Different transformers on separate tracks, all running conventional and DCS via Double Pole - Double Through switch.

I have a very similar operation. I don't think you have missed anything.  I would just mention to use the best DPDT switches. I used some from china, and they shorted out my DCS.  Other than that I have/had no operational problems...

These switches are good quality from Grainger.

@RWL posted:

..

Each of these three three power supply bricks will be wired thru a DPDT switch.
One side of the DPDT switch will send power, from the brick, thru its respective transformer controller.
The other side of the DPDT switch will send power, from the brick, directly to and thru a DCS Remote Commander receiver box.

Power will only, ever, be sent to either the Controller or the DCS Remote Commander box, but never both.

How these will be opperated:
1. When running any Lionel conventional, Lionel Lion Chief, or MTH non-DCS locomotives, the DPDT switch will be set to send power thru the transformer controller.

2. When running any MTH DCS locomotive, the DPDT switch will be set to run power thru the Remote Commander receiver box.

..

To be clear, is this the configuration?

That is, one pole of the DPDT switches "hot" and the other pole switches "common".  And the "hot" and "common" outputs of the Controller and the mating DCS Remote Commander are always tied together (e.g., at the track).

If so, when in DCS Remote Commander mode, the track voltage "back-drives" the output of an un-powered Controller.  I'm not saying this is good/bad...just asking for clarification.

Thank you for that information.
I did see that in my original wiring plan, so I made a correction.

My current plan, and this is currently working on a single loop of track, is to run power from the brick directly to bot controllers.
Each controller, is then wired to one or the other outer poles of the DPDT switch.
The center poles run of the DPDT switch, go out the track.

While both controllers would always be powered, only one can ever be connected to the track.

If you take your layout and move the DPDT switch to the downstream side of the controllers, you will have the layout of what I am currently using.

Thoughts?

Right.  Without descending into the technical muck, I'm happier with the revised configuration.

As you say, the penalty is both controllers are powered at the same time.  I measured the idle power some time back.  Memory not so good these days but seems it was just a few Watts a piece.  Do not have a ZW so don't know its idle power consumption.

You can usually find a center-off 3-position ON-OFF-ON DPDT for the same price and form-factor as a 2-position ON-ON DPDT.  This can be handy to quickly disconnect any power from the track without pulling cables or what have you.

Why not just connect the DCS-RC directly to the tracks and run it in passive mode?  You can add a 22uh choke to the center rail feed of the transformer to improve the DCS signal strength if you have issues.  Then there's no switching of power.

Two things.

1. I think it may have been from a scope photo you posted, but I believe at full-throttle the Z-controller puts out a chopped sine-wave vs. a brick's unadultered "pure" sine-wave.  The degradation to DCS signaling may be small but it surely doesn't help.

2. The pesky 22 uH inductor/DCS-choke, if needed, can be a nuisance to find in small quantities.  For a 100 Watt brick you'd want one rated at least 5 Amps...and essentially double that for the 180 Watt brick (again, if needed).  By the time you account for shipping, you might be coughing up $5 each.  YMMV.

By The Way, my assumption is this:

While the 180-Watt PowerHoue does put out 180 watts, the voltage stays at a maximum of 18, making it safe to run the PH-180 direct thru the Remote Commander receiver box, as explained above, and to the track, for DCS operation.

Would this be a correct (safe) assumption?

@stan2004 posted:

Right.  Without descending into the technical muck, I'm happier with the revised configuration.

As you say, the penalty is both controllers are powered at the same time.  I measured the idle power some time back.  Memory not so good these days but seems it was just a few Watts a piece.  Do not have a ZW so don't know its idle power consumption.

You can usually find a center-off 3-position ON-OFF-ON DPDT for the same price and form-factor as a 2-position ON-ON DPDT.  This can be handy to quickly disconnect any power from the track without pulling cables or what have you.

The DPDT switches that I am using are good quality 3-position On-Off-On switches, from Grainger.com.
And, yes, the center OFF position is a very handy Power Cut-Off feature.

@stan2004 posted:

To be clear, is this the configuration?

That is, one pole of the DPDT switches "hot" and the other pole switches "common".  And the "hot" and "common" outputs of the Controller and the mating DCS Remote Commander are always tied together (e.g., at the track).

If so, when in DCS Remote Commander mode, the track voltage "back-drives" the output of an un-powered Controller.  I'm not saying this is good/bad...just asking for clarification.

Here is an outside the box question:
When placing the DPDT switch between the power brick and two controllers as shown, the risk would be, as Stan mentioned above, the back flow of current thru the off-switched controller.
This is why my plan is to move the DPDT switch to the 

Would it be reasonable to consider the placement of some sort of directional flow diodes in the two wires coming out of each of the two controllers to the track?

That would allow current to travel only out to the track, and not back to the off-switched controller.

I am a mechanical guy, and am not that well versed in the details of what this might entail, so I put it out there for discussion among those of you who are  much more electrically inclined.

