Tortoise 16v AC circuit problems

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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Fri Mar 10, 2023 10:58 pm

Julian Roberts wrote:
Martin Wynne wrote:Hi Julian,

You are reading the numbers off the top black scale? Ignore that, it is for measuring resistance.

Read the numbers corresponding to the switch setting. So when on 50 v the scale is 0-10-20-30-40-50.

From which the meter is showing 7 volts in your photo.

You wrote " orange - grey = ? No needle movement". Is that correct? It conflicts with what you said in your previous answer to my questions. Maybe you had the probes the opposite way round?

cheers,

Martin.



Hi Martin

Yes you're right I was reading the number at the top - hopefully Keith will see this.


I've just seen your previous post so I will answer that first


Yes Martin with red probe on orange and black probe on grey the reading is...apologies....I'm writing all this on my phone, very slow



20230310_225731.jpg
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Last edited by Julian Roberts on Fri Mar 10, 2023 11:03 pm, edited 1 time in total.

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Martin Wynne
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Re: Tortoise 16v AC circuit problems

Postby Martin Wynne » Fri Mar 10, 2023 11:02 pm

Hi Julian,

If the bulb is glowing bright both times that proves the power supply is working ok.

So there must be something wrong elsewhere. In the wiring to the switches or the motors, or maybe one of the switches is faulty, or one of the motors. Are you using the built in switches in the motors to change the crossing polarity on the track? Is there any possibility of a stray connection to the track wiring?

The only solution now is to disconnect everything and reconnect it one thing at a time until something stops working. It's now 11pm, so probably better to wait until tomorrow. But you could try completely disconnecting all of the motors except one, and checking that the one left works normally.

cheers,

Martin.
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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sat Mar 11, 2023 12:08 am

Hi Martin

Thanks .... the starting point was that one turnout on its own works fine in each direction but as soon another one is added the problem arises. Pretty sure it doesn't matter which pair of turnouts one tries the same happens but can check absolutely systematically tomorrow. Yes the crossings are wired to the internal switches. The second internal switch is not needed so it's not wired up. The track all runs perfectly so nothing to indicate a stray connection.

I've tested the microswitches and they seem to work correctly as far as I can tell.

What was noticeable with any pair of turnouts was that with the two blue wires connected up and the two yellow ones but only one grey, the fully connected turnout worked fine, it was connecting the grey to the other one that made the first run slowly in the return movement. So here ( as they are nearest for sound but you have to listen carefully) are 3 and 2:




3 is fully connected while 2 has the grey wire not connected. Then I connect its grey wire at about 20 secs (off camera) into the grey terminal and we have the problem on 3. Both have to be thrown, then the first return movement (irrespective of which turnout) is at proper speed, the second is at half speed.

Enough for now!

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Re: Tortoise 16v AC circuit problems

Postby Winander » Sat Mar 11, 2023 1:00 am

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This is what you should see:

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[color=#FF0000]Colours[/color] of your text:
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Martin Wynne
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Re: Tortoise 16v AC circuit problems

Postby Martin Wynne » Sat Mar 11, 2023 2:09 am

Julian Roberts wrote:3 is fully connected while 2 has the grey wire not connected. Then I connect its grey wire at about 20 secs (off camera) into the grey terminal and we have the problem on 3. Both have to be thrown, then the first return movement (irrespective of which turnout) is at proper speed, the second is at half speed.

Hi Julian,

You are doing too many things at once! You never will find the problem if you go on like that. ONE THING AT A TIME! :)

1. Get one motor working. By itself with nothing else connected. Does it run at the proper speed both ways? If it does, make all the same voltage measurements as before, 4 TIMES. Once while the motor is in one position. Once while it is in the other position. Once while it is moving forward. Once while it is moving back. Make a chart and write them all down.

2. Completely disconnect that motor and connect another one by itself. Repeat all of the above, 4 times again.

3. Repeat the process with all the other motors, each one connected by itself only.

4. Compare the results. It's possible that one motor will be different from the others, in which case you have probably found the problem.

5. If the results from all the motors are the same, we will need to go deeper, measuring the drawn currents with the motors connected in various combinations. But first double check yet again that the wiring matches the diagram exactly, with no stray strands of wire touching any other connection.

p.s. which wire is the blue wire? there is no blue wire in your diagram.

cheers,

Martin.
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Re: Tortoise 16v AC circuit problems

Postby Alan Turner » Sat Mar 11, 2023 9:54 am

The Tortoise will run slower using the AC option compared with the same voltage of DC because you are effectively using only half the AC voltage. So if you are using 16v AC it will run at the same speed as using 8v DC. However that's not the issue.

