Upcoming Games

No games to display

Full list
Add a game

Upcoming Events

No events to display

Who makes signalling panel switches?

You are here: Home > Forum > Miscellaneous > The real thing (signalling) > Who makes signalling panel switches?

Page 1 of 1

Who makes signalling panel switches? 05/02/2022 at 10:56 #145005
lukebriner
Avatar
56 posts
I am toying with the idea of building a small NX panel for my model railway and would really like to use the standard NX panel pull-switches as opposed to momentary push-button switches so you can physically set and cancel a route. They need to be illuminated and ideally allow a label insert for the arrows.

I looked on RS and farnell but can't find anything although I appreciate that they are quite specialised.

Does anyone know who makes them or something slightly different that could be used instead?

Log in to reply
Who makes signalling panel switches? 05/02/2022 at 12:17 #145007
pedroathome
Avatar
882 posts
I'll stand to be corrected on everything I put below, bit here I go anyway.

I'm sure it's been said in the past somewhere that the buttons used on proper in panels can be in excess of £100 each.

I also understand that the push buttons used on panels are also momentary, effectively a momentary double throw switch. If it wasn't momentary, things like TORR wouldn't work.

Having played around in the past with SimSig and making a basic control panel to work with a sim, while not realistic, simple toggle switches or push buttons work just as well.

Not sure if I've answered your question or not, but hopefully I've put some perspective on what you're thinking

Log in to reply
Who makes signalling panel switches? 05/02/2022 at 13:37 #145008
bill_gensheet
Avatar
1309 posts
When discussed before, I think the conclusion was that a hobbyist needing a realistic button would be better making their own buttons (plastic rod, Biro tubes, springs, LED's) and then use either microswitches or Hall effect to detect the 'push' and 'pull' movements.
Log in to reply
Who makes signalling panel switches? 05/02/2022 at 14:24 #145009
Peter Bennet
Avatar
5355 posts
Online
Found this.

Peter

I identify as half man half biscuit - crumbs!
Log in to reply
Who makes signalling panel switches? 05/02/2022 at 14:27 #145010
jc92
Avatar
3626 posts
You be just as well using standard push and pull buttons as they have the same effect.

In the spirit of "there's a prototype for everything" here's some photos of the Paignton and Dartmouths in house built NX panel with all non standard fittings:

https://tillyweb.biz/gallery/bb/britannia.htm

The other avenue to explore would be an IFS panel. That would be easier to construct as you could have a diagram along with a separate box with the switches on, which are available from companies like RS.

If you do want took at industry supplies unipart rail might be a start but components are incredibly expensive due to the nature of their work and life expectancy etc.

"We don't stop camborne wednesdays"
Log in to reply
Who makes signalling panel switches? 05/02/2022 at 16:11 #145016
lukebriner
Avatar
56 posts
Thanks everyone for the help. I have seen a variety of panels but I thought the original switches were latching and didn't support TORR deliberately. If you pushed an entry and make a mistake, you have to "pull" it to cancel.

Anyway, it sounds like the switches are as rare as hen's teeth and more expensive so I will just look at using the normal push buttons.

How would you cancel a route? Push it again? Hold it down? Has anyone seen an example of this. Of course, I could always use the twisty entry buttons like on the restored Swindon panel so that twisting it back would cancel.

Log in to reply
Who makes signalling panel switches? 05/02/2022 at 16:52 #145020
jc92
Avatar
3626 posts
Pull to cancel normally
"We don't stop camborne wednesdays"
Log in to reply
Who makes signalling panel switches? 05/02/2022 at 17:00 #145022
Tempest Malice
Avatar
122 posts
lukebriner in post 145016 said:
Thanks everyone for the help. I have seen a variety of panels but I thought the original switches were latching and didn't support TORR deliberately. If you pushed an entry and make a mistake, you have to "pull" it to cancel.

Anyway, it sounds like the switches are as rare as hen's teeth and more expensive so I will just look at using the normal push buttons.

How would you cancel a route? Push it again? Hold it down? Has anyone seen an example of this. Of course, I could always use the twisty entry buttons like on the restored Swindon panel so that twisting it back would cancel.
The buttons effictevly have three positions.

