It doesn't matter that it's DC powered, the fact remains that it's an AC motor without permanent magnets for the stator.
As for your idea, I don't know that there's a canned solution, but pretty much any functionality can be created.
gunrunnerjohn posted:It doesn't matter that it's DC powered, the fact remains that it's an AC motor without permanent magnets for the stator.
As for your idea, I don't know that there's a canned solution, but pretty much any functionality can be created.
Just as a note, that the trolley in question in this thread is not the Pulllmor trolley we discussed in another thread. This thread is a current production Lionel Birney trolley which accepts AC or DC. The motor is DC. I know it's confusing: sorry.
I was thinking there may be a canned solution. Isn't this what "station stop" modules do? Maybe I just need one that's voltage triggered similar to the ones triggered by insulated rails. The module is triggered by the bump, stops for X time and than restarts. A diode on the trigger input could sense the + or - DC reverse change at bump depending on diode polarity.
You might look a something like the Z-Stuff DZ-1220 Trolley Control System. It has stops and also does audio, a neat addition. That might solve some of the issues you have.
1. Does the trolley have this problem in both directions? In other words at the "other" end of the line does it reverse direction using a similar setup?
2. Do you have ready access to the 2 DC motor wires BEFORE it goes into the bump reversal switch? I believe it's just a DPDT slide switches set up in the familiar polarity reversal configuration.
3. What's the voltage on the track? You mentioned something about other electronics (traffic lights?) running too. Is that all on the same track voltage? In other words is it stable DC, AC, or what?
4. Do you really want to spend $50 or more for a typical trolley-station-stop system that several companies sell? I realize there's value to plug-and-play, no-soldering-required...but I'm thinking more along the lines of few bucks of parts and some DIY, fire-up-the-soldering-iron approach.
gunrunnerjohn posted:You might look a something like the Z-Stuff DZ-1220 Trolley Control System. It has stops and also does audio, a neat addition. That might solve some of the issues you have.
Thanks, I've looked at that. My setup is more complicated, it's 3 lanes sync'd to traffic lights.
stan2004 posted:1. Does the trolley have this problem in both directions? In other words at the "other" end of the line does it reverse direction using a similar setup?
2. Do you have ready access to the 2 DC motor wires BEFORE it goes into the bump reversal switch? I believe it's just a DPDT slide switches set up in the familiar polarity reversal configuration.
3. What's the voltage on the track? You mentioned something about other electronics (traffic lights?) running too. Is that all on the same track voltage? In other words is it stable DC, AC, or what?
4. Do you really want to spend $50 or more for a typical trolley-station-stop system that several companies sell? I realize there's value to plug-and-play, no-soldering-required...but I'm thinking more along the lines of few bucks of parts and some DIY, fire-up-the-soldering-iron approach.
1) Good question, No the other side works perfectly. It uses current sensing to detect when the trolley is on the longer run and some logic to stop it on the insulated section after the trolley has reversed.
2) I presume so, since the reversing switch is in the trolley.
3) The controls and traffic lights are 12 VDC. Motive power for the 3 trolley lanes are going to be each independent variable TIU channels. Input power to the 3 TIU channels is a single Z1000 using the 14 VAC tap.
4) I'm not aware there is any manufacture that makes a trolley-station-stop that sync's three lanes to a 4 way stop traffic lights with collision avoidance. At least I couldn't fine one. I did use the Galak traffic light controller as a starting point with MTH traffic lights. I didn't use the MTH controller. I built my own interface between the Galak controller, the lights, the MRD1 and Dallee current detectors. Works pretty good except for this one glitch.
shorling posted:stan2004 posted:1. Does the trolley have this problem in both directions? In other words at the "other" end of the line does it reverse direction using a similar setup?
...1) Good question, No the other side works perfectly. It uses current sensing to detect when the trolley is on the longer run and some logic to stop it on the insulated section after the trolley has reversed.
..
What I'm getting at is perhaps a bit subtle. I'm thinking of a circuit that detects when the voltage is reversed across the DC motor terminals. But this reversal happens at each end of the line. So this means a circuit that detects reversal (+ to - OR - to +) will interrupt power on each end of the line even if not required on one end. It may indeed be benign to interrupt on the side that already has a working mechanism for stopping?
In other words I'm trying to determine if the circuit should only detect changes and take action when the motor voltage goes from + to - (and ignore - to + reversals which aren't a problem at the other end of the line).
stan2004 posted:shorling posted:stan2004 posted:1. Does the trolley have this problem in both directions? In other words at the "other" end of the line does it reverse direction using a similar setup?
...1) Good question, No the other side works perfectly. It uses current sensing to detect when the trolley is on the longer run and some logic to stop it on the insulated section after the trolley has reversed.
..What I'm getting at is perhaps a bit subtle. I'm thinking of a circuit that detects when the voltage is reversed across the DC motor terminals. But this reversal happens at each end of the line. So this means a circuit that detects reversal (+ to - OR - to +) will interrupt power on each end of the line even if not required on one end. It may indeed be benign to interrupt on the side that already has a working mechanism for stopping?In other words I'm trying to determine if the circuit should only detect changes and take action when the motor voltage goes from + to - (and ignore - to + reversals which aren't a problem at the other end of the line).
Only in one direction. l'll have to make sure the trolley is pointed in the direction to match the logic. I'm picturing a diode in series's with the coil of a DPDT relay which can be made to latch. A timer interrupts the latch. The key here is circuit speed., bump and the relay kicks in landing the trolley over the IR sensors defeating the MRD1 delay. The timer needs to be longer than the delay.
I received the 63 ms MRD1's the other day. I installed one today. Difficult swap out due to location, the fact that I'm not a spring chicken anymore and I only have two hands. SOLVED THE PROBLEM !!! Trolley stops at the bump fence and over the sensors. Two more to install.