First I would instil some tidiness into the switching arrangements so at least the logic of current flow will be obvious.

Are you sure you have correctly identified the common on the micro-switch(?) and are you taking that to the motor with the feed on one of the other connections of the switch?

Then I would get one motor working as required and then add another until they all work or you find the point when they don't. You can. at that point, work out what's wrong.

regards

Alan

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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sat Mar 11, 2023 11:00 am

Very many thanks all. I can't get back to this for an hour or two yet, but, Martin, when you say

Get one motor working. By itself with nothing else connected.


do you mean I should disconnect the three wires for the internal (frog) switch too? - on each motor I test separately?

ps the blue wire is on the diagram, it's the one that goes to each motor individually from each switch.

Alan - the common on the actual switch is the top one, but the middle one on the drawing. Confirmed in conversation the other evening with some electrical experts.

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Martin Wynne
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Re: Tortoise 16v AC circuit problems

Postby Martin Wynne » Sat Mar 11, 2023 12:11 pm

Julian Roberts wrote:do you mean I should disconnect the three wires for the internal (frog) switch too? - on each motor I test separately?

ps the blue wire is on the diagram, it's the one that goes to each motor individually from each switch.

Alan - the common on the actual switch is the top one, but the middle one on the drawing. Confirmed in conversation the other evening with some electrical experts.

Hi Julian,

Yes, disconnect every single thing. Otherwise how can you find the fault? For example the motor terminals might have got mixed up and the track switching might be connected to the wrong ones.

the common on the actual switch is the top one, but the middle one on the drawing. Confirmed in conversation the other evening with some electrical experts.


Whoa! Did these "electrical experts" actually SEE the switches? Are these experrts not able to help you find the problem? If you have got the switch terminals mixed up it could explain everything. What does "top one" mean? It depends which way up the switch is installed.

p.s. as Alan explained, the motors in this circuit are running on half-wave, which means they will be slower than when Tortoise motors are run on DC, but they should always be the same slow speed.

cheers,

Martin.
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Tony Wilkins
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Re: Tortoise 16v AC circuit problems

Postby Tony Wilkins » Sat Mar 11, 2023 1:07 pm

Hi Julian.
With regard to the micro switches, how are the terminals actually marked? I know what I would expect to see, but I would rather you tell us.
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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sat Mar 11, 2023 2:14 pm

Hi Martin and Tony

Here is the microswitch, marked NC NO C. By "top" I mean as it sits in the S4 Soc lever frame, so that's the C terminal.

20230311_135012.jpg


20230311_135355.jpg


I took the microswitch to the club for that confirmation.

Cheers
Julian

ps of course there's any number of dumb things I may have done wrong! this being one of them, but I have asked about this particular issue before this online conversation
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Martin Wynne
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Re: Tortoise 16v AC circuit problems

Postby Martin Wynne » Sat Mar 11, 2023 3:31 pm

Hi Julian,

C is the correct common connection and should be connected to the motor (blue wire).

You seem to have got that right, so we are no further forward.

I think it needs someone to look at your installation. Can you get one of your friends from the club to come and check it for you?

Running the Tortoise motors on half-wave is a bit of a kludge from the start. It should work, but a proper triple-rail DC supply would be better. You could improvise that for testing with a couple of 9-volt or 12-volt batteries.

cheers,

Martin.
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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sat Mar 11, 2023 5:57 pm

Hi Martin

Well, either to take the layout to a friend or bring one here was Plan A, and my OP was not in the expectation of any detailed help, rather, to ask if anyone had had similar problems.

For what it's worth, I've got one more turnout motor installed that is a catch point so has no crossing. As this is not controlled by the Yard frame it's not connected in any way. And I've got one more motor that till now was not even wired up. I've connected them both up** to the lever frame, and the same thing happens - with just one connected it works fine, connect both up and the 2nd runs slow, reverse one and it runs normally, reverse the other and it runs slow. So if there's any mistake of mine it must be in the wiring between diodes and motors.

Yes, one of the experts at the club says the same thing about the AC circuit being a kludge. He uses a DC drive for his Tortoises with a relay for each. The AC circuit appealed (past tense!) to me on the grounds of simplicity. However Daves Bradwell and Holt use this method which is a pretty good recommendation.

Could I say that there is no problem as far as running trains is concerned - everything works completely as it should. I took the layout last Sunday to the "Starters Group" near Edinburgh, and all worked fine. The videos will probably link to test runs of locos. I don't care in the least if the turnout motors run slow some of the time.

