I can't find it now but somebody asked on here a few months ago
whether any NSE clocks can still be found in the wild. I promised to
look out as I thought I'd seen one on the West Anglia line.
I drew a blank, failing to spot any from speeding class 745s.
Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
and noticed a steady ticking. I was sitting directly underneath a
working example. The frame is now black but there's a small sticker
attached that still bears the NSE logo.
So, whoever you were, I hope you read this and go and see it.

On 11.08.23 09:18, Ken wrote:
> I can't find it now but somebody asked on here a few months ago
> whether any NSE clocks can still be found in the wild. I promised to
> look out as I thought I'd seen one on the West Anglia line.
> I drew a blank, failing to spot any from speeding class 745s.
> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
> and noticed a steady ticking. I was sitting directly underneath a
> working example. The frame is now black but there's a small sticker
> attached that still bears the NSE logo.
> So, whoever you were, I hope you read this and go and see it.

Thanks, it was me who asked. Since I asked the question, I happened to
pass through Charing Cross station in London, and noticed that they have
lots of them, still with NSE brandign, on the platforms there, so there
definitely still are a number out there ticking away in the wild.

Robin

Bob <bob@domain.com> wrote:
> On 11.08.23 09:18, Ken wrote:
>> I can't find it now but somebody asked on here a few months ago
>> whether any NSE clocks can still be found in the wild. I promised to
>> look out as I thought I'd seen one on the West Anglia line.
>> I drew a blank, failing to spot any from speeding class 745s.
>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>> and noticed a steady ticking. I was sitting directly underneath a
>> working example. The frame is now black but there's a small sticker
>> attached that still bears the NSE logo.
>> So, whoever you were, I hope you read this and go and see it.
>
> Thanks, it was me who asked. Since I asked the question, I happened to
> pass through Charing Cross station in London, and noticed that they have
> lots of them, still with NSE brandign, on the platforms there, so there
> definitely still are a number out there ticking away in the wild.
>
>

I think you can tell from their behaviour at times when multiple digits
need to change, whether or not they've had new control circuitry installed.

The original wiring has 14 wires connecting all the digits in parallel; an
'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
return circuit from each digit it controlled independently. Thus to change
a particular digit, you energise the appropriate seven of the 14 input
wires, and briefly connect the return circuit for the appropriate digit.
You can see that if multiple of the 'return' circuits are connected
simultaneously, the appropriate digits will change at the same time
(provided sufficient current is available to drive multiples of segments at
once), but they can only change *to display the same figure*. Thus to
change multiple digits, it's done in turn - the change to 10am, 8pm and
midnight is particularly impressive with all six digits flipping in
sequence.

I've noticed at least one (either IRL or on a video, I don't recall which)
where multiple digits changed at once; an action clearly not possible with
the original wiring.

A friend once purchased one of these clocks on eBay - they're much bigger
on the floor than they look up in the air!! And heavy too. The previous
owner had wired in a switch which bypassed the requirement for a central
time-signal, and started counting up in seconds from all-zero when you
switched it on. One evening returning from the pub we decided to switch it
on for a while (it was loud, so not left on all the time!). After a few
minutes, segments started randomly changing at the same time, different
segments on different digits changing simultaneously. Having studied the
wiring together, we knew that what was happening was not actually
physically/electronically possible!! After *very* quickly switching it off,
we decided it must be haunted :D. That was around 20 years ago and my
friend is still in the occasional process of building new control circuitry
for it…