They normally sit in the middle doing nothing, momentary press in to use them in route setting (entry or exit), momentary pull to cancel routes at that signal. (Push and pull are separate electrical contacts on the buttons)
The latching is all in the interlocking itself, not the buttons.
You can get the same level of control with any two momentary buttons, one to represent a press and one to represent a pull.

Log in to reply
The following user said thank you: lukebriner
Who makes signalling panel switches? 05/02/2022 at 17:18 #145023
clive
Avatar
2736 posts
pedroathome in post 145007 said:

I also understand that the push buttons used on panels are also momentary, effectively a momentary double throw switch. If it wasn't momentary, things like TORR wouldn't work.
That's nothing like how it works, I'm afraid.

I'm in the wrong place to dig out diagrams right now, but each button has three positions: pull, centre, and push, and is sprung to hold it at centre. There are two sets of contacts, one which are made by pushing, the other which are made by *not* pulling (i.e. they stay closed when the button is left alone or pushed, but open when it's pulled).

Pressing a signal (route entry) button causes the signal's "pressed as route start" relay to get energized. That closes the relay's contacts, which then feed current separately to the relay so that when the signaller lets go the relay stays energized (a timer eventually cuts out that current). Pressing the exit button will then close a circuit from that relay to the route relay; there is one of these for each possible route. The route relay - if all relevant conditions are correct - closes its contacts which then energize it as well, so it stays up. This process also cancels the "pressed as route start" relay for the button, freeing the circuits up to allow another route to be set.

Pulling the button breaks the current in a separate circuit. Doing this triggers the route cancelling logic, but that's conditional on approach control so it isn't a simple case of cutting the power to the route relay.

TORR works by detecting the train passing (roughly, route set properly, train has occupied two track circuits after the signal in order and then cleared the first one) and, when it's happened, triggers the same logic as pulling the button. TORR is *NOT* implemented within the signal button.

When I can get at the diagrams I need, I'll do a better description than this.

Log in to reply
Who makes signalling panel switches? 05/02/2022 at 17:43 #145024
Tempest Malice
Avatar
122 posts
clive in post 145023 said:
TORR is *NOT* implemented within the signal button.

Whilst this description is completely correct and accurate for relay interlockings as they used to be, It should probably be added, that where relay interlockings without TORR are recontrolled to computer based systems nowadays, then a thing called "TORC" (Train operated Route Cancelation) can sometimes be used instead.
Under TORC, the TDM watches the state of railway, and under the same set of conditions that TORR would have been triggered if it existed, the TDM then sends a button pull into the interlocking (even though the "button" in the control system has not actually been used). So in these cases effectively the interlocking's relays that handle the button pull are used during what effectively is TORR.
But yes in no case is the button or wiring through it itself involved, especially in any relay interlocking that does TORR itself where the two functions (buttons and TORR) are completely unrelated.

Last edited: 05/02/2022 at 17:44 by Tempest Malice
Reason: None given

Log in to reply
Who makes signalling panel switches? 05/02/2022 at 17:48 #145025
Tempest Malice
Avatar
122 posts
And back to the original topic of this discussion I've remembered that a previous time someone asked about the real buttons (on another forum so I'll just link straight to the result) I went and found a link to the manufacturers website.

Not that I imagine it is easy for individual buyers to buy them, but at least you can get some more details on what the real ones are.

Log in to reply
Who makes signalling panel switches? 05/02/2022 at 17:50 #145026
headshot119
Avatar
4869 posts
Tempest Malice in post 145025 said:
And back to the original topic of this discussion I've remembered that a previous time someone asked about the real buttons (on another forum so I'll just link straight to the result) I went and found a link to the manufacturers website.

Not that I imagine it is easy for individual buyers to buy them, but at least you can get some more details on what the real ones are.
Just a note on these, if anyone does manage to purchase any, be gentle with them, especially when pulling up to cancel!

"Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer
Log in to reply
Who makes signalling panel switches? 05/02/2022 at 23:59 #145035
clive
Avatar
2736 posts
clive in post 145023 said:

When I can get at the diagrams I need, I'll do a better description than this.
Okay. In the following "XR = YR -ZR" means relay XR is energized when relay YR is energized and relay ZR is not energized.

