Maintenance

[Penri]

Hello again

The rest of the traces

Right to left (TEK0004)

TEK0004.JPG (247.68 KiB) Viewed 290 times

No motion (TEK0005)

TEK0005.JPG (170.04 KiB) Viewed 290 times

Right to left (TEK0006)

TEK0006.JPG (193.48 KiB) Viewed 290 times

Left to right (TEK0007)

TEK0007.JPG (195.44 KiB) Viewed 290 times

Penri

[TerryJC]

Penri,

I'm not sure what is going on in these images or in the videos that you put on your Google Drive. On the face of it (and notwithstanding the weird shape of the waveforms) the functionality seems OK apart from the failure of the train to reach it's place on the track.

Part of my problem is that we've never monitored these waveforms before, so I have nothing to compare them with. The train itself in the video IMG_7033.mov seems a bit slow, but not enormously so. There definitely seems to be a very truncated run time and I think that the system has developed a fault on the Sensor B detection circuits. Unless I've misunderstood that video, the train is actually starting from the middle of the track instead of the station at the Store End. In that case, Sensor B (which is located at the entrance to the tunnel) should never have been triggered and the train should have run for:

• 2 seconds to accelerate.
• 7 seconds waiting for the non-existent sensor.
• 2 seconds to decelerate.

The fault may lie in the sensor, in the wiring to the system, in the buffer on the Veroboard or in the wiring to the GPIO Pin 6 (Board Pin 31). It might be worth trying to reseat the wiring if you cannot see a short anywhere (the Pin is pulled up in the Pi and the triggered signal is a 0 V at the sensor).

BTW. What is the red trace in your video IMG_7031.mov?

[Penri]

Terry

I think I explained the red trace somewhere, possibly in the Google Drive invitation, anyway its Channel 2 minus Channel 1, a maths calculation done within the scope, in effect it what the trains motor should be seeing.
The scope probes were both referenced to 0V on the Control Assembly.


Penri

[TerryJC]

I think I explained the red trace somewhere

You did and I missed it.

[Penri]

Hello
Had some time this morning and WMT was fairly quiet.
The underground train was at the right hand end of the track and only moving in and out of the tunnel a short way.
I switched off mains supplies to all bar the underground with no change to its behaviour.
I then switched off the mains supply to the layout and removed the plugs from their sockets, then ran an extension lead from the mains socket outside the railway store into which I plugged the three mains plugs associated with the underground. Lo and behold the underground train ran the full length of travel, with appropriate stops.
I then reconnected the layout, with underground still on the extension lead, the underground continued to operate correctly under ‘button’ control.
Finally I plugged the underground mains supplies back into the socket strip, removing the extension lead and damn me it still continued to work normally.
It’s now been working as it should for a couple of hours.
Mystified, I certainly am!

[TerryJC]

It's magic

I was going to ask you if any progress had been made on this because it has been some time since it was last discussed it.

I've had 'one or two' minor and major domestic failures recently, not least of which was the big bang from our induction hob Needless to say the unit is no longer supported and there aren't many out there of the same shape and size to fit the hole in the worktop. The replacement arrived today and now has to be installed...

[Penri]

As you will have worked out from the methodology I was trying to isolate the underground electrically. I would have preferred to do it on the DC side but without a wiring / circuit diagram not a task I'd want to undertake unless it was to rationalise the whole lot.
Anyway I was happy to be in the right track up until I plugged the underground back into its socket strip, I fully expected it to fall over and when it didn't ... .
The one thing I did establish, which may have been obvious to others, is that the underground can be electrically isolated and run, but needs a supply from elsewhere to interface with the hand wave activation circuit, do you know how that's configured by any chance?

Not particularly good news on the hob front, we've been contemplating replacing our gas one with an electric version and have been agonising with the thought of modifying a granite worktop.

[TerryJC]

The one thing I did establish, which may have been obvious to others, is that the underground can be electrically isolated and run, but needs a supply from elsewhere to interface with the hand wave activation circuit, do you know how that's configured by any chance?

I'm afraid not.

Not particularly good news on the hob front, we've been contemplating replacing our gas one with an electric version and have been agonising with the thought of modifying a granite worktop.

It's not all bad. The old hob is 10+ years old. The biggest problem is the cutout; ours is 90 cm wide and only 33 cm front to back. These were very much in fashion 10-12 years ago and matched the width of the double oven. Nowadays the more convention 60 cm wide and correspondingly deeper format is much more common.

[Penri]

Today's update: the underground continues to run perfectly.

I'm only reporting this because the whole system would have been turned off overnight and re-started this morning. That process would only have involved throwing the two switches on the wall socket so minimal interaction with the layout.

It will be interesting to see if the "fix" survives the Railway Team going about their regular cleaning and maintenance activity tomorrow. It's not that they are likely to do anything wrong, but they just might touch, move or interact with the layout in a way that could re-trigger the abnormal running pattern, I'll ask them to look out for it.

[TerryJC]

Let's hope that the system survives until the end of the month when we can strip it out and fully check both halves.