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Connecting the N8034 Ditchlight Simulator
Installing the N8034 is very straightforward. Its tiny size and thin construction will allow it to be placed in many spaces too small for even the smallest Z-scale decoder. Because the module has circuitry on both sides, care must be taken to be sure that the components or wires soldered will not make contact with any metal object (such as a locomotive frame) causing a short circuit.
If the N8034 is to be used in a stationary (not track powered) application, it can also be powered by any well-filtered and regulated DC power source with an output of 6-18VDC.
Included with the module are three 6” lengths of #32 insulated wire. If necessary, these can be used for power input and function control wires.
Most wired decoders have a blue wire which is the common connection for all wired functions (F0, F1, etc.). It is the + DC connection and will be connected to solder point #1 as shown in Fig. 1.
If the decoder is a “drop-in” style without wires, consult the decoder manual and use the blue wire supplied to connect point #1 to the appropriate + solder pad.
If the solder pad has a resistor in series with it, be sure to connect the blue wire behind the resistor (see Fig. 2). This will ensure full voltage is supplied to the module.
Important note: A low-wattage iron with a pointed tip should be used for connection of wires. Too much heat or solder can easily damage the wires, decoder or module and void the warranty.
Also, all connecting wires should be pre-tinned before soldering them to the module. This will make connection quick and easy and ensure excessive heat is not applied to the solder points.
Next, choose the function you want to control the N8034 module and connect the appropriate function wire to solder point #2. For example: If you want F1 to turn on the Mars light, connect the green wire to #2.
Again, if the decoder is the drop-in style, use the enclosed green wire to connect the appropriate function solder pad to #2. Make sure the pad chosen for this connection is not a “+” pad , but a function pad (– DC connection).
Whichever function you choose, make sure it is programmed for On/Off control only. Do not program the function for special effects. The N8034 will control the special effects.
Direct Track powering (without a decoder connection)
All of our Simulators require a clean DC voltage of known polarity for their power source. Track power is typically provided in one of two forms. DC voltage (analog), or DCC.
Analog track power has been around for more than 75 years. Simply put, a DC voltage is applied to the two tracks with one being +DC and the other, -DC. Increase the voltage and the electric motor in the locomotive spins faster making the train go faster. If the train is required to reverse, track polarity is reversed so the loco's motor turns in reverse. Also, what defines "forward and reverse" is dependent on which way the loco is facing when it's put on the track. Bottom line here is that track polarity is not fixed. Our Simulator needs fixed polarity.
DCC track power is such that to devices requiring plain DC voltage, it looks like AC power. That is because voltage levels on each track go both + and – continuously. The DCC decoders in locomotives “descramble” the track signals and provide correct polarity so their motors can function normally. It is this process that will allow multiple locomotives to go in different directions on the same section of track, at the same time (a feature not available with analog track power). Once again, our Simulator needs fixed polarity and it needs to look like DC voltage.
Due to our Simulator's very small size, there is insufficient space to include additional circuitry and components necessary for proper power conditioning when direct track pickup is to be used. There are two solutions to this problem and both are inexpensive:
When connecting the LED, proper polarity must be observed. LEDs are “polarity sensitive” and will not function if connected backwards. The N8034 is configured to connect to a 20 ma LED with a device voltage of 3.3-3.6 VDC. This covers all of Ngineering’s white, yellow-white and incandescent white LEDs, as well as most of the white and golden-white LEDs available.
Using wire appropriate for the size of the LED and its placement in the locomotive, connect one LED cathode (the – connection) to point 3 on the module and connect the LED anode (the +) to solder point 4. This LED will use the on-board 81Ω current limiting resistor so it can be wired directly. When connecting the second LED, an external resistor must be wired in series with that LED. Included with this module are two 1/8-watt 81Ω surface-mount resistors (we’ve included a spare just in case).
This resistor is just like the one on the module and has pre-tinned tabs so soldering is easy. The second LED’s cathode is to be wired to solder point 5 on the module. The resistor should be wired in series with the second LED’s anode and point 6.
See Fig. 5 below for a complete overview of wiring.
Once again, be sure to use a low-wattage soldering iron when connecting wires to the module.
Our N40M2 12-watt Iron with either the N408I (iron clad) Needle Tip, or the N408X (bare copper) Needle Tip would be an excellent choice for this operation (or any DCC decoder work).
Basic operation of the ditchlights (both ditchlights either on or off) is controlled by applying power to the module’s DC inputs (points 1 & 2). Wiring for this is covered above. Included with this module is a 6” length of violet #32 wire. If necessary, this can be used to connect solder point 7 to either a DCC decoder momentary function control (such as F2) or to an external switch (slide-switch, pushbutton or magnetic reed switch) which is then connected to DC – (ground).
The microcontroller on this module has been programmed to “latch” when point 7 is momentarily grounded , turning on the alternating ditchlight effect. This effect will stay in operation until point 7 in again momentarily grounded, which will return the ditchlights to both on continuously. When grounded again, they alternate again… and so on. This latching feature allows for quick and easy throttle function control, such as when passing through multiple grade crossings or station approaches.
If automatic control is desirable, point 7 can simply be wired through a miniature reed type switch to ground, with the reed switch placed low on the underside of the locomotive so it can be triggered by magnets buried at track level. One magnet prior to the crossing to turn on alternating ditchlights, another after the crossing to turn them off.
This completes hookup and operation of our N8034 Ditchlight module. We hope the added realism it provides enhances your enjoyment of the hobby.
© 2008 Ngineering