May I thank you very much for your patience, and the instructions on using the meter. And to everyone who has made helpful suggestions.

Cheers
Julian

**Edit - ONE AT A TIME!!

Alan Turner
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Re: Tortoise 16v AC circuit problems

Postby Alan Turner » Sun Mar 12, 2023 9:35 am

Could I suggest you start again?

Remove all your existing wiring except for the wires going from the "C" tab on your Microswitches to one terminal of your Tortoise motors.

Then:

with a single strand of wire connect all "NC" tabs together. At the end of this wire solder a Diode to it.

with a single strand of wire connect all "NO" tabs together. At the end of this wire solder a Diode to it but make sure it is the opposite way to the diode that you used for the "NC" tabs.

Join the free ends of the diodes together and connect this to a terminal on your transformer.

Join the remaining transformer terminal to one motor terminal on every Tortoise motor, looping from motor to motor.

Finally connect the "C" terminals to the remaining motor terminal of the motor that you want that switch to control.

If you want two Tortoises to work from one switch those Tortoises need to be wired together in parallel.

regards

Alan

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Re: Tortoise 16v AC circuit problems

Postby davebradwell » Sun Mar 12, 2023 9:50 am

Alan, I would comment that Julian's problem is most likely a dud joint and that your practical suggestion does not specify how 2 diodes can be connected soundly to a wire - it needs a solder tag or similar. No more blobs. Will the thick diode wires fit through the tag on the microswitch with a wire, too?

DaveB

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Martin Wynne
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Re: Tortoise 16v AC circuit problems

Postby Martin Wynne » Sun Mar 12, 2023 10:48 am

Alan Turner wrote:with a single strand of wire connect all "NC" tabs together.....with a single strand of wire connect all "NO" tabs together.

Hi Julian, Alan,

Just to add that when you:

Join the remaining transformer terminal to one motor terminal on every Tortoise motor, looping from motor to motor.

you may need to swap the motor connections if necessary to cause each motor to lie Normal in the required direction.

Looping from one motor to the next might not be the best way to arrange the wires. A separate wire from each motor to a bus connection would make it easier to get them all the right way round if you don't get it right first time.

cheers,

Martin.
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Martin Wynne
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Re: Tortoise 16v AC circuit problems

Postby Martin Wynne » Sun Mar 12, 2023 11:00 am

davebradwell wrote:Alan, I would comment that Julian's problem is most likely a dud joint and that your practical suggestion does not specify how 2 diodes can be connected soundly to a wire - it needs a solder tag or similar. No more blobs. Will the thick diode wires fit through the tag on the microswitch with a wire, too?

Also, the components most likely to fail in this circuit are the diodes. Having them hidden in the gubbins of the lever frame might not be a good idea. Sod's law applies at all times. The simplest solution for Julian would be 2 screw choc-blocs with the diodes linked across between them. That also avoids any soldering or bending to the diode wires.

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Re: Tortoise 16v AC circuit problems

Postby davebradwell » Sun Mar 12, 2023 11:34 am

...and there I was trying to get rid of the screwed connections! Never mind! How about a compromise - where wires to be connected are twisted together then put in a clamp, a bit like house wiring.

The situation looks quite simple - a stalled motor draws more current than 3 motors running and owing to a fault (probably a high resistance joint) is pulling down the volts. The effect is symmetrical so fault likely to be in common return line. We can then move on to whether the stalled motor should draw this much current and how much.

How about photos of your "daisy chain" to the Tortoises, Julian - these are the only joints not inspected.

DaveB

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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sun Mar 12, 2023 12:46 pm

Hi Alan, Dave and Martin

Could I check the absolute basic before I go further - have I wired this right?

Please say if anything below is wrong.

Just to show you another test, I've eliminated any possibility that it is something to do with the lever frame (momentary shorting or whatever) or switches on it, by rigging up two unused microswitches to the two unused point motors (one is the catch point motor which is installed under the baseboard, its 8 wires come to an 8way choc block, so far unconnected to anything beyond).

So there is nothing here that was on the previous tests except the diode arrangement and wires coming from it.

Exactly the same thing happens - while only one motor is connected it runs properly, connect up the yellow and grey wires and both run slow in the same pattern as I showed right at the start.



Can I say that for this test whether the turnout lies Normal or Reverse is of no relevance.

[I'll edit this with photos to illustrate the below]

So here are the wires from the diodes. Orange and grey twisted into a pair, yellow loose.

20230312_110221.jpg


Then here is the 6 way choc block, 3 from each switch.

20230312_111506.jpg


20230312_111624.jpg


The blue wires connect to each motor. The grey and yellow from diodes connect in to the left (catch point) terminals. The orange loops round ...

