Rule 17 lighting

There are quite a few  rules under rule 17

, ex    the headlight will be dimmed when standing on yard tracks

when standing on the main track at the meeting point after the switch has been lined for the siding

Approaching stations where trains are receiving or discharging passengers.

 Approaching stations where train orders or clearances are picked up.

Exceptions ,  full power approaching all public crossing at grade

I would think any time the   headlight is dimmed or extinguish (rule 17) the mars light would be turned off.

Stopping on the main track  to inspect a car or  waiting  for a permissive signal  would not be a reason to dim the headlight.

  Backing up.... The engineman would just leave the headlight on and perhaps turn on the rear headlight. (depends on what they're doing)

Of course, emulating all of these situations would be pretty difficult without a lot of expense.  I live with dimming the headlight when I stop, pretty much the same as MTH and Lionel do now.

Think also when trains pass other oncoming trains they dim the headlights so as not to blind each other.

I'm wiring up a second motion detection circuit and will try to dim the MARS light first. The MARS light on the PS1, GS4 is powered by a 6V regulator with a flash circuit that plugs into the main regulator board. If the flash circuit plays well with my motion detection circuit I will just dim it to match the headlight. If they don't play well due to the flashing I will turn it off.  Getting kinda crowded in the boiler, glad it's a large loco. Thanks for the input gentlemen.  J

Just realized that all it would take is one more diode to make the motion detection circuit direction sensitive so it could go off when backing. That begs the question if you dim it when the loco is stopped is it more appropriate to keep it dimmed when backing or turn it off. J

Would you mind sharing your circuit diagram?  I'm working on something similar...

Casey Jones2 posted:

Think also when trains pass other oncoming trains they dim the headlights so as not to blind each other.

 

 

 

Recreating every Rule 17 scenario  would be too complex to get the circuit inside a 1/48 scale loco. However I think dimming the headlight could be done with UV LEDs and UV sensor so as to not be sensitive to all other lighting.  All of your locos would need to have at least the UV LED on each end of the loco or lash-up and you might end up with headlights constantly going hi-lo-hi on a small layout where several locos near by  influence one another in other than Rule 17 situations.  Might drive me nuts.  Think I will settle for START STOP and perhaps BACK UP.      J

Volphin posted:

Would you mind sharing your circuit diagram?  I'm working on something similar...

 

When I have finished tweaking it I will post photos and description. However Gunrunner has posted a well working circuit.  Mine is much simpler, does not need a PC board and most anyone who can solder can hook it up.  J

Here's my circuit, I've also previously offered kits of parts and a PCB to build them.  Obviously, you'd want to have some SMT soldering experience.

Note: If you wanted this to only activate in one direction, you could replace the AC opto-coupler with a DC model, that would prevent it from activating in one direction.  Since the motor leads are totally isolated, you could simply swap them to change the direction of activation.  Since I wanted it to trigger whenever the locomotive was moving, I used an AC opto-coupler.

This is a completed module.

Here's the schematic of the module. 

Here's a sample application schematic with it wired into a locomotive.  This application was done to offer Rule-17 lighting control, automatic cab light control, and two-level smoke control, it drops the smoke volume when you're not moving.  As you can see, this is done for a diesel application.

Finally, here's the BOM with part numbers and quantities.

John, the project I'm trying to work out uses two,  2 color LEDs in an observation car (one LED per side, 2 colors in each LED).  I want them to glow white when stopped, and red when in motion (either direction). Could this circuit be modified for that purpose?  Power would be provided by a 18v tap into the lighting system.

Casey Jones2 posted:

Think also when trains pass other oncoming trains they dim the headlights so as not to blind each other.

Not during the day they don't 😉

Volphin posted:

John, the project I'm trying to work out uses two,  2 color LEDs in an observation car (one LED per side, 2 colors in each LED).  I want them to glow white when stopped, and red when in motion (either direction). Could this circuit be modified for that purpose?  Power would be provided by a 18v tap into the lighting system.

Seems GRJ is off for the night, the short answer is yes. John's motion detection circuit uses a DPDT relay output that can be wired to do just what you want with the red/white LED. It can be wired to reverse the polarity to the LED which changes the color. Or to route the current to the proper element in a three lead bi color LED. The next question is whether it is a two or three lead LED ?   Question two is more a statement, the motion detection circuit connects directly to the motor in the loco so it would require wiring to run the length of the train to reach the observation car. A simpler system might be a timer circuit that resets each time a magnetic reed switch is activated by a magnet on one of the observation cars wheels if it does not get triggered in say ten seconds the  light changes to white. There are cheap, small timer circuits on eBay that could be triggered by such a magnetic reed switch. With this system no need to run wiring from the loco to the observation.   J

I can't see running a wire to the engine as being very practical.  I was thinking of some sort of small accelerometer or optical sensor to trigger the change.  LEDs have not arrived yet but I think they are 3 lead LEDs.

For an observation car, the magnet idea is probably more appropriate, I do indeed depend on a direct connection to the motor for my motion detection.

I think you'll find an accelerometer to be troublesome, once you reach a set speed, it'll think you're stopped.   An optical sensor or a magnet on a wheel will probably be the solution.