Tuesday, 17 July 2012

Temporary 12v Supply

We now have a temporary 12v supply at either end of Waiouru.  In the cratch is a borrowed power pack which I have temporarily wired into the water and shower pumps via a couple of switches.  It will be interesting to establish how long the power pack will last before requiring recharging.

The power pack

The temporary switches

At the rear of Waiouru There is a temporary 12v supply consisting of an old 12v lead acid battery and 3 stage charger in the engine bay.  I’ve connected it to the fridge and gas oven wiring via a fuse.  This is certainly NOT elegant wiring and we are very keen to replace it by commissioning the Empirbus conrol and distribution system.

Today I started reading the Empirbus manual.  All 77 pages!  Well I got bored (it’s a man thing!) and started to play with a copy of the configuration file.  Actually I think I managed to work out how some of the configuring is done!

The software program is now installed on the laptop and the original configuration file programmed by Mark Johns at Atlantis Marine was loaded.  However there have been a couple of changes and additions to the wiring so the configuration file needs amending.

We are fitting a terrestrial TV aerial on Waiouru and it has a 12v signal amplifier.  This wasn’t in the original specifications.  After ready about TV signal boosters I understand the booster should be as close to the aerial as practical.  The closest I can fit the 12v amplifier is in the top of the starboard (right) wardrobe in the bedroom.  There is an Empirbus “node” in the wardrobe under the gunwale and it has a spare “output” connection.  So I’ve run a short wire from the node connection to the amplifier.  Now I need to configure the switch.  I want to be able to turn the amplifier on/off from beside the bed as we have a 12v TV in the bedroom.  The same aerial supplies a signal to the TV and media tank in the saloon.  So I need another switch in the saloon.  I also want to ensure the amplifier is turned off when we leave the boat unattended so it needs to be linked to the main isolation switch in the rear cabin

The following is a screen dump of the configuration. 

The detail is slightly hard to see so I’ll explain the arrows.

  • Left arrow – Name of Consumer (the TV amplifier)
  • Right arrow – The connection on the bow node (module D position 7)
  • Centre 3 arrows – Pointing to the switch connections (bedroom switch, saloon switch & master isolation switch).

The amplifier isn’t physically wired to any of these switches.  The nodes (computers) “talk” to each other.  When the saloon switch is pressed the middle node “tells” the bow node to supply power to the TV amplifier.

This next screen dump shows all the connections for the 12v master isolation switch.

The left arrow points at the name of the switch (master isolation) and the right arrow points at the physical location in the boat.  In this case the switch is No7 on the rear membrane panel.  You might also have noticed all the other connections highlighted in light green.  These are all the other input and output connections that can be controlled by the main isolation switch.  By not having a physical link (wiring) between the input devices (eg, switches) and the output devices (power consumers) it is possible to reconfigure the relationship between switches and consumers by amending the software.

I suspect this might sound rather complicated?


Paul said...


Meant in the best possible way, your mad mate, but good on ya for doing something different, very different on a narrowboat

Tom and Jan said...


Paul, canbus technology is now in your new car and is entering the home. The switches on Waiouru are actually for a 240v house canbus system and have been modified for 12v DC.

Anonymous said...

yep definately mad! should keep it simple, glad I'm not the only one who was thinking that! lol

Davidss said...

I'd say it is simple, but it is also a concept and method which most of us were not brought up with, which in turn means learning a new concept at a time in our lives when we don't normally need to concentrate so hard, for so long.
Brain cells only continue to work if they are kept exercised.
We are not asked to learn about how the node computers talk to one another, merely accept that they do, and show we understand the results by configuring the system.

Put it another way, whatever wiring system is used, hard-wired or Empiribus, the user has to understand that the amplifier needs to be 'on' when any TV is on, and that power to those switches will be via the master switch.
Once the user has grasped that essential knowledge it is implemented EITHER by running lots of wires behind the walls, OR ticking a few boxes in a grid displayed on a PC screen.

This example shows how simple configuration changes are when adding kit, how little hardware changes need to be made, and justify any additional set-up costs.

If someone can handle the Ben Harps of this world, this is 'falling off a log' simple.

IMHO :-)

Tom and Jan said...

Yes, it's simple.... But imagine if Ben Harp had wired the system. Turn on the galley lights and the toilet would flush. Press the shower pump switch and the navigation lights would illuminate! LOL