Roger

@RWL posted:

By The Way, my assumption is this:

While the 180-Watt PowerHoue does put out 180 watts, the voltage stays at a maximum of 18, making it safe to run the PH-180 direct thru the Remote Commander receiver box, as explained above, and to the track, for DCS operation.

Would this be a correct (safe) assumption?

No, the DCS-RC is designed for a maximum of 6 amps through the internal PCB connections. 

@RWL posted:

...

Would it be reasonable to consider the placement of some sort of directional flow diodes in the two wires coming out of each of the two controllers to the track?

That would allow current to travel only out to the track, and not back to the off-switched controller.

...

Problem is AC or Alternating Current alternates the direction of current flow 60-times per second to and from the track so to speak.  It is true that diodes block flow of current in one direction...but to allow AC current to flow to and from the track you need to insert a pair of diodes.  Unfortunately in doing so those same 2 diodes would allow current to flow backwards, i.e., from and to the track.

Separately, getting back to what GRJ mentioned about "passive mode".  I'll elaborate later but here are some quick sketches.

The DCS-RC is rated for 6 Amps maximum current flowing thru it (from the input barrel-coax connector to the output banana jacks).  Isn't it "amazing" how MTH's Z-1000 brick's 100 Watts matches?! 

But a 180W brick could exceed 6 Amps.  Hence the passive-mode configuration.

Passive-mode is shown on the left with and without the controller.  If this is getting too weird just say so.  Otherwise we can continue the discussion!

@stan2004 posted:

Two things.

1. I think it may have been from a scope photo you posted, but I believe at full-throttle the Z-controller puts out a chopped sine-wave vs. a brick's unadultered "pure" sine-wave.  The degradation to DCS signaling may be small but it surely doesn't help.

2. The pesky 22 uH inductor/DCS-choke, if needed, can be a nuisance to find in small quantities.  For a 100 Watt brick you'd want one rated at least 5 Amps...and essentially double that for the 180 Watt brick (again, if needed).  By the time you account for shipping, you might be coughing up $5 each.  YMMV.

1. Connect directly to the brick.  You are correct, all the Z controllers are simple triac power controls. 

2. True, but is $5-6 really a major impediment?  If so, I'm in the wrong hobby.

The passive connection simplifies the connections, no switching needed, the DCS signal is there when you want it.

@stan2004 posted:

Problem is AC or Alternating Current alternates the direction of current flow 60-times per second to and from the track so to speak.  It is true that diodes block flow of current in one direction...but to allow AC current to flow to and from the track you need to insert a pair of diodes.  Unfortunately in doing so those same 2 diodes would allow current to flow backwards, i.e., from and to the track.

Separately, getting back to what GRJ mentioned about "passive mode".  I'll elaborate later but here are some quick sketches.

The DCS-RC is rated for 6 Amps maximum current flowing thru it (from the input barrel-coax connector to the output banana jacks).  Isn't it "amazing" how MTH's Z-1000 brick's 100 Watts matches?! 

But a 180W brick could exceed 6 Amps.  Hence the passive-mode configuration.

Passive-mode is shown on the left with and without the controller.  If this is getting too weird just say so.  Otherwise we can continue the discussion!

 

This is not getting weird at all.
I love to learn, and the answers are very good and clear.
I am also more than happy to continue this discussion, as it has opened up a whole new realm of understanding for me.
Again, this is my first true layout, and I want to build it the beast that I can, within financial reason.

I am very glad to learn about the 6 amp max for the DCS system, and am very glad I asked that question, or I may have caused some severe damage.

So, running in passive mode turns the DCS RC box into a signal entry point only, with power always coming from the transformer and thru the controller. Correct?

My Questions:
1) What does the 22uh choke do?
       Does it keep any of the DCS signal from back feeding to the controller?
2) Do the controllers effect the wave pattern in a negative way with regard to the DCS signal?
3) Do I need to measure where 16 and 18 volts, to the track, is on each controller, so that I can know where to set the controller for either Lionel-Lion Chief or for MTH-DCS locomotives?
4) Is there any way to limit the Amperage coming out of the 180 watt PH bricks?
       Probably not, but I have to ask.

No, passive mode connects ONLY the output terminals to the track, nothing is plugged into the input jack.  This allows the DCS-RC to inject the DCS signal onto the tracks, but no transformer current actually pass through the DCS-RC itself.

The 22uh choke in the transformer lead to the track keeps the transformer from attenuating the DCS 3.27mhz track signal.

The sawtooth waveform is not exactly good for the DCS signal, but many people do run that way.  In addition, when running DCS on the tracks, one would presume you'd be at full throttle, that yields close to a standard sine wave.

You can run DCS and LC/LC+ on up to 19 volts on the track.  No need to do measurements.

You can obviously put a smaller fuse or circuit breaker in series with the PH180 output, but I don't see a reason to do that.

John,

Very cool, so whenever running Lion Chief or DCS, just run the controller close to full power.
Yes, DCS box become just a place to inject the signal.

