MTH Operating Passenger Station Question

Dan: This should work. The relay on the sensor module is rated at 2 amps which should be okay as long as the solenoid in the station doesn't overheat.

Good luck!

  -- Leo

Thank you Leo.  I'm going to print that diagram and try it over the weekend.

Dan Padova wrote:

So when the RDC pulls in, the passengers would disappear.  Then when the RDC arrives the next time, the passengers would reappear.

The wiring diagram that I sent does not account for the station keeping the passengers hidden for as long as you have specified here. Unless I misunderstand what the station is doing, the passengers will return as soon as the insulated rail section is clear. Timing is still an issue.

You can sort of control the timing by extending the insulated section in one direction. Another option is to use a large capacitor that you would have to solder onto the sensor module (see J2 in the instruction sheet). GRJ put that in to allow a brief delay before the relay is deactivated. The maximum delay would be about 5 seconds.

I'm not sure that holding the solenoid in the station for as long as you want is a good idea. Operationally, yes. But I thought the instructions warned about it overheating and that there is a fail-safe built in to turn it off should that occur (some sort of self reset thermal breaker). If that happens, it says that you need to turn off power to the unit for 10 minutes. You wouldn't want that.

It would be better if the station were driven by some other mechanism that would allow it to be activated for as long a period of time as required. But with what you've got, I would not want it on for very long. Here are the instructions for the MTHstation.

Great diagram Leo. 

OP needs to clarify if he really wants the passengers to disappear on one pass, re-appear on the next pass, alternating.  As you say, that is something the ITSD or even an ITAD does NOT support.  As drawn, passengers would disappear when the train triggers the ITSD....then re-appear when the train no longer triggers the ITSD.  As you say, a capacitor can be added to delay when the passengers re-appear.  Per the ITSD instruction sheet, this delay is proportional to the size of the manually added capacitor (1000 uF per second).  For long delay of 5 seconds or more, the capacitor gets physically large though inexpensive ($1-2 or so).

I don't have one of these, but as suggested in the above photo of the switch assembly, it appears they use a simple toggle switch for manual operation.  This tells me (I may be wrong of course) that you can indefinitely apply NC or NO power.  In other words it is safe to have the passengers present or absent indefinitely.  The way I read it, the thermal protection is for the case where the mechanism gets stuck in the middle.  I equate this to the standard solenoid turnout-switches where the solenoid turns off when reaching the other position (straight or diverge) so you can hold down the turnout controller lever in either position indefinitely.  The bad case is if there's a mechanical obstruction on the turnout preventing the solenoid from fully moving the points to the other position.

In any case, if the goal is to automatically alternate between passengers present and passengers absent on each pass, as you say something else needs to be done.  I'd imagine some eBay relay modules could be cobbled together to do so for less than $10 out-of-pocket.  

Stan and Dan: If the buzzing of the solenoid is not a concern, and the overheating problem only occurs when the lift arm gets stuck, and the controller doesn't use a return to off spring switch, then I won't worry about the length of time that the solenoid remains engaged. That buzzing sound is part of the charm that I grew up with from the trains.

 But to get the alternating action that Dan mentioned, it would take something more; a flip-flop, a divide by two counter, cascading relays, something like that. By the time I think of how this could be rigged, Stan will already have thought of a solution. But I'll think about it myself anyway.

@stan2004 posted:

Great diagram Leo.

OP needs to clarify if he really wants the passengers to disappear on one pass, re-appear on the next pass, alternating.  As you say, that is something the ITSD or even an ITAD does NOT support.  As drawn, passengers would disappear when the train triggers the ITSD....then re-appear when the train no longer triggers the ITSD.  As you say, a capacitor can be added to delay when the passengers re-appear.  Per the ITSD instruction sheet, this delay is proportional to the size of the manually added capacitor (1000 uF per second).  For long delay of 5 seconds or more, the capacitor gets physically large though inexpensive ($1-2 or so).

I don't have one of these, but as suggested in the above photo of the switch assembly, it appears they use a simple toggle switch for manual operation.  This tells me (I may be wrong of course) that you can indefinitely apply NC or NO power.  In other words it is safe to have the passengers present or absent indefinitely.  The way I read it, the thermal protection is for the case where the mechanism gets stuck in the middle.  I equate this to the standard solenoid turnout-switches where the solenoid turns off when reaching the other position (straight or diverge) so you can hold down the turnout controller lever in either position indefinitely.  The bad case is if there's a mechanical obstruction on the turnout preventing the solenoid from fully moving the points to the other position.

In any case, if the goal is to automatically alternate between passengers present and passengers absent on each pass, as you say something else needs to be done.  I'd imagine some eBay relay modules could be cobbled together to do so for less than $10 out-of-pocket.  

Do you have a part number for that ???

What is "that"?

Are you trying to do the alternating behavior like the OP? What are you presently using to trigger the station?

Reminds me of my smart IR detector activated passenger terminal.

https://www.youtube.com/watch?v=P8NJN1vCfCU

It occurred to me that alternating accessory behavior could have applications beyond the operating passenger station.  That is, when a train passes the occupancy detector (ITAD, insulated rail section, whatever) the trigger alternates between two outcomes.  This can add interest to a layout.  I suppose a simple example would be to toggle between two routes on each pass...though I realize there are other methods to do this.

For proof of concept I used an MTH Realtrax ITAD.  The key is a so-called "bi-stable relay".  I don't know if there is "official" terminology so you have to read the description - terms like toggling relay or flip-flop relay may also apply.  You want a relay that alternates between two outputs upon each trigger.  These are just a few bucks from eBay Asia...or spend a bit more $ on Amazon to get faster shipping.

These modules are DC operated.  I happened to have one that operates 12V DC.  An ITAD can be operated on AC or DC so in the following, everything is running on 12V DC which can be obtained from a 12V DC-output wall-adapter / wall-wart.  Wiring is required but no soldering. Here it is in action.

I do not have an operating station but in the video the red and green lights simulate driving the platform between the arriving and departing conditions.

There is some fine-print on how to hook up this particular bi-stable relay module which I can elaborate on if there's any interest.  With some additional consideration, this could even apply to insulated-rail triggering to alternate accessory action on each pass of the train.