Is it possible to have a non-rotary (i.e. blinking LED light) beacon on the tops of locomotives in N scale?
What peaked my curiosity was an advertisement for blinking LEDs that did not need an integrated circuit board to blink. You just hook them up to a power source, and you’re golden.
How was something like this be hooked up to a Kato N scale SD40-2 with the DCC decoder?
The blinking LEDs are just regualr LEDs with a blinker circuit integrated into them. I haven’t seen any that would be small enough for N scale, most of them are too big even for HO. A seperate blinkign circuit would allow uou to use tiny surface mount LEDs int he beacon, which are small enough for N scale - of cource you need to find room for the circuit.
–Randy
What is the prototypical size of a beacon in real life and in N scale?
Say I bought a very, very small surface mount LED. Where would I hook up the power wires in an N scale engine that has a drop-in DCC decoder? What about hooking up the wires to the black and red leads from the track pickup (i.e. 14.1V from the track in a DCC system)?
The LED would make a very brief flash and be immediately destroyed. An average LED requires no more than 1.2 to 3 Volts at only 15mA or so. The 14 Volt square wave DCC track power would cause it to burn out instantly without a current limiting resistor in the circuit, usually in the range of 1,000 Ohms. I know of no surface mount flashing LEDs – most are 3mm or larger. I’ve even known of cases where an LED would explode with a very loud pop and throw shards of plastic for a long distance when connected to the wrong voltage.
If the decoder inside your locomotive has the capability of connecting additional lights and can be programmed for a flashing beacon, an LED could be connected to the decoder’s function output, but this, too, is going to require a resistor or you could destroy the decoder as soon as you turn on the beacon. In order to do this, you must determine exactly what type decoder is in the loco and then read through the decoder manual to see if it can be programmed for a flashing beacon and which function wire is available. You need to also be aware that an LED is a polarity sensitive device, and if you get the wires backwards it won’t work.
Thanks for the reply.
I have the MRC 1806 sound and motor DCC decoder for the Kato N scale SD40-2. It’s a board, so not sure where the hookups would be for extra lights and whatnot. Guess I’ll have to check.
It can’t be done – the MRC 1806 does not have any light hookups other than the headlight.
You might want to take a look at what Ngineering has to offer.
What if I soldered the N8032 beacon simulator to the headlight LED connections on the board (i.e. in parallel)? Would that work?
Not exactly. It can be wired in parallel to the LED, but there will be a current limiting resistor on the decoder for that LED and the N8032 would have have to be wired in before the resistor.
I’ve never tried wiring two LEDs that way, but my opinion is that each time the strobe turns on or off the headlight LED would get dimmer and brighter due to the current being drawn away from it. This may also overload the headlight function output of the decoder and shorten its life.
This is copy and pasted from the above website:
Installing the N8032 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 N8032 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 two 6” lengths of #32 insulated wire. If necessary, these can be used for power input 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.
Figure 1
So I could use the N8101 circuit to connect to the track pickup wires. In other words, since N scale locos are a split-frame mechanism. I can solder a small red wire to one side of the chassis frame, and solder a small black wire to the other chassis frame. I can then solder the the red and black wires to the track pickups to the indicated leads on Figure 4 above.