NJG-18 3-Watt LED driver board adjustable to accept from .8 to 7 volts input using a step up voltage circuit. This is a step up voltage board; it will drive voltage to the set output, if the output setting is exceeded by the input it will go in to direct drive. Using a single 1.2 volt Ni-MH battery, this board is capable is driving 700mA up to 4 volts (3 watts). With an adjustment potentiometer, this driver board can accept a range of by battery chemistries and combinations including alkaline, Ni-MH, Lithium primary, and Lithium Ion up to 7v input.

The NANJG-18 LED driver boards have a microprocessor onboard which is programmed at the factory to control the modes. This board has been programmed for three selectable groups of modes.

This board comes pre-set for 3.7v output; without any adjustments, it can be used with a single: Alkaline, Ni-mh, Lithium, or Lithium ion battery to achieve 3.7v driver output voltage. 

Specifications:

Input voltage range: .8 -7 volts
Output voltage range: 2 -7 volts
Regulation: (Step up when input < output setting) (Direct when Input > Output setting)
Diameter: 17mm
Height: 5mm (measured height from board surface to top of the inductor )

Mode groups:

1) Low, Med, High (no strobe or blink modes)
2) Low, Med, High, Police Strobe, SOS
3) Low, Med, High, Police Strobe, Slow strobe (3HZ), Extreme slow strobe (1HZ), SOS

Changing modes: Modes are switched such as (Low --> Medium --> High --> REPEAT) by momentarily interrupting the power. Immediately after turning the light on, tap the power switch to quickly interrupt the power, this will signal the driver board to change output modes. Modes are remembered if the power is left off for more than two seconds.

Changing Mode Groups: Mode Groups are changed by turning the light on, selecting the Low Mode and after about 4 seconds the light will blink, at this time, turn the flashlight off and wait 5 seconds. When you turn the light back on it will be in the next group of modes.

Notes:

The stock setting is when the flatted side of the potentiometer is facing the 215 resister  and the text on the board "R1"; this will boost any voltage below 3.7v up to 3.7 volts. You may need to look closely to discern the flat side but it is there. Turn pot counter clockwise to increase output voltage.

The stock setting on this board was tested under load on HIGH as follows.

SSC U-bin Measurements under load at stock setting:

1.2v @1.2A In --> 3.2v @ .3A (measured at the emitter)
3.8v @.56A In --> 3.2v @ .485A (measured at the emitter)
4.1v @.54A In --> 3.2v @ .5A (measured at the emitter)

CREE Q5 Measurements under load at stock setting:

1.2v @1.2A In --> 3.2v @ .175A (measured at the emitter)
3.8v @.56A In --> 3.2v @ .250A (measured at the emitter)
4.1v @.54A In --> 3.2v @ .275A (measured at the emitter)

Note: ~1/8 turn counter clockwise increased the drive current of the Q5 to ~800mA; this is where I set the pot for driving a Q5.

It is important to have very good electrically conductive paths for the driver board to avoid flicker, ringing and poor performance. Ensure your pill (sandwich, module....) has a solid path from the negative input of the board to the body of the light; ensure that the threads of the flashlight body also provide a good conducting path. A poor installation will result in poor performance.

As a DIY part, driver boards are used in many configurations, whether correct or not. These drivers are offered for customization, modification and experimentation, due to their high susceptibility to damage we do not warranty driver boards.

The board comes with leads which are not pre-attached, if you would like them pre-attached please select this option below.