Anna Noyd-Dryver

On 11.08.23 16:35, Anna Noyd-Dryver wrote:
> Bob <bob@domain.com> wrote:
>> On 11.08.23 09:18, Ken wrote:
>>> I can't find it now but somebody asked on here a few months ago
>>> whether any NSE clocks can still be found in the wild. I promised to
>>> look out as I thought I'd seen one on the West Anglia line.
>>> I drew a blank, failing to spot any from speeding class 745s.
>>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>>> and noticed a steady ticking. I was sitting directly underneath a
>>> working example. The frame is now black but there's a small sticker
>>> attached that still bears the NSE logo.
>>> So, whoever you were, I hope you read this and go and see it.
>>
>> Thanks, it was me who asked. Since I asked the question, I happened to
>> pass through Charing Cross station in London, and noticed that they have
>> lots of them, still with NSE brandign, on the platforms there, so there
>> definitely still are a number out there ticking away in the wild.
>>
>>
>
> I think you can tell from their behaviour at times when multiple digits
> need to change, whether or not they've had new control circuitry installed.
>
> The original wiring has 14 wires connecting all the digits in parallel; an
> 'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
> return circuit from each digit it controlled independently. Thus to change
> a particular digit, you energise the appropriate seven of the 14 input
> wires, and briefly connect the return circuit for the appropriate digit.
> You can see that if multiple of the 'return' circuits are connected
> simultaneously, the appropriate digits will change at the same time
> (provided sufficient current is available to drive multiples of segments at
> once), but they can only change *to display the same figure*. Thus to
> change multiple digits, it's done in turn - the change to 10am, 8pm and
> midnight is particularly impressive with all six digits flipping in
> sequence.
>
> I've noticed at least one (either IRL or on a video, I don't recall which)
> where multiple digits changed at once; an action clearly not possible with
> the original wiring.

It's interesting you say this. For a short period in my younger years I
happened to routinely catch a train at shortly after 20.00 at an NSE
station (it was so in those days), and for want of anything more
interesting to do, I paid attention to the clock changing. I am quite
certain the clock at that station changed all the digits simultaneously,
though there definitely were ones at the time that changed sequentially
as you describe.

It could be that the clocks were, electrically, not all the same, and
that perhaps both types existed in the wild.

Robin

Bob <bob@domain.com> wrote:
> On 11.08.23 16:35, Anna Noyd-Dryver wrote:
>> Bob <bob@domain.com> wrote:
>>> On 11.08.23 09:18, Ken wrote:
>>>> I can't find it now but somebody asked on here a few months ago
>>>> whether any NSE clocks can still be found in the wild. I promised to
>>>> look out as I thought I'd seen one on the West Anglia line.
>>>> I drew a blank, failing to spot any from speeding class 745s.
>>>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>>>> and noticed a steady ticking. I was sitting directly underneath a
>>>> working example. The frame is now black but there's a small sticker
>>>> attached that still bears the NSE logo.
>>>> So, whoever you were, I hope you read this and go and see it.
>>>
>>> Thanks, it was me who asked. Since I asked the question, I happened to
>>> pass through Charing Cross station in London, and noticed that they have
>>> lots of them, still with NSE brandign, on the platforms there, so there
>>> definitely still are a number out there ticking away in the wild.
>>>
>>>
>>
>> I think you can tell from their behaviour at times when multiple digits
>> need to change, whether or not they've had new control circuitry installed.
>>
>> The original wiring has 14 wires connecting all the digits in parallel; an
>> 'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
>> return circuit from each digit it controlled independently. Thus to change
>> a particular digit, you energise the appropriate seven of the 14 input
>> wires, and briefly connect the return circuit for the appropriate digit.
>> You can see that if multiple of the 'return' circuits are connected
>> simultaneously, the appropriate digits will change at the same time
>> (provided sufficient current is available to drive multiples of segments at
>> once), but they can only change *to display the same figure*. Thus to
>> change multiple digits, it's done in turn - the change to 10am, 8pm and
>> midnight is particularly impressive with all six digits flipping in
>> sequence.
>>
>> I've noticed at least one (either IRL or on a video, I don't recall which)
>> where multiple digits changed at once; an action clearly not possible with
>> the original wiring.
>
> It's interesting you say this. For a short period in my younger years I
> happened to routinely catch a train at shortly after 20.00 at an NSE
> station (it was so in those days), and for want of anything more
> interesting to do, I paid attention to the clock changing. I am quite
> certain the clock at that station changed all the digits simultaneously,
> though there definitely were ones at the time that changed sequentially
> as you describe.
>
> It could be that the clocks were, electrically, not all the same, and
> that perhaps both types existed in the wild.
>
>

Very interesting, I suspect you're right. It's great to get some first-hand
observations about this!

