Restoring Miniature Webb and Thompson ETS Machines

[madscientist]

Ive not put this topic in Signalling - Overseas, as its general call for help.

I have undertaken to restore to working order , two W&T miniature ETS machines as used to be found all over Ireland. I have three such machines and hope to get two fully restored and working as a pair. None of them are pairs to begin with, so that may cause some issues


what I am looking for is help on wiring , access to knowledge etc or anyone that knows these units in whatever form.

These units have a plain galvanometer , and an integral bell push , which suggests they were powered by battery , as hand generator units had the bell push on the generator in my experience

I presume these use standard -50V DC telephone power, anyone any idea of the type of current they might draw , when the relays operated. ?, I have to rig up a suitable DC supply and the nearest common voltage is 48 V which should be sufficient


thanks in advance

Dave

Moderator Note: Topic moved to S&T Department as its more appropriate there.

[MRFS]

I have *ooooodles* of circuits.

Can you tell me first off:

A) Are all the instruments terminal (i.e. not intermediates): do they all have one galvo?

B) What sort of lock do they have? Is there a Z-shaped piece that swings across and bounces up with the lock, or are there 4 coils in two pairs?

Photos of the internals may be easier - also, can you tell me what the MXXXX or SXXXX number is on the front, please?

[madscientist]

Oops , lots of questions.

There are definitely terminal equipment

Next Saturday is the next opportunity to examine them. I'll take a picture of the insides/outsides

Thanks very much

Dave

[Fast Line Floyd]

The two that I restored for the Inspector would happily release on 12v and the current was less than half an amp.

[JRB]

Yes, 50V is telephone voltage. Signalling equipment (block, bells, token &c.) would not normally go above 12V. Line voltage would often be more to compensate for line wire resistance, but only to give 12V or less at the receiving end.

[madscientist]

Ok that's good news. I need next to find out exactly what version I have

[madscientist]

I have taken some pictures https://www.dropbox.com/sh/xuma40yudavn ... CqoDa?dl=0, There are two machine , one basically complete internally ( it seems ) but missing its advance starter key lock and the other was repainted but was in a fire and the electrics are missing , but it still has its starter release key

dave

[Colin Rutledge]

The photos show S type miniature instruments.
In Victoria Australia we did not have S type instruments but had lots of standard battery instruments and M type miniature battery types. Later on many were converted to magneto type working using the same coil arrangement as in the S type instruments.
All instruments were set up using current as the determining factor. For battery instruments we added more 1.5V No6 dry cells until we achieved just over the specified values. All our instruments with S type coils were known as magneto types as they were operated by a hand magneto generator that had sufficient current and voltage to deal with about 50 miles of 200lb copper wire which has a resistance of around 3.5 ohms per copper single wire mile.
Battery Instruments, local coils 125mA usually 5 cells
Battery Instruments, line coils 115 - 130mA about 15 cells for the first mile. Then 2 cell per mile up to 30 cells then add 10% less for each successive 30 cells.
Magneto Instruments, 70 - 80mA.

Resistance of the various components,
Battery Instrument, local coils 60 ohms. Line coils 90 ohms. Galvo 10 ohms. Single stroke bell 30 - 45 ohms
Magneto Instrument, lock coil 120 ohms. Galvo 10 ohms. Single stroke bell 90 ohms.

[JRB]

Indeed, current rather than voltage has always been the factor normally considered in this context: bells, block, staff, tablet & token.

[Pete2320]

Some useful information there Colin. I'll just add that the indicator on the instrument that has one is an L type, there were others the most common type just has a centre pivoted vertical newbie and no staff in/out indicator.
Do you know what configuration these instruments are? The majority in Ireland seem to have been A or B but there must have been others (? surely?)

[madscientist]

thanks so far, are we closer to establishing a wiring diagram

could a knowledgable person , give me a quick summary of the " types " of miniature W&T machines , i.e. S, M <, L etc etc


thanks

Dave

[MRFS]

Bit late to the party - new smugphone so files and contacts shifted around, sorry for not replying sooner.

These are S pattern (S = Small, M = Miniature, L = Large)

*in the very broadest of terms* [1]

L/M are electrically identical, differ in size [LINE/LOCAL coils]
S = Z pattern swinging lock [LINE coils]

I will dig out my S pattern wiring diagrams. How good is your Spanish?

[1] there is a small group of people (most of whom are on this forum) who are assisting in writing the global history of staff instruments - it is not as straightforward as you may think.

[Mike Hodgson]

[1] there is a small group of people (most of whom are on this forum) who are assisting in writing the global history of staff instruments - it is not as straightforward as you may think.

When that is ready it should be a most interesting read, albeit to a rather small specialised audience, - any idea how/where will it be published, and whether anything similar exists or is being produced for tablet/token? I imagine the word patent will figure fairly prominently with consequent commercial ramifications, and if original patent documents are included that should be helpful to people like the OP who are struggling to restore surviving equipment.

[madscientist]

Bit late to the party - new smugphone so files and contacts shifted around, sorry for not replying sooner.

These are S pattern (S = Small, M = Miniature, L = Large)

*in the very broadest of terms* [1]

L/M are electrically identical, differ in size [LINE/LOCAL coils]
S = Z pattern swinging lock [LINE coils]

I will dig out my S pattern wiring diagrams. How good is your Spanish?

[1] there is a small group of people (most of whom are on this forum) who are assisting in writing the global history of staff instruments - it is not as straightforward as you may think.

I can handle Spanish , loads of spainish students about here !!

[MRFS]

[1] there is a small group of people (most of whom are on this forum) who are assisting in writing the global history of staff instruments - it is not as straightforward as you may think.

When that is ready it should be a most interesting read, albeit to a rather small specialised audience, - any idea how/where will it be published, and whether anything similar exists or is being produced for tablet/token? I imagine the word patent will figure fairly prominently with consequent commercial ramifications, and if original patent documents are included that should be helpful to people like the OP who are struggling to restore surviving equipment.

It's not the patent documents that are of most interest. It's the post-Mitchelstown discussions and alterations that are a *fascinating* read.