramping as Narsil, and basic usage is identical. Click to turn the light on or off, hold the button to change brightness. However, this style applies to both the smooth ramp and the mode group, and the user can switch between them with three clicks while the light is on. No need to remember two interfaces or navigate a config mode.

Ramping also has some additional usability tweaks. If the user holds the button, ramping will always go up unless the button was released less than a second ago or it’s already at the top. To ramp down without ramping up first, do a “click, release, hold”. This eliminates the need to remember which way it was ramping in the past.

Both the smooth ramp and mode group are configurable. The user can set the lowest level, the highest level, and (mode group only) the number of steps. Full turbo is still available via double-click even if the ceiling is set somewhere more sensible.

While on, a double click toggles between turbo and the memorized level. So, if you hear a noise and want full power for a moment, double click. When you’re done, double click again to return to the original brightness.

Two groups worth of blinkies are included. To reach them, do “click click click” from off or a “click click hold”. These include:

  • Group 1: (always starts at battcheck)
    • BattCheck: Show remaining charge in volts and tenths.
    • Sunset: Start at “low”, then slowly ramp down to moon for an hour, then turn off.
    • Beacon: Blink once every N seconds at the last-ramped level. N is configurable.
    • TempCheck: Show current temperature and optionally configure settings for thermal regulation.
  • Group 2: (remembers the last-used mode)
    • Bike flasher: Steady output with a “stutter” once per second. Adjustable brightness.
    • Party strobe: Motion-freezing strobe. Adjustable speed.
    • Tactical strobe: Bright, disorienting strobe. Adjustable speed.
    • Lightning storm: Exactly what it says on the tin. No adjustments available.
    • Candle: Simulates a flickering candle or fireplace. Adjustable brightness. Also works as a self-shutoff timer in 30-minute increments.

A few other modes are available by clicking even more times from off:

  • 4 clicks: Soft lockout. Light won’t turn on until it’s unlocked. This mode doubles as a momentary moon mode, so when the button is held down it’ll light up at the current ramp floor. This is handy for checking something quickly without having to unlock the light.
  • 5 clicks: Momentary / signalling mode. Using the last-ramped brightness, the light will be on when the button is held, or off otherwise. Good for Morse code and such. To exit this mode, physically disconnect power (unscrew the light).
  • 6 clicks: Muggle mode. An extremely simple interface with a limited brightness range — ~10 lm to ~300 lm, with smooth ramping and no blinkies. Persists after a battery change. To exit this mode, quickly click exactly 6 times.

Some features which aren’t visible on the diagram:

  • Low voltage protection will reduce the brightness when the battery is low. If the brightness is already down all the way, it will shut the light off entirely.
  • Thermal regulation keeps the light from overheating. It’s not normally visible by eye though; it ramps smoothly across 512 internal steps to adjust output while it searches for the highest level it can maintain without overheating.
  • By default, the ceiling is set to the highest fully-regulated output level — 3 Amps. This is about 1000 lumens. Full turbo is about 3000 lumens, but cannot be sustained for long due to the heat it creates.

There are also some other interfaces available for this hardware, but it requires the user to flash different firmware. You can make it work like a BLF Q8, or like an Olight, or like a Zebralight, for example. However, these are not tested and not officially supported.

Driver

The FW3A uses a FET+7+1 driver.

So, three power channels:

  • 1xAMC7135 chip for 0 to 350mA
  • 7xAMC7135 chips for 350mA to 2.8 A
  • FET for 2.8 A to full power (direct drive)

This keeps most of the levels pretty stable and reasonably efficient, as far as linear drivers go. But it still has a direct drive circuit for turbo.

In a totally non-scientific qualitative manner, the overall efficiency curve compared to a constant current linear driver looks something like this:

LEDs also change tint according to the power level. This driver attempts to minimize that effect by blending power channels, but it may still be noticeable. The curve for that looks roughly like this:

Optics

The optic is a Carclo 10511, which is a lightly frosted optic with a relatively narrow spot. It gets almost as much throw as the 10507 optic, but with greatly reduced tint shift and artifacts.

BLF user maukka measured this in great detail in his review, which is quoted here: