This is my name for "Bob's Really Useful Bus" that is "bus" in the electrical sense of wiring fed around a building.
This came up in this topic
http://thewoodhaven2.co.uk/viewtopic.ph ... =262#p2040 where Mark suggested I write it up.
I installed this in my house as we were doing a majors series of extensions 30 years ago so I've tried to bring it up to date and use a few more off the shelf items rather than the modules I made from discrete components.
The objective is to provide an alerting system available in as many rooms as required with low level discrete sounders for events without the need for a loud sounder that is audible all over the house. Over the years the functions have been expanded for all sorts of applications never originally envisaged.
The basic bus carries the telephone signal, 12v dc power and a 5th line which enables (sounds) low level sounders/buzzers mounted discreetly on the skirting or other similar locations. I had 6 wire phone cable in stock so there is a 6th wire as a spare which has been incredibly useful in retrospect. These days Ethernet cable is cheap and has 8 cores so that might be a better choice and provide 3 spares.
This is my BRUB wire assignment.
The telephone wiring pin numbers refer to the standard telecoms socket
The Sounder enable line deliberately has a line over the top following the logic convention signifying that a low voltage on that line will activate the sounders.
The power supply has been chosen as 12volts as fairly universal, safe and easily provided by package plug in units or Wall Warts.
Here are some basic minimal units on the bus.
The power supply has a 12v car lamp in series. This is a safety item as with all the wiring and connectors around the house a short is always possible. If this happens the systems will stop working and the bulb with light up, the rest of the time the current will be quite low and so the lamp possibly wont even glow.
I chose this as a readily available item that most people will have around or can get easily.
Wall Wart for Amazon or Ebay etc
I use a lot of these for example
http://www.amazon.co.uk/gp/product/B008 ... 8I5IJ46NPHThe are only 1.5amp but quite suitable for most installations.
The sounders can be found from all the usual suspects ebay, Rapid, Amazon. Best to buy just one to start with just in case you don't like the noise it makes - some buzz, some beep and some are quite high pitched.
They are all about a pound each. key search terms are Miniature, sounders, 12vdc, piezo etc you don't want the old fashioned electromechanical buzzer. These take too much current, don't make much noise, sound horrid and can create interference with other systems. Thankfully there are possibly not many around these days.
The telephone sockets are standard POTS* phone sockets available freely.
* Plain old telephone service
That's it for now. Next time there will be the tiniest little bit of electronic involved. So I'll be describing that and how it works in our system. It is very easy and no need to be afraid of gaining a little knowledge
Bob