Spring points!

[Siberian Snooper]

Why not do what the diagram suggests? Use a light spring to hold the switch blades for the required route and let the train push through them, they will just spring back, when not held open by a flange.

 

 

[retbsignalman]

I have tried a number of options but none seem to be light enough to prevent derailment of lighter vehicles whilst having the strength to restore the normal route unfortunately.....

[Siberian Snooper]

Can You add some weight to the lighter vehicles?

 

 

[retbsignalman]

On 21/11/2023 at 07:37, Jeremy Cumberland said:

I've just edited my last post, thinking it more likely that the detector terminals C are a switched power output rather than a switched contact. Also, this is the "safer" way of wiring them. If they are a switched contact, then you won't do any damage wiring them as above (but the circuit won't do anything) whereas if they are a switched power out and you wire them as a switched contact, you risk doing some damage.

 

If the above circuit does not work, then wire the coil as follows:

"Set" circuit:

12V to left hand detector terminal C-

Left hand detector terminal C+ to relay terminal 13

Relay terminal 14 to common return.

 

Latching circuit:

12V to relay terminal 3

Relay terminal 7 to right hand detector terminal C-

Right hand detector terminal C+ to relay terminal 13.

Hi Jeremy, 

I've had a proper look at your description and come up with the attached diagram.....hopefully that matches your description! I've drawn it as per the relay terminals to help clarify. 

 

Looking at your alternative should that not work, I'm confused about the wiring in both the 'set' circuit and 'latching' circuit.

 

I'm using a pair of DCC Concepts Intelligent detectors btw.

 

Thanks in advance 

 

Graeme 

 

 

 

[Jeremy Cumberland]

That's right. Make sure that both wires going to 14 go the the C- terminal on the detector.

 

If the point motors the wrong way, swap over the wires to 1 and 2 (you can do this either at the relay or at the Tortoise).

[retbsignalman]

Thank you again Jeremy! I'll let you know how I get on  

 

Cheers Graeme 

[Nick C]

On 22/11/2023 at 07:58, retbsignalman said:

I have tried a number of options but none seem to be light enough to prevent derailment of lighter vehicles whilst having the strength to restore the normal route unfortunately.....

One I saw elsewhere on here was done with a bit of string and a weight hanging below the baseboard - looks like the photos were lost, but see @The Bigbee Line's Hayling island thread:

Quote

 

If you're using Peco points you'll need to remove the over-centre spring, then they'll move easily.

[retbsignalman]

On 21/11/2023 at 07:37, Jeremy Cumberland said:

If the above circuit does not work, then wire the coil as follows:

"Set" circuit:

12V to left hand detector terminal C-

Left hand detector terminal C+ to relay terminal 13

Relay terminal 14 to common return.

 

Latching circuit:

12V to relay terminal 3

Relay terminal 7 to right hand detector terminal C-

Right hand detector terminal C+ to relay terminal 13.

Good evening Jeremy, 

 

I've followed the initial diagram but when a loco occupies the "Set" circuit, the relay activates and the Tortoise has no supply, however when the loco occupies the Latching circuit and clears the "Set" circuit the Tortoise regains its supply and resets the point below the loco.

 

Unfortunately, I'm not sure how to relate the above description to a wiring diagram to help remedy the problem. All help gratefully received. Thanks in advance 

 

Graeme 

[Jeremy Cumberland]

I'm sorry to hear it doesn't work.

 

I think the detectors have LEDs on them. Are they in a position you can see? If you place a train on the right hand track circuit, does the LED light up? The train will need to draw power, which might mean driving it, but if it is DCC or has lighting, this should be enough. With the LED lit up, can you set the multimeter (if you have one) to DC volts and measure either between detector terminals C+ and C- or else between relay terminals 3 and 14. You should see 12 volts. This proves that the right hand detector works as intended. If the LED doesn't light up, or you don't get a 12V output, then there might be a problem with the detector, the power supply to terminals A or the connection at terminal C+ or C-.

