power supply transformer wiring question

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I'm building this kit:

http://www1.jaycar.com.au/productVi...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

An externally hosted image should be here but it was not working when we last tested it.


It's a power up kit - where a master appliance switches on a slave when the master is powered up or down.

It has its own power supply, but I have come across something unclear. The schematic shows two 6.3V wires from the transformer to 4 diodes (bridge rectifier), however it does not show the 0V wire. The transformer supplied with the kit has this 0V wire, and I don't know if it needs to be hooked up somewhere, or if I can just plug it up.

0V wire in question is shown with a big black dot I added after scanning.

I have built power supplies before, so I'm not a total novice, but I had schematics that didn't leave anything out!

MY QUESTION: What should I do with the 0V wire from the transformer?
 

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The 2851 is a very common general-purpose transformer which can be used for a variety of applications, and normally has this centre tap. In the case of this project, they only needed a single 12.6V supply, so the centre tap wire is ignored. I am surprised though, that a spare isolated pad was not provided on the board, or at least mention of the wire in the text.

As Quasi says, just insulate and ignore it.

Cheers
Graeme
 
So the centre tap is there so that you have different voltage options?

UPDATE: I'm now going to add a key switch, so I can disable the whole audio system with a key! :)

Only thing is, the key switches don't handle much power, so I'm going to use a relay with the key switch controlling the power to the coil.

This is a nice feature to have in a diy system, since I can disable it if I'm working on something, so no one can turn it on! I've now made it user friendly enough that others actually CAN operate it now!
 
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