Anna Noyd-Dryver

On Fri, 11 Aug 2023 18:30:56 -0000 (UTC), Anna Noyd-Dryver
<anna@noyd-dryver.com> wrote:

>Bob <bob@domain.com> wrote:
>> On 11.08.23 16:35, Anna Noyd-Dryver wrote:
>>> Bob <bob@domain.com> wrote:
>>>> On 11.08.23 09:18, Ken wrote:
>>>>> I can't find it now but somebody asked on here a few months ago
>>>>> whether any NSE clocks can still be found in the wild. I promised to
>>>>> look out as I thought I'd seen one on the West Anglia line.
>>>>> I drew a blank, failing to spot any from speeding class 745s.
>>>>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>>>>> and noticed a steady ticking. I was sitting directly underneath a
>>>>> working example. The frame is now black but there's a small sticker
>>>>> attached that still bears the NSE logo.
>>>>> So, whoever you were, I hope you read this and go and see it.
>>>>
>>>> Thanks, it was me who asked. Since I asked the question, I happened to
>>>> pass through Charing Cross station in London, and noticed that they have
>>>> lots of them, still with NSE brandign, on the platforms there, so there
>>>> definitely still are a number out there ticking away in the wild.
>>>>
>>>>
>>>
>>> I think you can tell from their behaviour at times when multiple digits
>>> need to change, whether or not they've had new control circuitry installed.
>>>
>>> The original wiring has 14 wires connecting all the digits in parallel; an
>>> 'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
>>> return circuit from each digit it controlled independently. Thus to change
>>> a particular digit, you energise the appropriate seven of the 14 input
>>> wires, and briefly connect the return circuit for the appropriate digit.
>>> You can see that if multiple of the 'return' circuits are connected
>>> simultaneously, the appropriate digits will change at the same time
>>> (provided sufficient current is available to drive multiples of segments at
>>> once), but they can only change *to display the same figure*. Thus to
>>> change multiple digits, it's done in turn - the change to 10am, 8pm and
>>> midnight is particularly impressive with all six digits flipping in
>>> sequence.
>>>
>>> I've noticed at least one (either IRL or on a video, I don't recall which)
>>> where multiple digits changed at once; an action clearly not possible with
>>> the original wiring.
>>
>> It's interesting you say this. For a short period in my younger years I
>> happened to routinely catch a train at shortly after 20.00 at an NSE
>> station (it was so in those days), and for want of anything more
>> interesting to do, I paid attention to the clock changing. I am quite
>> certain the clock at that station changed all the digits simultaneously,
>> though there definitely were ones at the time that changed sequentially
>> as you describe.
>>
>> It could be that the clocks were, electrically, not all the same, and
>> that perhaps both types existed in the wild.
>>
>>
>
>Very interesting, I suspect you're right. It's great to get some first-hand
>observations about this!
>
ISTR all digits changing together (DC line). Doing so presumably
involves a higher peak load and more chance of blowing a fuse or
overloading or EMPing the control circuitry. That could cause
different makers to produce different control circuits or the same
maker to change the control circuit if that problem actually occurred.

