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Discussion Starter #1
I would like to have my MPC era bascule bridge operate via insulated track sections, so that I don't have to open and close the bridge using the push button controller. This is the plastic bridge with the bridge tender house hanging on one side.

If I use only the insulated track a slow moving train does not cross over the insulated rail quickly enough, so what happens is the bridge raises and lowers or vice versa.

I have several activates that you sold me a couple of years ago. Can these be used in conjunction with an insulated rail to accomplish the operation I'm looking for ?

IMG_2826.jpg
IMG_2827.jpg
 

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Discussion Starter #3
I think I need more info. I don't get why the slow moving train is a problem.


As the train passes over the insulated section, the bridge raises or lowers, whichever the case may be. If the train does not leave the insulated section quickly enough, the bridge remains powered going through it's raise or lower sequence. Normally, the action is accomplished by the momentary press of the activation button.

Here's a picture of the bridge. Look behind the rocket launcher. You can see the tan abutments and the bridge tender shack.


IMG_2526.jpg
 

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Do you have an insulated track on both side of the bridge? That would insure that it stays down until the train completely passes the bridge (though a short loco completely on the bridge may be a problem). It may be possible to use a capacitor to create a delay in raising the bridge (though a large cap may be needed).
 

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Discussion Starter #5
Do you have an insulated track on both side of the bridge? That would insure that it stays down until the train completely passes the bridge (though a short loco completely on the bridge may be a problem). It may be possible to use a capacitor to create a delay in raising the bridge (though a large cap may be needed).
I have an insulated rail about seven feet on either side of the bridge. The first insulated section is about six feet before the bridge. This raises the span so the train can pass. Once the train has passed, there's another insulated section that is supposed to close the bridge. If I run, lets say a pair of RDCs, everything works according to Hoyle. But because a longer train remains on the insulated section all during the raising of the span, the lowering automatically starts.

Here's a partial track plan along with the complete plan.

IMG_2844.jpg
IMG_2847.jpg
IMG_2844.jpg
 

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I have an insulated rail about seven feet on either side of the bridge. The first insulated section is about six feet before the bridge. This raises the span so the train can pass. Once the train has passed, there's another insulated section that is supposed to close the bridge. If I run, lets say a pair of RDCs, everything works according to Hoyle. But because a longer train remains on the insulated section all during the raising of the span, the lowering automatically starts.
...
I'm reading your explanation as if the bridge's motor only spins one-way. Such that once the bridge is raised, continuing power to the motor and the bridge starts to lower - all controlled by the gearing.

Can that be right? Or is the train hits the following insulated rail thus lowering the bridge before the last cars is through?
 

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Discussion Starter #7
I'm reading your explanation as if the bridge's motor only spins one-way. Such that once the bridge is raised, continuing power to the motor and the bridge starts to lower - all controlled by the gearing.

Can that be right? Or is the train hits the following insulated rail thus lowering the bridge before the last cars is through?
You are correct Mike. If I were to hold my thumb on the activation button, the bridge would raise and lower and keep doing so until I let go. Then whatever position it was in when I took my thumb off the button, the bridge would continue moving until it stopped in the up or down position.

It's activation is similar to the 313 bridge. You only need to press the activation button for maybe two seconds, then let go and the bridge raises and automatically stops in the open position. Then when the activation button is pressed again, the bridge lowers and power is cut off to the motor once more.
 

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Can we still get these ? Do we contact John or Hennings trains ?
Oopps just looked Hennings is out of stock. would still like to get some....
 

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You need something like a single shot that briefly pushes the button (makes the contact) and then releases until the train leaves the insulated section and then resets. eBay has tons of single-shot modules that could be adapted to this application. Also, for this application, why seven feet of insulated rail? Why not just a short section?
 

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Discussion Starter #10
You need something like a single shot that briefly pushes the button (makes the contact) and then releases until the train leaves the insulated section and then resets. eBay has tons of single-shot modules that could be adapted to this application. Also, for this application, why seven feet of insulated rail? Why not just a short section?
John, It's not seven feet of insulated rail. The single section of "O" gauge track has an insulated rail and it is seven feet away from the bridge.

So should I type in "single shot" when looking for a switch ?
 

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You are correct Mike. If I were to hold my thumb on the activation button, the bridge would raise and lower and keep doing so until I let go. Then whatever position it was in when I took my thumb off the button, the bridge would continue moving until it stopped in the up or down position.

It's activation is similar to the 313 bridge. You only need to press the activation button for maybe two seconds, then let go and the bridge raises and automatically stops in the open position. Then when the activation button is pressed again, the bridge lowers and power is cut off to the motor once more.
The way I see it you have two problems: (1) A long train on the leading insulated section causes the bridge to start the up cycle after it completes the down cycle; and (2) If you run a train longer than 7', the end of the train is still on the bridge when it's loco hits the training insulated section raising the bridge too early. The second problem can be caured by moving the insulated section further away then the longest train you plan to run (or a detection mechanism for a train still on the bridge)

For the first problem (your original post), John is right. You need a single shot trigger. And that problem is synonymous with the issue of my Marx switches. That is: if a long train passes the insulated section throwing the switch to the correct position for self tending operation (e.g., non derailing feature) then the switch's coil gets power for too long causing the coil to overheat or burnout. This is exasperated by a train parked (or derailed) on the insulated section. After a lot of thought, I came up with a solution for this problem: an adjustable one-shot trigger activated by the insulated section. I created it by using two Arduino modules and a resistor and capacitor. The Arduino modules are a AC-DC voltage regulator and an adjustable delay relay module (~$5 total).

When the train hits the insulated section, the connection to ground is sent to the switch coil (or your bridge) and the delay relay module powering up the system. While the train is on the insulated section, it continues to power the coil (or bridge) and the delay relay module. That causes the relay's time delay to expire thus triggering the relay to the normally open position and breaking the connection from accessory power to the switch coil (or you bridge). As long as the train is on the insulated section, the Arduino modules continue to get power via the insulated section's connection to ground. Thus the relay stays in the triggered NO position. So the switch coil (or the bridge) only gets power for the length of the adjustable time delay. I have the delay set for ~1 sec. You can see this action in the video, below. Look to the modules on the switch in the right foreground at the 30 and 53 sec marks. On the delay relay module, the first LED lights when the system is powered up via the insulated section. The second LED lights when the time has elapsed breaking power to the switch coil.

In the first diagram, the system is set for both the through and diverging routes. It can be adapted and simplified for the bridge's single trigger - the second diagram.


554818




554821
 

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Discussion Starter #13
The way I see it you have two problems: (1) A long train on the leading insulated section causes the bridge to start the up cycle after it completes the down cycle; and (2) If you run a train longer than 7', the end of the train is still on the bridge when it's loco hits the training insulated section raising the bridge too early. The second problem can be caured by moving the insulated section further away then the longest train you plan to run (or a detection mechanism for a train still on the bridge)

For the first problem (your original post), John is right. You need a single shot trigger. And that problem is synonymous with the issue of my Marx switches. That is: if a long train passes the insulated section throwing the switch to the correct position for self tending operation (e.g., non derailing feature) then the switch's coil gets power for too long causing the coil to overheat or burnout. This is exasperated by a train parked (or derailed) on the insulated section. After a lot of thought, I came up with a solution for this problem: an adjustable one-shot trigger activated by the insulated section. I created it by using two Arduino modules and a resistor and capacitor. The Arduino modules are a AC-DC voltage regulator and an adjustable delay relay module (~$5 total).

When the train hits the insulated section, the connection to ground is sent to the switch coil (or your bridge) and the delay relay module powering up the system. While the train is on the insulated section, it continues to power the coil (or bridge) and the delay relay module. That causes the relay's time delay to expire thus triggering the relay to the normally open position and breaking the connection from accessory power to the switch coil (or you bridge). As long as the train is on the insulated section, the Arduino modules continue to get power via the insulated section's connection to ground. Thus the relay stays in the triggered NO position. So the switch coil (or the bridge) only gets power for the length of the adjustable time delay. I have the delay set for ~1 sec. You can see this action in the video, below. Look to the modules on the switch in the right foreground at the 30 and 53 sec marks. On the delay relay module, the first LED lights when the system is powered up via the insulated section. The second LED lights when the time has elapsed breaking power to the switch coil.

In the first diagram, the system is set for both the through and diverging routes. It can be adapted and simplified for the bridge's single trigger - the second diagram.


View attachment 554818



View attachment 554821

Interesting, Mike. Being electronically challenged I would like to ask why the 12 V Linear Regulator is needed ? Then you have some other parts, the R510 and 10uF pieces. I know they are some sort of electronic parts, but don't really know what they do.

I found this on Evilbay just now. I wonder if I am on the right track ?


Here's another one

 

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maybe us a delay and/or a sensor on each side of the bridge. anything near the bridge will deactivate it. Does this help or am I missing something....
 

