Flexitwin V5 operation in variblend modes

The Flexitwin V5 is expected to be used overwhelmingly in the variblend modes, described below.
In this mode, the light is run with the power switch on the left side of the Duo in the centre ('off') position.
In all modes, the focussing control on the right hand side of the Duo does nothing useful and should be left alone.

Down controls power levels (and 'off')

To cycle through the power levels (high / medium / low / extra-low) the switch is briefly 'blipped' down and then back to centre to nudge the power level onto the next one in sequence without affecting the beam blend.

To turn the unit off, the power switch is moved down and left down for at least 2 seconds. After 2 seconds, the output drops to a low power flood beam, and will then turn off when the switch is centred.
This operation ensures that the unit is easy to turn off, but also that it cannot be completely turned off accidentally by leaving the switch down unintentionally - the low power flood acts as a pre-off warning signal.

Up controls beam blend (and reversible 'spotting light')

From the centre operating position, quickly blipping the switch up and back down to centre changes the beam blend of the light (the fraction of the total power going to the flood and spot LEDs) without affecting the total output power
The available beam blends are in a repeating sequence of:
100% flood / 10:1 flood:spot mix / 3:1 flood:spot mix / 1:1 flood:spot mix.

If the switch is moved up and left up for more than ~0.7s, the spot beam will come on at full power to allow for illuminating remote targets, checking out routes, passages, pitches and avens, etc. On returning the switch to the centre position the unit will carry on where it was before the lever was moved up, so providing instant but reversible access to a bright spot beam.

For users wanting even simpler operation, the V5 can be configured to drop the number of power levels and beam blends from 4 to 3, removing the extra-low power level and the 10:1 beam blend. This still leaves the user with an extra-low flood beam setting available when the switch is pushed down and left down.

Power ranges

To cater for various different user requirements, the Flexitwin can be operated in one of three power ranges - Standard, High, or Boost. In variblend mode, these ranges operate as follows:

In the Standard power range, the maximum power consumption is ~350mA, with maximum light output of ~160 lumens, with lower power levels each being 40% of the power consumption/output of the next-higher level.

In the High power range, the maximum power consumption is ~twice that of the standard range, with maximum light output of ~320 lumens, and levels stepped apart a little wider than the standard mode, giving similar power consumption at the lowest power level.

In the Boost power range, all the power levels are the same as the Standard range, with the exception that the high power setting runs at a boosted level for the first minute after selection. This boosted level is twice the standard power for all blends other then the 50:50 blend, and three times the standard for the 50:50 blend, giving outputs of 320 and 450lumens respectively.
After the first minute, the power level is smoothly reduced to the standard level over 30 seconds, slowly enough to be hard to notice.

Range selection is very much a matter of taste. It is expected that the default boost range wll be the most popular, but the standard and high ranges are available to maximise user options.