Charles Ellson <charlesellson@btinternet.com> wrote:
> On Fri, 11 Aug 2023 18:30:56 -0000 (UTC), Anna Noyd-Dryver
> <anna@noyd-dryver.com> wrote:
>
>> Bob <bob@domain.com> wrote:
>>> On 11.08.23 16:35, Anna Noyd-Dryver wrote:
>>>> Bob <bob@domain.com> wrote:
>>>>> On 11.08.23 09:18, Ken wrote:
>>>>>> I can't find it now but somebody asked on here a few months ago
>>>>>> whether any NSE clocks can still be found in the wild. I promised to
>>>>>> look out as I thought I'd seen one on the West Anglia line.
>>>>>> I drew a blank, failing to spot any from speeding class 745s.
>>>>>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>>>>>> and noticed a steady ticking. I was sitting directly underneath a
>>>>>> working example. The frame is now black but there's a small sticker
>>>>>> attached that still bears the NSE logo.
>>>>>> So, whoever you were, I hope you read this and go and see it.
>>>>>
>>>>> Thanks, it was me who asked. Since I asked the question, I happened to
>>>>> pass through Charing Cross station in London, and noticed that they have
>>>>> lots of them, still with NSE brandign, on the platforms there, so there
>>>>> definitely still are a number out there ticking away in the wild.
>>>>>
>>>>>
>>>>
>>>> I think you can tell from their behaviour at times when multiple digits
>>>> need to change, whether or not they've had new control circuitry installed.
>>>>
>>>> The original wiring has 14 wires connecting all the digits in parallel; an
>>>> 'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
>>>> return circuit from each digit it controlled independently. Thus to change
>>>> a particular digit, you energise the appropriate seven of the 14 input
>>>> wires, and briefly connect the return circuit for the appropriate digit.
>>>> You can see that if multiple of the 'return' circuits are connected
>>>> simultaneously, the appropriate digits will change at the same time
>>>> (provided sufficient current is available to drive multiples of segments at
>>>> once), but they can only change *to display the same figure*. Thus to
>>>> change multiple digits, it's done in turn - the change to 10am, 8pm and
>>>> midnight is particularly impressive with all six digits flipping in
>>>> sequence.
>>>>
>>>> I've noticed at least one (either IRL or on a video, I don't recall which)
>>>> where multiple digits changed at once; an action clearly not possible with
>>>> the original wiring.
>>>
>>> It's interesting you say this. For a short period in my younger years I
>>> happened to routinely catch a train at shortly after 20.00 at an NSE
>>> station (it was so in those days), and for want of anything more
>>> interesting to do, I paid attention to the clock changing. I am quite
>>> certain the clock at that station changed all the digits simultaneously,
>>> though there definitely were ones at the time that changed sequentially
>>> as you describe.
>>>
>>> It could be that the clocks were, electrically, not all the same, and
>>> that perhaps both types existed in the wild.
>>>
>>>
>>
>> Very interesting, I suspect you're right. It's great to get some first-hand
>> observations about this!
>>
> ISTR all digits changing together (DC line). Doing so presumably
> involves a higher peak load and more chance of blowing a fuse or
> overloading or EMPing the control circuitry. That could cause
> different makers to produce different control circuits or the same
> maker to change the control circuit if that problem actually occurred.

My memory of Thameslink land was that they didn’t all change together- you
could tell when a minute had passed without looking at the display simply
by distinctive sounds it made when the minute advanced… particularly on the
10-minute intervals.

Add to that the wonderful mechanical sounds that the quick fare ticket
machines would make when accepting coins and printing tickets, it made for
an atmospheric experience!

On Fri, 11 Aug 2023 20:10:55 -0000 (UTC), Lew1 <email@nowhere.com>
wrote:

>Charles Ellson <charlesellson@btinternet.com> wrote:
>> On Fri, 11 Aug 2023 18:30:56 -0000 (UTC), Anna Noyd-Dryver
>> <anna@noyd-dryver.com> wrote:
>>
>>> Bob <bob@domain.com> wrote:
>>>> On 11.08.23 16:35, Anna Noyd-Dryver wrote:
>>>>> Bob <bob@domain.com> wrote:
>>>>>> On 11.08.23 09:18, Ken wrote:
>>>>>>> I can't find it now but somebody asked on here a few months ago
>>>>>>> whether any NSE clocks can still be found in the wild. I promised to
>>>>>>> look out as I thought I'd seen one on the West Anglia line.
>>>>>>> I drew a blank, failing to spot any from speeding class 745s.
>>>>>>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>>>>>>> and noticed a steady ticking. I was sitting directly underneath a
>>>>>>> working example. The frame is now black but there's a small sticker
>>>>>>> attached that still bears the NSE logo.
>>>>>>> So, whoever you were, I hope you read this and go and see it.
>>>>>>
>>>>>> Thanks, it was me who asked. Since I asked the question, I happened to
>>>>>> pass through Charing Cross station in London, and noticed that they have
>>>>>> lots of them, still with NSE brandign, on the platforms there, so there
>>>>>> definitely still are a number out there ticking away in the wild.
>>>>>>
>>>>>>
>>>>>
>>>>> I think you can tell from their behaviour at times when multiple digits
>>>>> need to change, whether or not they've had new control circuitry installed.
>>>>>
>>>>> The original wiring has 14 wires connecting all the digits in parallel; an
>>>>> 'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
>>>>> return circuit from each digit it controlled independently. Thus to change
>>>>> a particular digit, you energise the appropriate seven of the 14 input
>>>>> wires, and briefly connect the return circuit for the appropriate digit.
>>>>> You can see that if multiple of the 'return' circuits are connected
>>>>> simultaneously, the appropriate digits will change at the same time
>>>>> (provided sufficient current is available to drive multiples of segments at
>>>>> once), but they can only change *to display the same figure*. Thus to
>>>>> change multiple digits, it's done in turn - the change to 10am, 8pm and
>>>>> midnight is particularly impressive with all six digits flipping in
>>>>> sequence.
>>>>>
>>>>> I've noticed at least one (either IRL or on a video, I don't recall which)
>>>>> where multiple digits changed at once; an action clearly not possible with
>>>>> the original wiring.
>>>>
>>>> It's interesting you say this. For a short period in my younger years I
>>>> happened to routinely catch a train at shortly after 20.00 at an NSE
>>>> station (it was so in those days), and for want of anything more
>>>> interesting to do, I paid attention to the clock changing. I am quite
>>>> certain the clock at that station changed all the digits simultaneously,
>>>> though there definitely were ones at the time that changed sequentially
>>>> as you describe.
>>>>
>>>> It could be that the clocks were, electrically, not all the same, and
>>>> that perhaps both types existed in the wild.
>>>>
>>>>
>>>
>>> Very interesting, I suspect you're right. It's great to get some first-hand
>>> observations about this!
>>>
>> ISTR all digits changing together (DC line). Doing so presumably
>> involves a higher peak load and more chance of blowing a fuse or
>> overloading or EMPing the control circuitry. That could cause
>> different makers to produce different control circuits or the same
>> maker to change the control circuit if that problem actually occurred.
>
>My memory of Thameslink land was that they didn’t all change together- you
>could tell when a minute had passed without looking at the display simply
>by distinctive sounds it made when the minute advanced… particularly on the
>10-minute intervals.
>
>Add to that the wonderful mechanical sounds that the quick fare ticket
>machines would make when accepting coins and printing tickets, it made for
>an atmospheric experience!
>
What was also noticeable on the DC line was the distinct thump! when
the clock changed to the next hour, somewhat more than those at the
lesser intervals.

Lew1 <email@nowhere.com> wrote:
> My memory of Thameslink land was that they didn’t all change together- you
> could tell when a minute had passed without looking at the display simply
> by distinctive sounds it made when the minute advanced… particularly on the
> 10-minute intervals.

That's my memory of mid-90s SWT land too - the sound on minute/tens/hour
changes wasn't just louder, but longer too.

This kind of digit multiplexing is common in multi-digit 7 segment LED
displays, where you save wiring by having 7 segment wires and digit select
wiring rather than a wire to every segment of every digit. However there
the digits don't remember their previous state, so you have to select each
digit at Hz or kHz so it appears they're all lit.

It sounds like a fun challenge to adapt that to a mechanism where the state
is remembered mechanically and you send the differences instead.

