The F_Tech Driver. Geeky stuff.

The driver circuit is most easily understood if considered as being composed of two separate modules, the high efficiency buck driver and the analogue controller. The driver is based on a chip that accepts an analogue voltage signal to control brightness, rather than the usual Pulse Width Modulation (PWM). If the latter needs explanation, you can read all about it in Wiki. Biggest problem with off the shelf and cheaper drivers is falling output as the battery goes down, and also poor efficiency at lower brightness levels. This is basically what you can expect to get in most Chinese torches and headtorches.  So how bad are the poor ones? I could say but would probably be disbelieved! At lowest outputs the eastern product is as bad as 68% efficiency, however I cant make a direct comparison as mine does not have an equivalent output, but standard mode on mine of 200mA runs on average 85% efficient, high mode averages about 95% efficiency.

The driver circuit is not complicated, basically typical buck circuit except the 3 or 4 mode analogue controller is of my own design which as an assembly gives a very consistent, efficient, and completely flicker free output on all brightness levels, and the consistency of output to the point where voltage in falls to the voltage of the LED array is very consistent and smacks of a boost driver although it is not. In effect, there is no falling off of output down to where the lamp powers down to “slow death” mode, bar the Turbo made. And that is sustainable for most of the battery life.

The new FT 8 is very much unlike the previous X in that it utilizes a compound reflector that makes best use of the light output without turning the underground into "Tesco". The single push button of the old Scorpion X is moved to the side enabling more rear heatsinking. It operates on 3 modes, simple and straightforward.

The more powerful  NT 12, is similar in appearance to my old X12, the two vertical reflectors with a bare emitter each side, this suggests an 8V input, but its not, it’s a 12v model. The two bare emitters are parallel wired and then serial wired to the 2 serial emitters behind the reflectors. Both lamps have indicator LEDs mounted each side of the reflector, green power level OK, and flashing red warning low power. 

The FT 12 placement of the bare emitters gives a better external appearance as well as sharing the power and the subsequent heat generated between both sides of the lamp. This one will never burn out a flood, the weak point on many lamps.

This lamp is actuated by a double throw momentary toggle switch mounted on the same side of the lamp as the cable gland. It does look rather good as well as being extremely user friendly. Flicking down is ON/OFF, up is mode cycle through the 4 modes. Flicking up with lamp off enables the 4 blue LED battery meter, it works with it on but advised to use it lamp off.

The new lamps have virtually nothing sourced from the Far East; all electronic and major components are from major western manufacturers. All the electronics are my own design, bar the main driver circuit which is based on the manufacturer’s data sheet ‘typical application’ schematic.