I want to run a trolley layout with two lines that join at a switch and continue for about 2 sections of track before hitting a bumper and reversing. I don't want to have to constantly manually throw a switch to get the trolley to move over to the other line. Is there a way to have the switch automatically switch to the other line when the trolley passes the switch and hit the bumper and starts going forward?

Original Post

Easiest solution, put the switch machine button on the bumper and let the trolley push it. 

Otherwise, I don’t see why you couldn’t rig up an isolated section of track to activate the the switch motor like an anti-derail would function.

 

"Of course we know its O-gauge or no gauge." -- Sheldon Cooper

I did that with a music spring wire.  I run 3r trains back and forth 70'  between loops at eye level.  No switch machines, wires, toggles, electronics  or relays to buy, install or fail.  No drilling just remove a couple of spikes 7 ties in from the throw bar.  Bend a "Z" in the wire end, insert it in the throw bar.  Respike the wire along the stock rail then sit down with your  favorite beverage and watch them run.  It adds a background activity to my 2r RR.

IMG_8681IMG_9028

 

Eternity is a long time to have been wrong.

Attachments

Photos (2)

What he did was make a spring switch. Just like the real thing on some railroads. The wheels push the points to the side and when the train passes it snaps back. You just have to watch out that you don't reverse movement halfway through otherwise one end of the car goes the alternate route. 

Richard, sorry to say, but if I understand the situation correctly, nobody has come up with the solution to your problem yet.

Let me restate the problem as I understand it. You have a switch in your trolley route. You want the trolley to use leg "A", then return and use leg "B" on the next trip. Repeat A, B, A, B...

This is a more complicated operational pattern than simple solutions can handle. Short of an electronic solution, I think it can be done with a couple relays and three insulated sections, one located on the A and B legs and one on the common leg.

Here's the logic: If A then B next, if B then A next, where A and B are the route last taken.

The way this works is one relay keeps track of A or B and the other relay throws the switch and latches or unlatches the first relay.  Latching is when the power to the relay's coil is run through a set of the relay's contacts, thus holding it in the on condition. It doesn't matter which way it goes, but let's say B is latched and A is unlatched. This latching and unlatching is controlled by the insulated sections on the A and B legs. The third insulated section, on the common leg, would then tell the switch to throw in the direction indicated by the first relay, and reset the first relay to the next condition.

Sorry Tom, but a spring switch isn't going to work for this one, as there is no loop in the track plan. The shape is a "Y".

Big Jim posted:
Big_Boy_4005 posted:

 Sorry Tom, but a spring switch isn't going to work for this one, as there is no loop in the track plan. The shape is a "Y".

Sorry Big Boy 4005,
It will work exactly like Tom said! No electrics needed!!!

At least one of us doesn't understand the problem. A spring switch is always going to send the trolley on the same route. There is no way to make it alternate routes as the OP requested.

This is NOT a trailing point problem, this is a facing point problem, and a spring won't solve it.

I know what a spring switch is, and have a bunch of them on my layout, and they do what I want them to do, but this isn't it, unless I don't understand the problem. Tom's description of a spring switch is fine, but it is not the solution here.

Please read the original post again.

Rairoads used spring loaded switches for years,as well as trolley and traction companies.

This is something that can be made out of a manual switch and spring setup I'm sure.

The trailing point direction needs to be the reverse move,or the direction you run thru the switch.

Collin "The Eastern Kentucky & Ohio R.R."

mackb4 posted:

Rairoads used spring loaded switches for years,as well as trolley and traction companies.

This is something that can be made out of a manual switch and spring setup I'm sure.

The trailing point direction needs to be the reverse move,or the direction you run thru the switch.

Nope. How does the switch change directions in the facing point movement? This is the crux of the problem. It must be an electrically powered switch. Spring won't do.

I was a computer science major in college. If there was one thing I learned from that experience, it was the "Universal problem solving algorithm". It is very simple, and has just four steps:

  1. Understand the problem!
  2. Have an idea
  3. Make sure your idea solves the problem
  4. Implement your idea

So far, suggestions offered have mainly failed on step one, not entirely understanding the problem. 

Boilermaker1 posted:

Easiest solution, put the switch machine button on the bumper and let the trolley push it. 

Otherwise, I don’t see why you couldn’t rig up an isolated section of track to activate the the switch motor like an anti-derail would function.

This one actually made it to step three before running into trouble. How does the button know which way to throw the switch? A: You need a way to keep track of the current condition, then reset to the opposite at the end of each cycle.

If I seem a little passionate and perhaps defensive on this topic, it's because I have a good deal of experience dealing with relay logic to solve train movement problems like this one. To me this is a bit of a puzzle, one that I have never wanted to solve prior to this, but the gauntlet has been thrown.

I am not suggesting that mine is the only way to do this. However, of all the suggestions thus far, it's the only one that has solved the problem. I'm 99.9% sure this solution will work, as I have done a relay logic sequencing operation before, with a four track yard. This is just a two position task, as I explained in my first post here. 

I'll put pencil to paper and draw a schematic as proof of the solution. It might take a day or so.

Coming from an electrical background myself, I can see how latching a relay would work - but I think there's an all mechanical answer out there, though it would require custom parts and such. 

I keep thinking of marble runs - there's a device that does the motion we require, passes one direction, while setting itself for the opposite motion.

https://www.youtube.com/watch?v=oP1eIqCFhMo

Also one sprung switch wouldn't work, for the reasons listed.

But a Wye of sprung switches sends the trolley down both the legs in question - the problem here is, it doesn't go all the way to the top on one path.

Assume all switches are sprung to the right. The star indicates what I would normal consider the end of the line, from which the 2 routes diverge. As you can see, leaving from the bottom left, the trolley doesn't go to the star before heading to the start. 

 

EDIT

 

I think I got it. We mentioned putting a switch button on the COMMON bumper-

Instead, put switches on the end of routes A and B, and wire it so it sends power to flip the switch the opposite way.  Trolley goes down route A, hits bumper/switch, power sets switch for for route B. Trolley rolls though the switch, hits bumper and reverses, goes down route B. Repeat.

1200px-Wye.svg

Attachments

Photos (1)

The marble run was really cool, but I don't think it is applicable here. I also think you have the OP's track plan wrong. There's only one switch in the track, giving you three legs. Please correct me if I'm wrong, because everything I've said to this point is based on this track plan.

trolley

When the trolley gets to point C, you have to flip the switch the opposite direction. As I said earlier, you need to know where you came from. So when you reach A, you set the condition to B on the next throw. When you get to C, the switch throws routing you to B. When you get to B, you set the condition to A next, and arriving back at C completes the cycle. Repeat...

Attachments

Photos (1)

Yeah, I get it, and that trackplan makes sense to the OP. I think my terminology fowled my idea. 

 

To rephrase - Wire two buttons (electrical switches) at the bumpers at A & B, with wire all the way back to the turnout motor.

When the trolley hits point A, it will

1)change direction, running towards the turnout (switch)

2)Press the button (electrical switch), throwing the turnout (switch) toward route B

From there, the trolley heads towards C, running though the thrown turnout (switch) . After contacting the bumper at C, it reverses direction, and it will follow the turnout (switch) toward point B, where the opposite happens. Repeat.

Thanks Richard. 

Lucky, you can't throw the switch when the trolley is at A or B, because you still have to pass through it to get back to C, and once you get to C, it is thrown the way you last passed through, which means you go back to the leg you just left. Your method won't allow the trolley to use both routes. This fact demands that the throwing of the switch be triggered at C, so you need to keep track of where you came from, A or B. 

That's the way the event sequence has to go.

I gave a good deal of thought to a mechanical solution, but couldn't think of a good way to throw the switch. It's a lot easier to direct the electrons to do the job, than an actual physical force.

I'm still working on the electrical schematic for this, I'm very rusty with relay logic, as I haven't used it in many years. I'm in the middle of step three of the algorithm. Richard, you get to do step four, but I'll be able to talk you through it. 

