Old Domestic Servants/Butlers call system

[123]

I'm just in the process of starting a rewire in a 1930's house, and the new owner has asked if the old servant/butler call system could be put back into service. It's not functioning at present, but I've not looked into any detail as to why. Anyone familiar with how they are supposed to work?

 

[snowhead]

There's a larger one for sale on ebay with photos of the back.

Pardon our interruption...

Looks like it's solenoids that wave the flag, and maybe ring a bell outside of the box.

Probably low volts D.C with a battery somewhere nearby and push buttons in the rooms

 

[littlespark]

It will be fairly simple to work out. Does any of it work, or still wired up?
Normal push button like a doorbell push in each of the rooms, 2 core bell wire back to the bell box.
Might need to determine if AC or DC, but will be ELV.

Each button and signal in parallel, and one bell in series with the return.

 

[123]

There's a larger one for sale on ebay with photos of the back.

Pardon our interruption...

Looks like it's solenoids that wave the flag, and maybe ring a bell outside of the box.

Probably low volts D.C with a battery somewhere nearby and push buttons in the rooms

View attachment 98259

Push buttons in the rooms definitely. Not sure on the bell or battery - will have to have a look when I'm back there next week.

 

[123]

It will be fairly simple to work out. Does any of it work, or still wired up?
Normal push button like a doorbell push in each of the rooms, 2 core bell wire back to the bell box.
Might need to determine if AC or DC, but will be ELV.

Each button and signal in parallel, and one bell in series with the return.

Doesn't work but I've not looked into why - I'd assume it's still all wired up as much of the property hasn't changed since it was built in the 30's. The push buttons are still in place, as is the box pictured.

 

[timhoward]

Found this on the interwebs:



Nothing to it really, the only mystery is what kind of supply voltage it needed.
In the absence of any other clues I'd probably start experimenting with a 9v battery.
The solenoid voltages are not going to be super-critical especially given the momentary nature of their use, and the bell could always be replaced with a known voltage unit.

 

[OnlQQker]

Reminds me of the bell systems they used to have in some of the National Trust houses I used to look around

 

[littlespark]

Reminds me of the bell systems they used to have in some of the National Trust houses I used to look around

View attachment 98264

View attachment 98265

Are these electrical, or wires and pulleys?

I’ve seen both types in old farm houses. None ever worked.

 

[littlespark]

Found this on the interwebs:

View attachment 98262

Nothing to it really, the only mystery is what kind of supply voltage it needed.
In the absence of any other clues I'd probably start experimenting with a 9v battery.
The solenoid voltages are not going to be super-critical especially given the momentary nature of their use, and the bell could always be replaced with a known voltage unit.

The voltage won’t be as exact as it would be nowadays…. Will possibly work from 9 up to 24v

 

[123]

Well got a better look at this today. The existing cabling is goosed. There is also no longer an external bell, that seems to have left some time ago along with the power supply. Everything inside the box pretty much looks like @snowhead post #2.

I'm assuming that gravity is what makes the flag drop down again?

 

[freddo]

The voltage won’t be as exact as it would be nowadays…. Will possibly work from 9 up to 24v

Some small setups use even less. I've seen 2 systems designed to use 3 1.5V flag cells, another used 5.

I'm assuming that gravity is what makes the flag drop down again?

The flags on these are usually just pulled by the electromagnet when the call button is pushed, then when the button is released the flag springs back and continues to swing for 30 seconds or so. Posher models the flag drops down permanently and a button has to be pushed to activate a separate reset electromagnet.

I have a rather old book here called 'modern electric wiring' that has a large section on these systems. I'll scan the pages in in the next day or so and post them here. Quite an interesting book, I'm not sure of it's age but it mentions tungsten lamps as new technology, and has information on many other types of lighting including those cool Nernst lamps and Moor light tubes which I've never seen in real life but wish were still being installed.

 

[Lucien Nunes]

Also consider that the annunciator coils are more or less constant-current-driven by the bell in series, so the battery needs to be matched to the bell voltage and its current to the minimum working current of the annunciator. I agree that this would typically have been less than the 9V mentioned further above. In the early days of electric bells, a common power source would have been Leclanché cells - liquid-filled glass jars - where a smaller number of larger cells was preferable to a larger number of smaller cells. Then as mentioned when dry cells took over these would often have been a battery of Flag / Type O or similar. The archetypal small bell battery was probably the 126 which was 4.5V.

 

[UNG]

I did some work on a house back in the late 80's / early 90's that had a call panel and the power supply was hidden away in one of many secret cupboards and alcoves built into the wooden wall paneling

 

[freddo]

I've scanned in the section of the book to a PDF: