Modernising a Domestic Servants call system

[Gabler]

I have a house built around 1900 with a servants call system. The indicator/bell unit is similar to the one shown in the attachment and the push buttons are all in place. Internal wiring of the unit is complete and local tests prove it all works. Unfortunately, all the wiring from the push buttons to the unit is not and it would be a major undertaking to rewire. I have been retired long enough to be out of touch with modern advances in wireless switching so my question is "can anyone suggest a wireless means of operating this system and the hardware for it and to keep the original push buttons"?

 

[littlespark]

Ive studied plenty of these in non working state, and would love to get the time to fix one up, but none of the customers are bothered....

The trouble is, that the power supply to this would be an old bell transformer, positioned at this end.... There is no power at the buttons if the cables are damaged.

There are wireless switches on the market that can be battery powered or kenetic operation that dont require power, but you would need a reciever for each button.... and an enclosure to hide them in.., they wont fit inside a unit like this.
Not a cheap solution

 

[Avo Mk8]

My first thoughts for this were toy/model radio control modules, as they can be obtained with 8 channels or more, but all the 'off the shelf' kit typically relies on a single hand held transmitter, and you effectively need nine of those!
You can purchase toy/car/drone tx and rx pcb's individually, but I haven't seen anything with enough channels so far!

If you keep Googling for long enough, you might find a remote control setup with a sufficient number of transmitters to cannibalise!
Eg: Système de commutateur de télécommande sans fil, émetteur + récepteur/lampe/porte de Garage/volets/fenêtre, 3000m DC 12V 10A 12 CH 12 CH RF - AliExpress 44 - https://www.aliexpress.com/item/32981146035.html?

Someone with an intimate knowledge of model radio control, or how to do it with a Raspberry-Pi etc, might be able to help!

Note that just buying 9 single channel remote controls won't help unless they can be individually paired, and have enough independent channels. Those that just rely on sending a carrier frequency will likely operate multiple receivers, if not all of them. In other words, pressing any single button could trigger all the receivers and hence all the flags!

 

[timhoward]

Tricky one.
If you don’t mind involving a micro controller you could do something along these lines:

RF 433MHz Transmitter/Receiver Module With Arduino | Random Nerd Tutorials

This post aims to be a complete guide for the popular RF 433MHz Transmitter/Receiver module. I’ll explain how it works, show some features and share an Arduino project example with code and schematics that you can take and apply to your own projects.

randomnerdtutorials.com

And use the Arduino to control relays to activate the indicators.

You would need a DC power source at each call point though.

There are switches that get power from kinetic energy and send an rf signal but they won’t allow the use of the existing call points without some mechanical solution.

You could cook up something with these:

Self-powered Wireless Switch (433Mhz)

Remote controllers can be seen everywhere, and most of them are inseparable from a battery. However, we often encounter problems when using batteries, for instance, it can be troublesome to replace batteries, batteries are easy to corrode in a humid environment, and waste batteries may cause...

thepihut.com

Gravity: Digital Wireless Receive Switch (433MHz)

When building a project that needs to transmit simple signals wirelessly, have you been bothered by any of the following problems: Bluetooth's cumbersome AT command configuration and high cost, Wifi's signal limitations and high power consumption, IR emission angle and inability to penetrate...

thepihut.com

And a pi to receive the signals and trigger relays.
But it’s all a bit involved and would need some electronics and some programming experience.

 

[Avo Mk8]

At a simpler DIY level I see Sonoff do an 8 channel transmitter, and 4 channel receivers, and they are reasonably priced compared with other light switch type options.
So eight of these(!) and two appropriate receivers (below)

How to use RF 433MHz remote control to intelligentize your devices? - SONOFF Official

sonoff.tech

And two of these: SONOFF 4CHR3/PROR3 - 4 gang 433Mhz RF remote WiFi smart switch - https://sonoff.tech/product/diy-smart-switches/4chr3-4chpror3/

Chinese versions:
SONOFF-Télécommande RF pour maison intelligente, RSafe33Inter, 8 touches, 433MHz, TX, 4CHPROR3, RFR2, iFAN04, D1, RF BridgeInter - AliExpress 13 - https://www.aliexpress.com/item/1005006806690831.html?

Macoff-Joli WiFi 4CH PRO R3, 4 canaux, montage sur rail DIN, télécommande sans fil pour maison intelligente, minuterie DIY, fonctionne avec Alexa - AliExpress 44

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Caveat - needs checking that these will actually do what you want, but at first glance, assuming each remote can be fettled to connect one of its buttons to each of your old-school bell pushes, it potentially could do the job (for 8 of the 9 flags)

 

[Gabler]

I am most grateful for all your contributions. There is merit in most suggestions and I realise that distance and obstructions may scupper most of them. The Sonoff products look promising but I have much studying to do.

 

[davesparks]

Yes it absolutely can be made to work, it just depends on how much money you want to spend on it.

 

[Gabler]

Yes it absolutely can be made to work, it just depends on how much money you want to spend on it.

Fair point, but you can't take it with you and I have set myself this project. The bell and indicator box is over 120 years old and it all works except for the wiring from the call buttons. I hope to get some wiring to some buttons but I know others will be too challenging.

 

[Mike Johnson]

Most RC Model systems work on a bus system now days so minimal wiring, Transmitters are available up too twenty channels and more so that is not the problem, converting the signal too operate the flags also not a problem with mini servo's, the problem is getting the call buttons to interface with a Tx, someone with electronics knowledge could possibly take a Tx to bits and hide the channel operating button behind the call point, but distance cold be the downfall.