BTW, I read the original post many times, and found it pretty clear, what the situation was. This is a tricky problem!

Logic dictates that the switch should be thrown when the trolley hits the common bumper (C in Big Boy 4005). That way the trolley would go to leg A and come back to hit the bumper at C. That would throw the switch so the trolley will then go B and so on. How to get the bumper powered to the switch is the question.

One component which may come into play for this specific application is a dual-coil latching relay.  That is, when the trolley enters the A path, the insulated rail triggers the "set" coil.  When the trolley enters the B path, the insulated rail triggers the "reset" coil.  The output of this relay is then used to select which switch machine is fired when the trolley is in the C path.

While latching relays are only a couple bucks they require soldering and such; when mounted on a module with screw-terminals the off-the-shelf versions are $10 or more.  One technique is to take advantage of the insanely low priced eBay relay modules and wire these non-latching relays into a latching configuration.  I show this in this OGR thread with a related though not the same application.

Here's a pic from that thread.  I believe you can do your specific application with the components shown below.  No soldering required!   One idea is to include a bypass switch to force the trolley to ONLY use the A or B path...rather than alternating A or B.

latching relay hack

Attachments

Photos (1)
stan2004 posted:

One component which may come into play for this specific application is a dual-coil latching relay.  That is, when the trolley enters the A path, the insulated rail triggers the "set" coil.  When the trolley enters the B path, the insulated rail triggers the "reset" coil.  The output of this relay is then used to select which switch machine is fired when the trolley is in the C path.

While latching relays are only a couple bucks they require soldering and such; when mounted on a module with screw-terminals the off-the-shelf versions are $10 or more.  One technique is to take advantage of the insanely low priced eBay relay modules and wire these non-latching relays into a latching configuration.  I show this in this OGR thread with a related though not the same application.

Here's a pic from that thread.  I believe you can do your specific application with the components shown below.  No soldering required!   One idea is to include a bypass switch to force the trolley to ONLY use the A or B path...rather than alternating A or B.

latching relay hack

Exactly! Thanks Stan, I was even thinking of that specific relay module and power supply for this.

Gentlemen, we have this same electrical requirement in modern pipe organ consoles where each stop key or knob has on and off solenoids built into it. A push button t will move the stop to the other position from what it currently is. Even if you manually move the stop, the logic senses what to do next time you press the button. The circuit boards (called “Reversibles”) (12v DC) are available. Check with your local pipe organ installer or service technician for sources.

Richard

Big_Boy_4005 posted:
stan2004 posted:

One component which may come into play for this specific application is a dual-coil latching relay.  That is, when the trolley enters the A path, the insulated rail triggers the "set" coil.  When the trolley enters the B path, the insulated rail triggers the "reset" coil.  The output of this relay is then used to select which switch machine is fired when the trolley is in the C path.

While latching relays are only a couple bucks they require soldering and such; when mounted on a module with screw-terminals the off-the-shelf versions are $10 or more.  One technique is to take advantage of the insanely low priced eBay relay modules and wire these non-latching relays into a latching configuration.  I show this in this OGR thread with a related though not the same application.

Here's a pic from that thread.  I believe you can do your specific application with the components shown below.  No soldering required!   One idea is to include a bypass switch to force the trolley to ONLY use the A or B path...rather than alternating A or B.

latching relay hack

Exactly! Thanks Stan, I was even thinking of that specific relay module and power supply for this.

I am sorry but I am a little confused. How does that relay alternate between A and B? Every time the trolley lands in C triggers the relay, I don't understand how to make it bounce between the two routes. If you can explain I would be grateful.

Mike

dual coil latching relay method

The trick is the "memory" function of a latching relay.  That is, you only need to momentarily trigger the relay to change its position and it remembers the new position even after removing the trigger (voltage).  In general a latching relay has a "set" input and a "reset" input.  In this example, when the trolley runs over the A insulated section, it sets the relay.  When the trolley runs over the B insulated section, it resets the relay.  When the trolley runs over the C insulated section, it applies power to the switch machine to toggle the direction.  That is, if the trolley last hit the A section, the relay will be set to apply the C trigger to change the switch to the B position.  If the trolley last hit the B section, the relay will be reset to apply the C trigger to change the switch to the A position.  That is how it alternates.

