Secure Site

Shop with


What's New
Search Site
Lighting Products
Lighting Accessories
Lighting Effects Products
Lighting Kits
Little Sounds
Photo-etched Products
Stamped Metal Products
Other Detail Stuff
Soldering Aids
Other Cool Tools
Tips 'n Tricks
Ordering & Delivery Info

Best viewed using:

 Internet Explorer


Mozilla Firefox


Connecting the NL8014 (unidirectional) Constant Voltage Circuit


Connecting the NL8104 is quite simple. This circuit is designed for unidirectional track polarity and DC only (non-DCC) operation. This means that for normal (forward motion) operation, the + DC input connection is wired to the locomotive's engineer side track pickup, and the – DC input is to be connected to the locomotive fireman's side track pickup. Once wired this way, if track polarity is reversed, the circuit will turn off until track polarity is changed back. This feature will allow the headlight LED to turn off while the locomotive is in reverse operation.

Should your application require a reversing light to be active during reverse operation, a second circuit can be connected with the DC input wires reversed. We offer a 2-pack of this circuit for that purpose at a slightly lower individual price.

Figures 1 and 2 below highlight the components and connection points of the circuit..

                                                                       Figure 1

                                                                    Figure 2 

Primary LED connection:

Note: LEDs are polarity sensitive devices and must be wired with their anodes (+), and cathodes (–) connected to the proper solder points as shown.

The primary LED is assumed to be used for a locomotive headlight and is wired to the connection points shown above in figures 1 and 2.

Secondary LED connection:

This circuit board is configured for the connection of a second (optional) LED. There is a current limiting resistor already mounted on the board for this (second) LED, but to function, a tiny blob of solder must be placed as shown to connect this resistor to regulated +DC. DO NOT place solder on the two jumper pads shown as "DO NOT JUMPER!" This would connect the second resistor to –DC (ground) and the second LED would not function. Also, NEVER place solder blobs on both pairs of jumper pads. This would destroy the voltage regulator on the board.

Caution!    Carefully inspect all anode and cathode solder joints for solder bridges or shorted wires. Permanent damage to the circuit will occur if these outputs are shorted when power is applied.

Flicker control:

Another new feature we've added to our N8104 module is solder-points for direct wiring of external capacitors for flicker control. When connecting external capacitance for this purpose, if multiple capacitors are used, they must be wired in parallel (all + connections together, and all – connections together). They must have a voltage rating of 16-volts or greater. The + (plus) connections are to be wired to the solder point noted as "External capacitor + connection", and the – (minus) connections are wired to the "External capacitor – connection". A total of 400-600uf of capacitance should be sufficient for flicker control of 2 LEDs.


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).


This completes electrical hookup of the NL8104 Constant Voltage Circuit.


 Š 2014 Ngineering