Walsall iron light switch

[unionworkeruk]

"there is the issue of earthing that metal"

Yes, that would work, but there is the issue of earthing that metal - they just didn't bother earthing the metalwork in those days . I suspect, you might even be able to use that switch as a proper replacement, in your cast-iron enclosure.

Couldnt I just fit the earth wire in a choc bloc or similar ?

 

[bernardgreen]

This might work.

 

[JohnW2]

50v Uniselector, as used by the GPO / BT back in the day. Each pulse moves it onto the next contact set.

Indeed - that's the sort of thing I meant by a 'stepping relay'. However, that would require the switch to be a 'momentary action' one (which it isn't) and there might also be a need for some rectification, since I'm not sure whether there is an AC equivalent of such a uniselector.

Kind Regards, John

 

[Harry Bloomfield]

In the bad old days, when your original switch was used in a wooden back box, the botch to earth the switch involved wrapping an earth wire under the head of one of the side fixing screws - the screws fixing it to the back box.

That 2 way switch on Ebay is a completely different style of switch. Rather than being fixed back through those metal lugs, the 2 way switch would have been surface fixed to a wooden pattress with a couple of wood screws through holes in the porcelain - so no obvious way to attach an earth to the metal.

My best suggestion would be to consider you might have to solder an earth lead somehow, then use a connector to connect it to your earth wire. Your ebay 2 way switch pre-dates my experience, so I cannot even remember what the look like under that metal dome cover.

 

[unionworkeruk]

under that metal dome cover.

 

[Harry Bloomfield]

under that metal dome cover.

Thanks, it should be possible to find a suitable surface to solder an earth wire to that. From memory, the switch frame/wings are fixed to the porcelain by a couple of screws coming up from the back of the porcelain, you can just make out the ends of the screws, in those wings. The screw heads were then sealed in place by some sort of very hard resin.

 

[Harry Bloomfield]

This might work.

That an interesting one I have never seen before!

 

[JohnW2]

This might work.

Indeed - and that would avoid any appreciable energy 'wastage' due to the relay coil being energised for appreciable periods of time. However, for a proportion of the time (depending on switch settings) current would be flowing through one or both of the capacitors, even if the light was not on - minimal energy usage, but perhaps not the nicest of situations.

... and, of course, you are introducing components (capacitors) which are quite likely to fail (potentially with a bang and a flash!) far earlier than switches or relays normally would.

Kind Regards, John

 

[SUNRAY]

This might work.

View attachment 169645

You're giving your age away Bernard
Yes it does work but I haven't seen that for years. Judging by the big black marks and sticky confetti inside the cast iron enclosures of yesteryear I think I know why it went out of fashion. Modern components are of course more reliable.

 

[FrodoOne]

I have just bought an old Walsall one gang light switch. I want to replace one of the switches on a two way circuit with the Walsall. The wires for the Walsall are fitted thro the conduit behind the switch you can see in the photo, under the iron plate .

Would it be possible to replace the one way fitting with a two way and fit it to such an old switch although I cannot see any on sale. I am not an electrician so happy to pay one if needed.

Apart from the earthing of the metal-work, it appears that what "unionworkeruk" requires is a SPDT switch mechanism which will replace the SPST (porcelaine) mechanism in the "old Walsall one gang light switch".

The two main requirements of any new "mechanism" are that
it will fit in the space available and
it has a projecting "toggle", which may be operated by the switching lever in the metal cover of the Walsall "switch".

Modern "mechanisms" are available with such "toggles" added - to be used in "heritage" restorations.
For example, the ones shown here https://www.classicswitches.com.au/polished-brass-toggle-switches-power-points/
It would be possible to take the first of these (Classic 1 Gang Flat Plate Heritage Light Switches - Brass Toggle with Brown Base),
cut the mounting plate to fit the space involved,
drill two holes spaced as for the two existing mounting screws and
place the modified "plate" in position.

(The mechanism inserted in the mounting plate is a SPDT unit (as are [virtually] all Australian light switches.
One may find that the "Polished Brass" of the mounting plate is just a layer of "brass" on a plastic plate.)

Of course, there are probably UK heritage/classic switches of this type which could be modified in a similar manner.

 

[bernardgreen]

You're giving your age away Bernard

Wish I could, it would be great to be 30 again.

I didn't know the idea had been used in the past.

 

[SUNRAY]

Wish I could, it would be great to be 30 again.

I didn't know the idea had been used in the past.

Oh Yeaaaahh they were used in intrisically safe locations, I think I want to say they were in a cast Iron or possibly diecast ali enclosure about 9x9x6" with a big red lens on the front, inside was a 80V 5W bulb (Very slim chance I may still have one) a 3000 type relay with huge contacts, 2 wacking great big waxed paper caps (4 to 5"x 1.5") and a terminal strip. There were also a couple or more resistors.
I want to say the name cast in the front was 'fielde'.
Every one I went in had a puddle of wax, a blown a cap and filled with the paper and ali dust.