Illumination unit NF-3XLF

NF-3XLF unit is designed for illumination of big models with wingspan two meters and more.  It is used to power color ultra bright LEDs (Light-Emitting Diode) with the nominal current of 80, 120, 150, 350 or 700mA. The unit contains seven independent current-powered outputs. Two outputs are for position lights (P1, P2), two outputs are designed to power the anti-collision flashing lights (F1, F2) and two outputs power the landing lights (L1, L2). Switching on of the second landing light output is delayed by one second against the first landing output. That produces an effect of phased switching by the pilot. Moreover, the unit has an extra illumination output of 20mA for cabin illumination or for background illumination of board instruments (I1). The output is switched on together with position lights.   

The unit offers eight different flashing combinations (0 -7) with one second period for F1 and F2 outputs. See the diagram on the left side. One of those combinations can be selected by couplers (jumpers) 1, 2, 4. The sum of numbers of the connected couplers represents the number of the selected combination. By default, the unit contains six combinations of 1, 2 and 3 mutually shifted flashes plus two flashing modes 1:1, one with the period 1s, the other twice faster. Eventually, customer can propose other combinations and try them using a program simulator, store them into a file and ask them when ordering new unit. The program simulator is available on the Web.

The unit can be used as controlled or non-controlled by pilot. If controlled by pilot, the jumper "3p" allows you to select between 2-positions (Fly/Landing) or 3-positions (Off/Fly/Landing) control by the remote controller. With a 2-positions control the position and anti-collision lights start work when the unit is connected to the accumulator. However, the landing lights can be switched on and off by pilot. In the 3-positions control system, all lights are off in the off-position. In the fly-position the position and anti-collision lights are on and in the landing-position, all lights are on. 

Unit is in non-controlled mode if the Rx cable is not connected to the receiver. In this case the lights start work when the unit is connected to the accumulator and the "3p" jumper can be used to switch manually the landing lights off. 

Anti-collision and landing lights automatically begin to flash when the plane is unable to receive a signal from the remote controller. The receiver circuit and the light circuits are electrically separated by an opto-coupler. Unit is compatible with Graupner or Hitec-type connectors.

The outputs maintain the nominal current in the wide range of voltage from 6V* to 14V without the need to connect compensating resistance series in the circuit. The stabilization starts working from 4.5V, therefore it is possible to connect the unit to a NiCd or NiMH batteries from 5 up to 10 cells or Li-Pol from 2 up to 3 cells. As the number of the cells of the powering accumulator increases, so does the number of diodes that can be connected (serially) on each output. Using seven-cell-accumulator, 2 green or white diodes or 3 red or yellow diodes can be connected into one output. It is only necessary to assume that the summa of voltages of diods plus 1,8V for output circuit functionality is below the voltage of accumulator, otherwise the luminosity od LEDs falls down.  The typical working voltage for red and yellow LEDs is 1,8V. For white and green it is from 3,0 to 3,3V. The colors of diodes in one circuit can be combined.  The diodes are powered from the positive pole of accumulator against the common negative pole.  The unit contains protection against reversal polarity connection to a power supply. 

The circuit regulates the output current by burning the voltage difference between supplied voltage and the diodes voltage on a power transistor with a heatsink. The least favorable situation is when the circuit is powered with a high voltage and a short-circuit happens on the output. At this moment all the power (output current multiplied by voltage) is converted to heat in the transistor. The outputs are designed to dissipate up to 2 W in the long term each. For the current 350mA ( = 0,35A) that represents a maximum voltage of 5,7 V for permanent short-circuit ( 2W/0,35A = 5,7V) . If at least one white diode is connected to the output, that improves the situation of the transistor leading to an operational voltage of 9 V (5,7 V transistor + 3,3 V diode). With a higher number of diodes, it is theoretically possible to use the circuits with voltage up to 17 V (12-cells-accumulator.)  However, the guarantee does not apply to use beyond 14V. The good experience is not to use the accumulator voltage higher than the necessary LED working voltage plus 2 or 3 V (as a reserve).  

Write a review

Manuals and Documentation Downloads

English Documentation