Setting up block sections on my layout (old zw, d-264 dealer layout)

[Dobson]

Hello, thanks in advance for your help on this issue.

I have built a d-264 reproduction dealer display layout and I want to split the inner section into blocks.  One block for the uphill grade, another for the downgrade, and another for the lower section of my layout.  What I would like to do is set up each block to a post on my zw and cycle through the three posts meaning:  the outer handle will power the uphill grade, the section control the downgrade, and the third control the lower section of my track. 

An image of the layout can be found here:

http://rztrains.com/D264_Details.htm

My track is built with fastrack and i want to put in three block sections to achieve this.  Since my zw is powering the three blocks do i need to have "phasing" concerns?  Will there be bleed across the sections when the train is between sections or when the engine is in a new section and the passenger cars are in the previous block?

Is this safe to do?   and is this how it is done.....

A couple of additional notes.  I have the old zw, not the new one.

[lionelsoni]

It is not safe.  There will be a fault current every time your train crosses a block boundary.  The fault current, no matter how large, will never trip the circuit breaker of your transformer.

There are other, safer ways to do this if you're interested.

[Dobson]

I am interested in knowing safer ways if you could elaborate I would really appreciate it.

 

Thanks

[lionelsoni]

You can do it safely by powering the entire line from the same single transformer output, using resistors in series with the transformer to drop the voltage as needed.  A Lionel rheostat makes a very suitable adjustable resistor for this sort of thing.  However, resistors have the problem that the track voltage drops in proportion to the current drawn by the train.

I recommend instead using diodes to drop the voltage for the downgrade.  You can use individual diodes; but a neater way is to modify bridge-rectifier modules (like this one:  http://www.radioshack.com/product/index.jsp?productId=2062580) by tying the + and - terminals together.  This gives you two diode pairs that can each drop about .5 volt.  A few of these wired in series should give you all the speed control that you need.  You can have three (or more) voltage steps instead of two, direct for the up-grades, a diode string for the down-grades, and a tap partway down the string for the level track.