What's subtle is what Elliot described in one of his posts.  The latching relay is toggled when the trolley enters the A or B section.  You cannot have the relay toggle from the C section.  Why?  Because you can get multiple triggers from dirty track!

Attachments

Photos (1)

Stan, thanks for getting me off the the hook with that diagram. My brain was starting to hurt, and I was losing sleep. I knew it could be done. That latching relay really makes it look simple. Well worth a few extra bucks to do it that way. I had all the pieces of the puzzle.

Richard, yes, leave the insulating pins in the switch. Taking them out would cause the points to lock in one way or vibrate back and forth. Both bad. The switch in this application won't use the anti-derailing feature. The relay is doing the throwing, but they still need to be there. 

Richard Landreth posted:

 

...What gauge wire would be best to use?

Whatever wire gauge came with the switch and controller would work fine - probably AWG 24 or so.  Note that the "large" current only flows momentarily when the switch flips position.

But so I'm clear, which implementation are you thinking of?  You can buy a latching relay module off-the-shelf from, say, Azatrax for about $14 plus $8 shipping:

LARY-AC-photo-web

It has screw-terminals so you don't have to mess with soldering.  And their AC version directly handles AC coil voltage so you don't have to mess with DC.  But if, for example, the 10-15V operating voltage of the Azatrax latching relay is not suitable for however fast/slow you run your trolleys, then perhaps more assistance is in order.  If you're on top of all this, then you're on your way and I await to hear how it works out!

OTOH I'm the consummate cheap-skate and have been known to amuse myself fiddling with low-cost eBay free-shipping-from-Asia gadgets where you can get it done for closer to $5 though you have to mess around with more wiring.

 

 

Attachments

Photos (1)

I don't think control and turnout type were mentioned, I didn't read close after because I knew Elliot was right.  But depending on equipment, an old 2 position e-unit and switch "at C" would do it old school style. 

For reliability,  I'd skip isolated rail triggers, the low wheel count and light weight of bump and go makes it sketchy.  If the bumper option doesn't pan out (plenty of pressure; it already throws one switch... but mounting...?  The PW lighted bumpers light would always blink when hit, but I'm not sure if that was by design or pressure disconnect from track.. If by design, a relay on n.open,to add power to the e-unit for a flash would work. 

Otherwise a micro switch with a wire wisker throw arm would likely be my choice.    Whatever method, note the switch must be at the far end of C so it cannot be thrown twice, once before and after the "bounce".  However, mid run triggering between turnout and C could be done with a 3 position E-unit.

The e-unit itself is a mechanical latching vs electrical latching relay

"Still trying to not shoot my eye out"

 

"Nursing insomnia one railcar at a time"

My aroma therapy? Smoke Pellets.

 





Guitarmike posted:
Big_Boy_4005 posted:
stan2004 posted:

One component which may come into play for this specific application is a dual-coil latching relay.  That is, when the trolley enters the A path, the insulated rail triggers the "set" coil.  When the trolley enters the B path, the insulated rail triggers the "reset" coil.  The output of this relay is then used to select which switch machine is fired when the trolley is in the C path.

While latching relays are only a couple bucks they require soldering and such; when mounted on a module with screw-terminals the off-the-shelf versions are $10 or more.  One technique is to take advantage of the insanely low priced eBay relay modules and wire these non-latching relays into a latching configuration.  I show this in this OGR thread with a related though not the same application.

Here's a pic from that thread.  I believe you can do your specific application with the components shown below.  No soldering required!   One idea is to include a bypass switch to force the trolley to ONLY use the A or B path...rather than alternating A or B.

latching relay hack

Exactly! Thanks Stan, I was even thinking of that specific relay module and power supply for this.

I am sorry but I am a little confused. How does that relay alternate between A and B? Every time the trolley lands in C triggers the relay, I don't understand how to make it bounce between the two routes. If you can explain I would be grateful.