Let's look at the first part of setting route 5A from signal 5 to signal 9. These are typical freewired circuits from the Green Book.

The contacts on button 5 drive relays 5(F)R [5 pushed] and 5(FM)R [5 not pulled]. Contacts on all the buttons in the same signalling ring drive two relays PBCR and PBPR for the ring: PBCR is energized if no buttons are being pushed and PBPR if exactly one button is being pushed. The first key relay is 5(S)R, which is energized to indicate 5 has been pressed as an entry button and causes the lamp in button 5 to flash:

5(S)R = DJR ((-TFR PBPR -(ENT)R 5(F)R) or (5(FM)R 5(S)R)

So assuming DJR is up (energized), 5(S) will pick up when button 5 if pushed if TFR is down, PBRP is up (so only one button is being pushed at a time), and (ENT)R is down. Once it energizes, it will stay up until either DJR drops or the button is pulled. (ENT)R is energized if any #(S)R in the signalling ring is up, so 5(S)R can't pick up if another entrance button is already pushed and flashing.

Now the signaller pushes button 9. This drives the "destination" relay:

9(D)R = DJR ((TFR PBPR -(D)PR 9(F)R) or 9(D)R)

Again, this picks up if 9 is pressed on its own with no other destination already picked ((D)PR is energized if any #(D)R is) and then stays up as long as DJR does.

TFR = (ENT)R (PBCR or TFR)

TFR picks up when an entrance button is pressed *and* released, making it safe to press an exit button.

DCR = -(D)PR ((-PBPR PBCR -TFR -DJR) or DCR)
DJR = DCR with 1 second delay on release

Picking up (D)PR by pressing 9 causes DCR to drop (it's normally energized). 1 second later DJR drops, releasing 5(S)R and 9(D)R and resetting things back to the initial state, which in turn allows DCR to pick up again.

Now we come to the route setting itself. Route 5A is managed by two relays: 5ARLR, which is energized if the route is set, and 5ANLR, which is energized if it isn't set. 5ANLR is a magnetically latching relay: it has "pull up" and "release" inputs which set it up and down, but it stays in the last state it was in even if there's no input - this provides memory over a power outage.

5ARLR = 5YR(P) AA(Up)USR xxNLR yyNLR 101NZLIPR 102RZLIPR (5ARLR or (5(S)R 9(D)R)) -5ANLR
5ANLR release = 5YR(P) AA(Up)USR xxNLR yyNLR 101NZLIPR 102RZLIPR (5ARLR or (5(S)R 9(D)R)) 5ANLR
5ANLR pull up = -5YR(P) 5ALSR -5TASR -5ATSR -5ARLR

Setting 5ARLR requires no demand to cancel the route (5YR(P) drops if a route from 5 is validly cancelled), no route set to the back of the signal in the other direction, no conflicting routes set that use the same points positions (so routes xx and yy might be calling on routes from 5 or routes in the other direction), points 101 normal or free to move normal, 102 reverse or free to move reverse, and buttons 5 and 9 used to set the route. The logic first releases 5ANLR, then energizes 5ARLR, after which the state of the two buttons becomes irrelevant.

5ANLR can't be picked up again until 5ARLR has been released, there is a route release demand, and the approach locking logic (three relays here) is in the correct state.

Note it's possible for both 5ANLR and 5ARLR to be down at the same time. This represents that the route is not set but, at the same time, not definitely *not* in use, so in this state an opposing route can't be set.

There's lots more of this stuff, but hopefully it will give you a flavour.

Log in to reply
The following users said thank you: lukebriner, Hawk777
Who makes signalling panel switches? 10/02/2022 at 20:23 #145113
Edgemaster
Avatar
332 posts
Henry Williams also do spares https://hwilliams.co.uk/railways-domino-mimic/domino-spares-pushpull-kits/

I've got a stash of the ones above at work:

Post has attachments. Log in to view them.
Twitter
Last edited: 10/02/2022 at 20:35 by Edgemaster
Reason: None given

Log in to reply