iPhone touchscreens on Class 800/801

[cjmillsnun]

With both the current is return to the running rails, but the earthing arrangements are different:
On OHLE the running rails are locally earthed to prevent excessive (unsafe) voltage on the running rails
where as on 3rd rail they aren't earthed (e.g. neutral).
Overall this suggest the issue is on the AC rectification side e.g. in the 4 quadrant converter...

how can anything DC be neutral? It’s either positive or negative. The running rails being the negative return nominally at 0v.

Again local earthing doesn’t reduce voltage in the running rail for AC but references those voltages to earth (here the term neutral is correct)

this makes the running rails safe to touch in both cases

note I’m not advocating touching running rails. They may be electrically safe in themselves but there are many other dangers around.

 

[Starmill]

Because, I assume, he is not an expert on the intricacies of earthing of power systems on trains.

I think it is far more likely, from what I've heard their staff and representatives saying, that LNER do view it as a problem, even if, in technical terms, it is more accurately described as a feature.

Whether or not LNER are going to do anything about it remains to be seen.

 

[hwl]

how can anything DC be neutral? It’s either positive or negative. The running rails being the negative return nominally at 0v.

Again local earthing doesn’t reduce voltage in the running rail for AC but references those voltages to earth (here the term neutral is correct)

this makes the running rails safe to touch in both cases

note I’m not advocating touching running rails. They may be electrically safe in themselves but there are many other dangers around.

Because 3rd rail is earthed remotely at supply point rather than frequently locally like OHLE. The 3rd rail running rail voltage is very rarely nominally 0 under load especially due to much higher currents in practice which combined with different earthing requirements makes AC/DC changeover areas very difficult and complex to engineer makes

 

[Mojo]

I thought they had fixed this issue as I certainly didn’t experience it last time I went to York, but my other half is on an 800 with LNER this evening and reports his phone is totally unusable with phantom touch screen presses and so on.

Does it only apply to the bi-mode units when on electric mode or did the fault not occur/the fix omitted only on certain units?

 

[Jimini]

Still happens to me all the time on the 80x fleet out of Paddington (unless it’s on diesel for some reason). Tres annoying.

 

[TT-ONR-NRN]

I thought they had fixed this issue as I certainly didn’t experience it last time I went to York, but my other half is on an 800 with LNER this evening and reports his phone is totally unusable with phantom touch screen presses and so on.

Does it only apply to the bi-mode units when on electric mode or did the fault not occur/the fix omitted only on certain units?

My iPhone was similarly unusable on the GWR service from Cardiff this afternoon

 

[Mag_seven]

I noticed it again this week which makes me think it had perhaps been sorted for a while?

 

[fgwrich]

I thought they had fixed this issue as I certainly didn’t experience it last time I went to York, but my other half is on an 800 with LNER this evening and reports his phone is totally unusable with phantom touch screen presses and so on.

Does it only apply to the bi-mode units when on electric mode or did the fault not occur/the fix omitted only on certain units?

I've been using a fair bit of LNERs and GWRs IETs of late, and strangely I've now only been experiencing this problem on GWRs fleet. Nothing on LNERs - even when sat underneath the Pantograph.

Oddly I did have a few problems recently on ScotRails 385s though.

 

[DanNCL]

Could a software update perhaps have caused the problem to flare up again?

 

[martin2345uk]

Haha I didn’t realise this was a thing, I thought my phone just hated GWR!

 

[D365]

Could a software update perhaps have caused the problem to flare up again?

No. The power delivery circuits have little to do with software.

The simplest explanation is that it's a consequence of the 25kV -> 750V -> 240V voltage conversion but caused specifically by the electrical architecture of the Hitachi trains.

 

[northernbelle]

No. The power delivery circuits have little to do with software.

The simplest explanation is that it's a consequence of the 25kV -> 750V -> 240V voltage conversion but caused specifically by the electrical architecture of the Hitachi trains.

I suspect it's to do with the additional equipment that's being fitted which suppresses the electrical interference that's been experienced. You can tell a set that's been fitted by the loud electrical/screech noise under the end of several intermediate cars.

Not all GWR sets have been fitted yet - I believe the East Coast sets have been a priority because of the signalling issues the electrical interference causes on the ECML and the urgency needed to sort it.

 

[JaJaWa]

Is there any way around this for passengers? Surge protector / different charger? I’d experienced this with knockoff chargers when on China Railway Highspeed but if you use a proper one you’re not affected

 

[D365]

Is there any way around this for passengers? Surge protector / different charger?

No - fundamentally it's down to the electrical noise that is introduced into the 240V circuits whilst the train is drawing traction power. There's not much that can be done to 'clean' a noisy supply once it reaches the domestic outlet.

 

[JN114]

Anecdotally, taking my iPhone out of its case so that I’m touching the bare metal of the phone seems to “cure” the interference experienced while charging.

 

[43096]

I suspect it's to do with the additional equipment that's being fitted which suppresses the electrical interference that's been experienced. You can tell a set that's been fitted by the loud electrical/screech noise under the end of several intermediate cars.

Not all GWR sets have been fitted yet - I believe the East Coast sets have been a priority because of the signalling issues the electrical interference causes on the ECML and the urgency needed to sort it.

It’s quite simply poor design: they’ve been like this since they were built.

 

[mrmartin]

Is there any way around this for passengers? Surge protector / different charger? I’d experienced this with knockoff chargers when on China Railway Highspeed but if you use a proper one you’re not affected

What I do is charge my laptop from the AC on the train then my phone off the laptop. This does seem to sort it completely. But obviously requires a laptop with you which might not be too practical.

Another way would be to just use a power bank to charge your phone, once it's finished charge the power bank off the trai.

 

[D365]

Another way would be to just use a power bank to charge your phone, once it's finished charge the power bank off the trai.

In order to ensure a 'clean' DC supply, some high-end record players do exactly this.

 

[JaJaWa]

What I do is charge my laptop from the AC on the train then my phone off the laptop. This does seem to sort it completely. But obviously requires a laptop with you which might not be too practical.

Another way would be to just use a power bank to charge your phone, once it's finished charge the power bank off the trai.

My Xiaomi power bank appears to offer “pass through” charging which I guess would also sort it (actually I use this to double the length of USB cables as you have the one from the wall to the power bank and the one from the power bank to the phone).

 

[DanNCL]

Is there any way around this for passengers? Surge protector / different charger? I’d experienced this with knockoff chargers when on China Railway Highspeed but if you use a proper one you’re not affected

I plug my phone into my laptop, which in turn is plugged into the power outlet, and that seems to fix the problem for me.

 

[boiledbeans2]

Is there any way around this for passengers? Surge protector / different charger? I’d experienced this with knockoff chargers when on China Railway Highspeed but if you use a proper one you’re not affected

Ferrite beads, at a guess. I've used it to attenuate common mode noise in my previous projects.

Ferrite bead - Wikipedia

en.wikipedia.org

Maybe this also explains why the laptop to phone technique works, because laptop chargers do have ferrite beads.

 

[northernbelle]

It’s quite simply poor design: they’ve been like this since they were built.

My point being that the noise-suppression equipment should remedy it - not all the GWR sets have fitted yet.

 

[D365]

My point being that the noise-suppression equipment should remedy it - not all the GWR sets have fitted yet.

Not sure about that - the priority is to mitigate signalling interference, as you wrote in your original post.