Mike, using that relay module, you could create your own latching relay by wiring them together in the correct way. That was where my rust was showing, and why my brain was hurting. I've done that before with standard relays, but I'm sure Stan has more practice and experience, and could draw it up in a couple minutes.

All the relay does, is keep track of which leg, A or B, you visited last. By doing that, when you get to C, you throw the switch the other way. The trigger at C is the insulated section, which routes that ground signal through the relay contacts to throw the switch the correct way. It is a very elegant solution! 

Wouldn't this be the same as using a single-throw double-pole (STDP) momentary-on push-button switch that could be mounted in the bumper?  The momentary-on is required to prevent burning out the coils of the switch machine unless you are using a switch motor that denergizes the coils when it moves.

Jan

Jan posted:

Wouldn't this be the same as using a single-throw double-pole (STDP) momentary-on push-button switch that could be mounted in the bumper?  The momentary-on is required to prevent burning out the coils of the switch machine unless you are using a switch motor that denergizes the coils when it moves.

Depends on what you mean by "this".  As I see it, the key component/function is the latching relay...or something equivalent that remembers which direction the switch should flip to next. 

But if you're referring to previous comments about the reliability of the insulated-rail method with lightweight trolleys, then sure, you could use momentary push-buttons mounted in each of the bumpers (A, B, and C).  The A and B push-buttons (or hand-built spring lever contacts) would momentarily trigger the set and reset coil inputs of the latching relay.  The C push-button would momentarily supply power to the "COM" output of the latching relay which steers that power to one of the two turnout solenoid mechanisms.

Stan2004, after looking more closely at the schematic, I started to get confused.  Sorry for being such a dummy, but electrical things are not my forte.

Quetions:

1. I see 3 12V lines coming from the delay module, but where do they end up and what are they since the delay module is not being used?

2. Where is the the ZWC connect? I see it in the description but not on the relay

3. A green wire is shown coming from the delay module and jumpering between A1 and A2 on the relay.How is it wired now that the delay module is not being used?

Where is the B1 wired and where does it go?

 

Are you intending to use the off-the-shelf latching relay module from Azatrax (or the like)… or cobble together the latching function  using a multi-relay non-latching eBay relay module as shown in my diagram?  I may have misunderstood you previous response but I thought you were going with the Azatrax method.

The diagram I showed with ZWC and so on was just a cut-and-paste from the other thread with a similar but not quite the same trolley configuration.  That version required delay modules and so on.  Your application is simpler and does not require delay modules.  I can draw up a diagram for your specific trolley application.   So, 

1. Which latching relay method are you planning to use?

2. What is your power source/transformer?

 

stan2004 posted:

Are you intending to use the off-the-shelf latching relay module from Azatrax (or the like)… or cobble together the latching function  using a multi-relay non-latching eBay relay module as shown in my diagram?  I may have misunderstood you previous response but I thought you were going with the Azatrax method.

The diagram I showed with ZWC and so on was just a cut-and-paste from the other thread with a similar but not quite the same trolley configuration.  That version required delay modules and so on.  Your application is simpler and does not require delay modules.  I can draw up a diagram for your specific trolley application.   So, 

1. Which latching relay method are you planning to use?

2. What is your power source/transformer?

 

Stan, are you Stan Roy who was featured in the McComas and Tuoy 6 video set, and who had the record for simultaneously running the most O Gauge trains (maybe 27)? 

I can't help but think that you are because of your knowledge about relays. Arnold

 

In my little world, I leave this troubled world behind.

This post was forked into a new topic here: A Multi-Train Running Record?
Arnold D. Cribari posted:

Stan, are you Stan Roy who was featured in the McComas and Tuoy 6 video set, and who had the record for simultaneously running the most O Gauge trains (maybe 27)? 

I can't help but think that you are because of your knowledge about relays. Arnold

 

An interesting question Arnold. You must then know that I once tried to challenge that record, if you remember volume 6. If you don't, watch it again.

Add Reply

Likes (2)
Post
OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
330-757-3020

www.ogaugerr.com
×
×
×
×
×