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Interesting, Mike. Being electronically challenged I would like to ask why the 12 V Linear Regulator is needed ? Then you have some other parts, the R510 and 10uF pieces. I know they are some sort of electronic parts, but don't really know what they do.
The regulator is needed unless you can guarantee you never exceed 12V (and also noted 12V DC) into the electronic relay module.
Also note that regulator shows AC input and DC output so it's NOT just a regulator, it's a rectifier from AC to DC.
Your transformer is putting out AC, the track sensing is thus AC, and worse, there are conditions where it could fluctuate voltage.
The resistor is just there as a load to drain the circuit when the sensing track section is open. A piece of your issue is controlling the timing AFTER a wheel passes. The regulator circuit likely has some capacitance and thus would tend to stay on and decay voltage after the last wheel crosses the sensing section.
I'm thinking the capacitor across the AC accessory voltage and track is there - well, I'm not sure, as a snubber or way to ensure TMCC signal is on the rail?

I didn't draw the diagram, just following the technical discussion myself as a learning point. I learn by also reading people's problems, trying to research the solution, and reading and understanding what others are doing.
 

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FWIW, I've actually purchased and used time delay relays modules for our club's use on accessories. We had a problem where certain accessories either needed short one shot timing and others that needed longer minimum duration timing in order to not get stuck or malfunction. By putting the relay modules in between the user buttons or track sensing sections, we can eliminate malfunctions of certain time cycle based accessories.

Fundamental point- knowing what module you buy, what it's requirements are (inputs and main power). And example here is one with a micro controller needs constant logic power to run the electronics. Some have built in regulators, some have even AC input capability, you have to know again, what it needed given you have an AC power source, and your sensing track section could also be AC, so it kind of matters. Then there are other super simple time delay modules with cheaper and less complex circuitry with no microprocessor, and so they can just be a power on and a set delay with a variable potentiometer to set the delay. The key is, they still need AC to DC conversion, and still have a limited input voltage, so hence the extra external AC to DC conversion and voltage regulation.

If you know what you are doing- sure, buying the cheapest possible time delay relay, buying or building the AC to DC and voltage regulator can save you money, but has prerequisite required knowledge.

Personally, I prefer the microprocessor based ones when I need an accurate fixed timed output or special sequencing, and as such, it likely has a regulator onboard, and as many inputs or outputs as needed, and being a microprocessor, can even do special functions, lockouts, and interlocks as required by your needs. Again, key here, if it has the LED display, buttons for programming, then read the details, it likely needs constant power and thus the wiring is completely different and may require a voltage regulator, or AC to DC conversion. Going even further, will the sensing inputs handle AC track voltage? All the kind of things you have to know and work out before buying- let alone wiring one up.

As an example from Amazon, a 2 input module since if I understand it correctly, you need 2 different possible inputs? I'm not saying this is the ideal module, just an example of what is out there. https://www.amazon.com/NOYITO-Progr...me+delay+relay+2+input&qid=1613946897&sr=8-40
 

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Interesting, Mike. Being electronically challenged I would like to ask why the 12 V Linear Regulator is needed ? Then you have some other parts, the R510 and 10uF pieces. I know they are some sort of electronic parts, but don't really know what they do.
...
The 12 V regulator module: First, it has a full wave bridge to turn the AC transformer voltage into DC required by it's regulator and the relay module. Second, it uses a linear regulator because buck regulators take a sec or two to come up to the correct voltage. I need instantaneous response with a fast passenger train and a single insulated track section just before the switch. Third, the delay module uses a relay with a 12 V DC coil that's powered directly from the inputs. So you need rectification and regulation to feed it. Note the module has a 5 V SMD regulator on board to power the logic on the relay module from the 12 V DC input.

The capacitor: This is the denounce circuit and incorrectly shown in the modified bridge diagram (removed stuff from the original too fast this morning - an easy fix). Should the train momentarily lose contact with the insulated rail (fast trains again), the capacitor holds over the connection thus avoiding a system reset while in use. I had this problem with a Marx 0-4-2 loco with a single traction tire on one of the drive wheels - only one drive wheel on one side to connect the insulated section.

The resistor: This insures the voltage in the system quickly goes to zero once the train has passed to reset the system. Without it, the electronics (the timing circuit) draw little power and the delay relay module doesn't reset quickly for the next train pass.

Here's a close up pic of the switch module. I piggybacked to the regulator and delay relay modules with double sided tape to make it compact. And the connections between the two modules are very short wires between their screw down terminals including the resistor.

Delay Relay.jpg
 

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Discussion Starter #18
The 12 V regulator module: First, it has a full wave bridge to turn the AC transformer voltage into DC required by it's regulator and the relay module. Second, it uses a linear regulator because buck regulators take a sec or two to come up to the correct voltage. I need instantaneous response with a fast passenger train and a single insulated track section just before the switch. Third, the delay module uses a relay with a 12 V DC coil that's powered directly from the inputs. So you need rectification and regulation to feed it. Note the module has a 5 V SMD regulator on board to power the logic on the relay module from the 12 V DC input.