20230312_111632.jpg



to the new motor which has two choc block teminals. (I've wired all turnout motor leads yellow to the associated terminal block). The blue wire connects to the other terminal. Another orange wire links this orange terminal to one terminal on the catch point below the baseboard.

20230312_111732.jpg


So far only the catch point is fully wired and works properly in both directions.

Now to connect the other uninstalled new motor I simply add loops of grey and yellow wires between the appropriate 6 way choc block terminals.

20230312_111926.jpg


PS I thought Martin had established the diodes were working as they should with the test light procedure and other questions/answers at that stage.
Here is the enormous blob of solder :P

20230312_123515.jpg
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Last edited by Julian Roberts on Sun Mar 12, 2023 1:03 pm, edited 1 time in total.

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Re: Tortoise 16v AC circuit problems

Postby grovenor-2685 » Sun Mar 12, 2023 12:54 pm

Well now, the measurements you gave to my question clearly showed one diode not working, but I have trouble believing those measurements since you also say one point works in both directions.
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Re: Tortoise 16v AC circuit problems

Postby davebradwell » Sun Mar 12, 2023 1:26 pm

Rushed back from my day out yesterday to see what strange fault had been found but still no solution. Will this become the latest media storm?

I'm still sticking to my dud joint theory. It seems unlikely to be the transformer volts sagging - the biggest load is 4 stalled motors and it bursts into life with only 3 stalled or detects the change between 1 and 2. Mind, this also weakens my joint theory!

Try this - with all motors normal you're putting all load on one side of the ac, possibly making it non-symmetrical or distorting it. This puts more volts on the other, unused, side hence greater initial speed. Do you have another transformer to substitute, Julian? We haven't seen what you're using.

Can you measure the resistance of a Tortoise with nothing connected? You can use that backwards scale at last.

Keith, I think the dud diode turned out to be the meter connected the wrong way round.

DaveB

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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sun Mar 12, 2023 1:27 pm

grovenor-2685 wrote:Well now, the measurements you gave to my question clearly showed one diode not working, but I have trouble believing those measurements since you also say one point works in both directions.


As Martin guessed, I measured one incorrectly. Where I said no needle movement I should have said 10 (reading the top row of numbers, incorrectly as Martin also guessed)

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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sun Mar 12, 2023 1:38 pm

davebradwell wrote:Rushed back from my day out yesterday to see what strange fault had been found but still no solution. Will this become the latest media storm?

I'm still sticking to my dud joint theory. It seems unlikely to be the transformer volts sagging - the biggest load is 4 stalled motors and it bursts into life with only 3 stalled or detects the change between 1 and 2. Mind, this also weakens my joint theory!

Try this - with all motors normal you're putting all load on one side of the ac, possibly making it non-symmetrical or distorting it. This puts more volts on the other, unused, side hence greater initial speed. Do you have another transformer to substitute, Julian? We haven't seen what you're using.

Can you measure the resistance of a Tortoise with nothing connected? You can use that backwards scale at last.

Keith, I think the dud diode turned out to be the meter connected the wrong way round.

DaveB


Hi Dave

:D

Ahh...I now see re the wrongly answered Keith question - I didn't realise the probes had to be a certain way round for that answer.

Going to be busy next few hours; meanwhile can you describe or remind me how I measure the Tortoise resistance?

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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sun Mar 12, 2023 1:47 pm

Forgot to say Dave, the transformer is a new Gaugemaster, I did try another (old) one, no difference

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Re: Tortoise 16v AC circuit problems

Postby Tony Wilkins » Sun Mar 12, 2023 1:48 pm

I have been wondering when resistance measurement would come up. That meter is very old and I suspect the internal battery will be flat by now if it has never been changed, so I would check the state of that first. Switch the meter to the lowest ohms range and connect the two probes together, the needle should go all the way to the right reading zero ohms, my betting is that it won't. There should be a screw to remove the back of the case to get at the AA battery.
If the meter does read zero then connect the probes across the motor terminals of the Tortoise motor with NOTHING else connected to it and see what reading you get.
PS I have just measured one I have here and get a reading of about 700ohms.
Regards
Tony.
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Julian Roberts
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Re: Tortoise 16v AC circuit problems

Postby Julian Roberts » Sun Mar 12, 2023 3:51 pm

Hi Tony

Thanks

Found a moment to reply. New battery last week. Reading -

20230312_152939.jpg


To Tortoise- - wires not connected to anything

Two photos on different settings



20230312_154446.jpg


20230312_154340.jpg
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