Theo

On 11.08.23 20:30, Anna Noyd-Dryver wrote:
> Bob <bob@domain.com> wrote:
>> On 11.08.23 16:35, Anna Noyd-Dryver wrote:
>>> Bob <bob@domain.com> wrote:
>>>> On 11.08.23 09:18, Ken wrote:
>>>>> I can't find it now but somebody asked on here a few months ago
>>>>> whether any NSE clocks can still be found in the wild. I promised to
>>>>> look out as I thought I'd seen one on the West Anglia line.
>>>>> I drew a blank, failing to spot any from speeding class 745s.
>>>>> Yesterday I was sitting at my nearest station, Stansted Mountfitchet,
>>>>> and noticed a steady ticking. I was sitting directly underneath a
>>>>> working example. The frame is now black but there's a small sticker
>>>>> attached that still bears the NSE logo.
>>>>> So, whoever you were, I hope you read this and go and see it.
>>>>
>>>> Thanks, it was me who asked. Since I asked the question, I happened to
>>>> pass through Charing Cross station in London, and noticed that they have
>>>> lots of them, still with NSE brandign, on the platforms there, so there
>>>> definitely still are a number out there ticking away in the wild.
>>>>
>>>>
>>>
>>> I think you can tell from their behaviour at times when multiple digits
>>> need to change, whether or not they've had new control circuitry installed.
>>>
>>> The original wiring has 14 wires connecting all the digits in parallel; an
>>> 'on' and 'off' for each segment. Each digit is 'earthed' separately, ie the
>>> return circuit from each digit it controlled independently. Thus to change
>>> a particular digit, you energise the appropriate seven of the 14 input
>>> wires, and briefly connect the return circuit for the appropriate digit.
>>> You can see that if multiple of the 'return' circuits are connected
>>> simultaneously, the appropriate digits will change at the same time
>>> (provided sufficient current is available to drive multiples of segments at
>>> once), but they can only change *to display the same figure*. Thus to
>>> change multiple digits, it's done in turn - the change to 10am, 8pm and
>>> midnight is particularly impressive with all six digits flipping in
>>> sequence.
>>>
>>> I've noticed at least one (either IRL or on a video, I don't recall which)
>>> where multiple digits changed at once; an action clearly not possible with
>>> the original wiring.
>>
>> It's interesting you say this. For a short period in my younger years I
>> happened to routinely catch a train at shortly after 20.00 at an NSE
>> station (it was so in those days), and for want of anything more
>> interesting to do, I paid attention to the clock changing. I am quite
>> certain the clock at that station changed all the digits simultaneously,
>> though there definitely were ones at the time that changed sequentially
>> as you describe.
>>
>> It could be that the clocks were, electrically, not all the same, and
>> that perhaps both types existed in the wild.
>>
>>
>
> Very interesting, I suspect you're right. It's great to get some first-hand
> observations about this!

A little bit of youtube trawling has turned up this video [1]. At 6.52
you can see an NSE clock at Liverpool St tick over from 08:46:29 to
08:46:30 with the digits switching simultaneously rather than
sequentially. The caption on the video suggests it's 1994, so not quite
NSE but close enough to beleive the clock is unmodified from NSE days.

[1] https://youtu.be/AyZlooep1PY

Robin

Theo <theom+news@chiark.greenend.org.uk> wrote:
> Lew1 <email@nowhere.com> wrote:
>> My memory of Thameslink land was that they didn’t all change together- you
>> could tell when a minute had passed without looking at the display simply
>> by distinctive sounds it made when the minute advanced… particularly on the
>> 10-minute intervals.
>
> That's my memory of mid-90s SWT land too - the sound on minute/tens/hour
> changes wasn't just louder, but longer too.
>
> This kind of digit multiplexing is common in multi-digit 7 segment LED
> displays, where you save wiring by having 7 segment wires and digit select
> wiring rather than a wire to every segment of every digit. However there
> the digits don't remember their previous state, so you have to select each
> digit at Hz or kHz so it appears they're all lit.
>
> It sounds like a fun challenge to adapt that to a mechanism where the state
> is remembered mechanically and you send the differences instead.
>
>

You don't have to work out the differences, because each segment has an
‘on’ input and an ‘off’ input, and if the input energised is the same as
the segment is already displaying, then nothing bad happens (I guess a
little electricity is wasted in briefly powering the solenoid for no
reason).

Anna Noyd-Dryver