 

The next test is to look at what the track circuits are actually doing when you drive a train over them. For this, it would help if you could disconnect the Tortoise from the points and just set the points manually for though running. Drive a train over the two track circuits and look at the LEDs on the two detectors. The circuit is designed around continuous detection, and I wonder if the right hand detector is dropping out before the train has fully passed. What you are looking for is the left hand detector LED lighting up, then both detector LEDs lighting up together, then the right hand detector LED remaining continuously lit till the train has passed the points. If the right hand detector LED goes out at any time when the left hand detector LED is not lit, the points will motor back.

 

One other thing you might do with a multimeter is measure the resistance between relay terminals 3 and 7. It would be a safe precaution to disconnect the wires from these terminals first. Set the multimeter to the lowest resistance setting and with no trains on the track, measure the resistance between pins 3 and 7. It should be infinite (which probably reads OL). Now place a train on the left hand track circuit and the resistance should change to very nearly zero. If you take the train off again, it should change back to infinite.

[roythebus1]

What a lot of talk to achieve very little! Going back to the ealry 1980s with The Model Railway Club's "New Annington" layout, we had entry/exit push buttons for the hidden loops. We extended the loops to add another 6 roads. The loops man set the road for an incoming train, a light activated switch detected when the train was in section and locked the road. When the leading vehicle hit a ramp in the track, power off, route reset itself. The light activated infra-red switch (no light-sensitive LEDS in those days that we could afford) was set at an angle across the track, so beam was broken as train passed. when it "saw" the reflector, it reset the points. all very well until one set in particular kept derailing, as the road kept resetting under the wagons.

 

Most rolling stock had short tension locks, exept the Lima ARC Roadstone hoppers with Lima couplings! The detector was seeing the reflector between the wagons, thinking "daylight, train is clear, change points! Rather than make everyone change their couplings which would have been ideal as the big gap between the Lima wagons looked awful, Mike Randall installed a Fulgurex or similar point motor in the circuit to act as a delay to the reset, train out of the way, circuit. If the Lima hoppers came by, the Fulgurex would whirr away to itself until the train was clear. Anything closer coupled and it wouldn't see daylight, so waited until the train had passed, Fulgurex whirred, and points reset.  A very simple way to insert a delay in an electrical circuit.

 

Why not just put a motor on your points, it's a lot easier.

[retbsignalman]

16 hours ago, Jeremy Cumberland said:

I'm sorry to hear it doesn't work.

 

I think the detectors have LEDs on them. Are they in a position you can see? If you place a train on the right hand track circuit, does the LED light up?

Good afternoon Jeremy 

 

Both LEDs illuminate as they should 

16 hours ago, Jeremy Cumberland said:

 

The train will need to draw power, which might mean driving it, but if it is DCC or has lighting, this should be enough. With the LED lit up, can you set the multimeter (if you have one) to DC volts and measure either between detector terminals C+ and C- or else between relay terminals 3 and 14. You should see 12 volts. This proves that the right hand detector works as intended.

The multimeter shows -11 between 3 and 14 

16 hours ago, Jeremy Cumberland said:

 

 

If the LED doesn't light up, or you don't get a 12V output, then there might be a problem with the detector, the power supply to terminals A or the connection at terminal C+ or C-.

 

The next test is to look at what the track circuits are actually doing when you drive a train over them. For this, it would help if you could disconnect the Tortoise from the points and just set the points manually for though running. Drive a train over the two track circuits and look at the LEDs on the two detectors. The circuit is designed around continuous detection, and I wonder if the right hand detector is dropping out before the train has fully passed. What you are looking for is the left hand detector LED lighting up, then both detector LEDs lighting up together, then the right hand detector LED remaining continuously lit till the train has passed the points. If the right hand detector LED goes out at any time when the left hand detector LED is not lit, the points will motor back.

As the loco occupies the left hand track circuit the relay activates, the red light on the detector illuminates but the power to the Tortoise is broken (the point doesn't change,  however I then manually move the mechanism).

When the loco occupies the right hand track circuit the red light on the detector illuminates, however when the loco has cleared the left hand track circuit completely the relay activates again and the Tortoise is powered up and returns to its original position (I have to hold the tie bar to prevent derailment).

 

Thanks Graeme 

16 hours ago, Jeremy Cumberland said:

 

 

[Jeremy Cumberland]

1 hour ago, retbsignalman said:

Both LEDs illuminate as they should 

That's good.

 

1 hour ago, retbsignalman said:

The multimeter shows -11 between 3 and 14 

That's fine, depending on which way round the multimeter wires are.

 

I don't quite understand your descriptions though.

 

With both track circuits initially unoccupied, if you place a train on the left hand track circuit, the detector LED should light up, the relay should energise (you might hear it click) and the Tortoise should motor across. If you now remove the train (pick it up off the track or drive it back to the left, still leaving the right hand track circuit unoccupied), the detector LED should go out, the relay should de-energise (again, you might hear it click) and the Tortoise should motor back the other way.

 

With a train on the left hand track circuit, could you measure the voltage across relay terminals 13 and 14. The voltage itself isn't important, but the sign (+ or -) is. Make a note of which probe (red or black) you use for terminal 14.

 

With both track circuits initially unoccupied, If you place a train on the right hand track circuit (leaving the left hand track circuit unoccupied), the detector LED should light up but the relay and Tortoise should not do anything. If the relay activates and the Tortoise motors, then there is a problem with the relay 3 to 7 contact. You could try using terminals 4 and 8 instead of 3 and 7, but if that doesn't work, some other investigation will be needed - go to A below.

 

With a train on the right track circuit (and the left hand track circuit unoccupied), could you measure the voltage across relay terminals 3 and 14. Use the same multimeter probe (black or red) for terminal 14 that you used the last time. You should see 11 volts, but again the voltage does not matter and it is the sign (+ or -) that is important. It should be the same as the reading across terminals 13 and 14 when the left hand track circuit was occupied. If it is the opposite of last time, swap the wires from the right hand detector to relay terminals 3 and 14.

 

If everything has worked as expected so far, then can you use two trains to occupy the two track circuits independently. Place a train on the left hand track circuit. The detector LED should light, the relay should energise and the Tortoise should motor across. Place the other train on the right hand track circuit. The detector LED should light, but nothing else should happen. Now remove the train from the left hand track circuit. The left hand detector LED should go out, but nothing else should happen. If the points now motor back, then there is a problem that needs investigating - go to A below. If the points remain set, then remove the train from the right hand track circuit. The relay should de-energise and points should now motor across. This means that the circuit is working as intended, but it looks like the right hand detector is momentarily losing detection of the train as it drives from left to right in normal operation. This probably means having to use some other means of operating the point, or finding a way to make the right hand track circuit more reliable.

 

A: This section checks the operation of the relay contacts. Leave the wires connected to terminals 1, 2, 5, 6, 9, 10, 13 and 14, but disconnect the wires from terminals 3 and 7. Place a train on the left hand track circuit. The relay should energise and the Tortoise should motor across. Set the multimeter to measure resistance (the lowest resistance setting is best) or continuity, and confirm that you can detect a short circuit by touching the probes together. You are now looking for a short circuit between any pair of unused terminals. There should be short circuits between terminals 3 and 7 and between 4 and 8, but it doesn't matter where you actually find a short circuit. When you have found a short, remove the train from the track circuit and check that these same terminals are now open circuit (the multimeter display should not change when you touch the probes on the terminals). Now connect the two removed wires (one from right hand detector terminal C+ and the other from relay terminal 14) to these two terminals. It does not matter which wire goes to which terminal.

 

I hope this makes sense.