help: wiring #452 lionel dual signal bridge for independent controls

[steelervol]

So are you saying that if I remove the insulator of the ground rail between both loops, the fact that both loops are running on the same ground connection, should fix the problem?

 

 

[lionelsoni]

The Z-4000 manual is rather vague about whether the black terminals are actually connected together inside:  "...Each connector is color coded, BLACK for ground (-) and RED for positive (+) connections. The top row of connectors are BLACK and act as common ground connections for each output, while the bottom row of connectors are RED and provide the positive connection for each output.  Connect the BLACK or ground terminal to either outer rail of the track and the RED or positive terminal to the center rail of the track...."

I have trouble with the nonsense phase that I have emphasized.  A common node must be common to more that one circuit--that's what the word means.  Furthermore, the + and - terminology gives me no confidence that the author knew what he was writing about.

Then there's the stern "Note: The owner should not, at any time, attempt to connect or short any of the voltage outputs together in an effort to gain more power output. If the user attempts such a procedure, the Z-4000 may become permanently disabled." This could make you fear that if you assume that the black terminals are common and connect them together, your Z-4000 and its warranty are toast.

I agree that the black terminals are almost certainly all connected together inside and are a true common.  But I can see that he has good reason to worry about assuming that.  Do we have anyone here who dared to disobey the "WARNING:...To avoid the risk of electrical shock, do not disassemble the unit. There are no user-serviceable parts inside...."?  Can you verify that a common exists?

[ADCX Rob]

With such a straightforward layout/power scheme, why are you going to such lengths to avoid using the common ground?  The outside rails of each track loop are already connected at the transformer internally.

[steelervol]

I have a double track section, with each track a part of separate loop.  Each loop is powered separately by 2 different sides of a Z4000.

both loops have both rails insulated from each other.

On top of each end of this double track section, I have placed a #452 Lionel Dual signal bridge.  Thus, there are 2 signal bridges which appear to be circa mid 90s.

I have figured out the logic of placing an insulated track section at either end of each track section to get the going/coming to be green/ red between both signals on each track individually.

But, my problem is that it appears that the ground is common to both sides each signal bridge.  So the pair of signals on each bridge is not electrically independent.

Is there an "easy" way to insulate one of the signals so that it operates independently of the other on each bridge?  or is there a manufactured signal bridge out there that is made with the signals already independently wired?  or is there another way for how the track is wired to overcome this obstacle?

thanks!

Steelervol