The capacitor: This is the denounce circuit and incorrectly shown in the modified bridge diagram (removed stuff from the original too fast this morning - an easy fix). Should the train momentarily lose contact with the insulated rail (fast trains again), the capacitor holds over the connection thus avoiding a system reset while in use. I had this problem with a Marx 0-4-2 loco with a single traction tire on one of the drive wheels - only one drive wheel on one side to connect the insulated section.

The resistor: This insures the voltage in the system quickly goes to zero once the train has passed to reset the system. Without it, the electronics (the timing circuit) draw little power and the delay relay module doesn't reset quickly for the next train pass.

Here's a close up pic of the switch module. I piggybacked to the regulator and delay relay modules with double sided tape to make it compact. And the connections between the two modules are very short wires between their screw down terminals including the resistor.

View attachment 554851
Mike, thank you for sticking with me on this topic. Your knowledge is being absorbed, albeit slowly. It may be some time before we have total penetration.....LOL

I have used R/C mini modules for my large scale trains. The power input is isolated from the circuit I am controlling. Are the modules you are showing similar in that manner ? For instance, in this boxcar I used a module that had more than one function. I can open the doors and make the man push the crates out with two separate buttons on the transmitter. But the batteries that supply power to the receiver do not power the movements.

 

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Mike, thank you for sticking with me on this topic. Your knowledge is being absorbed, albeit slowly. It may be some time before we have total penetration.....LOL

I have used R/C mini modules for my large scale trains. The power input is isolated from the circuit I am controlling. Are the modules you are showing similar in that manner ? For instance, in this boxcar I used a module that had more than one function. I can open the doors and make the man push the crates out with two separate buttons on the transmitter. But the batteries that supply power to the receiver do not power the movements.

I may have some of the modules your using. They use the same radio technology as car key fob remotes. Obviously the transmitter being wireless is isolated. As are the receivers given they have their own batteries. It's the receiver module's relay that simply connects track power to the boxcar solenoids to activate the door or the guy. Since the relay's contacts are isolated from its trigger coil the system's control and power connections are isolated.

A little different but the same with the bridge ... Your using the transformer voltages to power the relay system, the bridge, and the bridge control - at the very least with a common ground. That's not an issue. Nor is the relay output connection to the bridge's "switch input". Although the module's electronics are not isolated from ground/transformer, it's relay contacts are. So the relay's contacts mimic a stand-alone push button switch. That allows those contacts to wired in parallel with the manual switch.
 

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Discussion Starter #20
The way I see it you have two problems: (1) A long train on the leading insulated section causes the bridge to start the up cycle after it completes the down cycle; and (2) If you run a train longer than 7', the end of the train is still on the bridge when it's loco hits the training insulated section raising the bridge too early. The second problem can be caured by moving the insulated section further away then the longest train you plan to run (or a detection mechanism for a train still on the bridge)

For the first problem (your original post), John is right. You need a single shot trigger. And that problem is synonymous with the issue of my Marx switches. That is: if a long train passes the insulated section throwing the switch to the correct position for self tending operation (e.g., non derailing feature) then the switch's coil gets power for too long causing the coil to overheat or burnout. This is exasperated by a train parked (or derailed) on the insulated section. After a lot of thought, I came up with a solution for this problem: an adjustable one-shot trigger activated by the insulated section. I created it by using two Arduino modules and a resistor and capacitor. The Arduino modules are a AC-DC voltage regulator and an adjustable delay relay module (~$5 total).

When the train hits the insulated section, the connection to ground is sent to the switch coil (or your bridge) and the delay relay module powering up the system. While the train is on the insulated section, it continues to power the coil (or bridge) and the delay relay module. That causes the relay's time delay to expire thus triggering the relay to the normally open position and breaking the connection from accessory power to the switch coil (or you bridge). As long as the train is on the insulated section, the Arduino modules continue to get power via the insulated section's connection to ground. Thus the relay stays in the triggered NO position. So the switch coil (or the bridge) only gets power for the length of the adjustable time delay. I have the delay set for ~1 sec. You can see this action in the video, below. Look to the modules on the switch in the right foreground at the 30 and 53 sec marks. On the delay relay module, the first LED lights when the system is powered up via the insulated section. The second LED lights when the time has elapsed breaking power to the switch coil.

In the first diagram, the system is set for both the through and diverging routes. It can be adapted and simplified for the bridge's single trigger - the second diagram.


View attachment 554818



View attachment 554821

Mike, in looking over your wiring diagram for the bridge, second diagram, you have the bridge inputs wired to the NC contacts. Shouldn't they be wired to the NO contacts ?
 
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