I have some of these chokes, that I ordered awhile back, for installing in the hot side of the transformer to track wiring, for just keeping the DCS signal clean. I think it is the same issue here, but just want to verify:

22uh 11A choke

Is this the correct choke for this application?
Would this work for both the ZW 180s and the Z-1000?

Correct that is a perfect match, AAMOF it's the one I use.  It will work for any transformer. 

Obviously, a pure sine wave is better for DCS, but if you use just the Z-1000 brick or have the Z-Controller full throttle, it'll be similar to a full-wave.

I guess I am missing something. How is the DCS-RC powered in passive mode?

Back fed from the transformer power in the track.

Passive mode through the track voltage on the output connections.  Same way you power TIU channel in passive mode.  In either case, no power in connected to the input power connections.

@gunrunnerjohn posted:

Correct that is a perfect match, AAMOF it's the one I use.  It will work for any transformer. 

Obviously, a pure sine wave is better for DCS, but if you use just the Z-1000 brick or have the Z-Controller full throttle, it'll be similar to a full-wave.

So John,
What about the wave form of the 180 PH bricks thru the ZW controller, with regard to the DCS signal?

The PH180 and the Z-1000 brick are both pure sine wave outputs, but the Z-Controller will hack either one into a sawtooth.

But what about the PH180 thru the XW Controller?
How does that effect the wave form?

Again, per your comment above regarding the Z-Controller:
When running at almost full power, does it really matter?
Is the wave more or less in tact?

I'm not sure what the XW controller is, but if you're talking about the ZW controller, it's the same basic principle of a chopped sine wave for anything but minimum power.  I don't have a ZW controller anymore, sold both of them.  However, here's my bench supply, a Z750 brick and a Z-Controller.  I start with the brick input to the Z-Controller and then the waveforms; min, middle, and max.  All were done with a 75 ohm resistive load.

Z750 Brick Output

Z-Controller Min Setting Output (75 ohm load)

Z-Controller Midrange Setting Output (75 ohm load)

Z-Controller Max Setting Output (75 ohm load)

I found some old waveforms from the ZW-C with PH180 bricks driving it.  Half throttle and full throttle with a 2 ohm resistive load.  Not super, but better looking than the MTH Z-Controller.

Then we get to the CW-80 and the reason why it's not an approved MTH transformer!  Imagine what the electronics was thinking when it saw those waveforms!

CW-80 at half throttle and full throttle. 

Geez, I go out to run some errands and you guys solve the world's problems!

As GRJ suggests, and as shown in his scope photos, the track voltage when the controller is set to full throttle (either the Z-controller OR the ZW) looks close enough to the un-adultered "pure" sine brick output.  Since you already have the Murata inductors, there's no out-of-pocket expense.  I'd just put them as shown above at the outputs of the ZW and Z-controller.

If for whatever reason you suspect the chopped/adultered voltage is degrading the DCS control (even with the 22uH inductor installed), you could try a simple experiment bypassing the ZW or Z-controller and feeding the pure sine brick voltage thru the 22uH inductor and into the track with the DCS-RC in passive mode as shown above.

Yes I did mean ZW. I bought one of your ZW's over a year ago. But again, what do these chopped  wave forms mean for DCS running?

The work on my layout keeps getting interrupted. A couple of years ago was was a layoff. Most recently, bladder cancer. Praise God it is non-muscel invasive, so there is treatment. I do have all of the Ross track, switches, and Rossbed to lay the outer loop, but I do have to add the L to my table, along with the transformer and control station. Oh, I also bought a 4' x 7' resin shed, which grew into a full blown construction and landscaping protect. I do plan to get back to itin the fall. I really do.

Don't feel bad, I re-injured my torn rotator cuff and I'm stalled on getting my layout track down.  I can't handle the sheets of wood to cut the elevations for the raised sections without help.  So, I'm a little stuck, I really want to get the track laid so I can move on.

If you want to stick your switch in, you could use it to switch in and out the transformer controller.  If you wire the track to the commons and the brick to one side and the output of the controller to the other side, you can have variable to run conventional, and pure sine wave to run command.  You can have the controller connected to the transformer, it just won't have any load if you're running right off the transformer.

@CAPPilot posted:

I guess I am missing something. How is the DCS-RC powered in passive mode?

That is a good question.  It is not obvious at all!

The DCS signaling circuit receives its power from either the input coax/barrel jack on the left OR the output banana jacks on the right.  In passive mode as is being discussed, there is no connection to the input jack.  So the DCS signaling circuit receives its power from the track voltage via the output banana jacks on the right.

The DCS signaling circuit injects the high-frequency command-control signals to the track on-top-of the 60 Hz track voltage power.  The DCS choke isolates this high-frequency control signal because it has a hard time competing against the transformer or controller. The actual technical explanation is somewhat tedious techno-babble so that's one way I like to think of it.

Thus, if operating the DCS-RC in "passive mode" you now must insert a DCS choke externally so that the DCS signaling circuit does not have to compete against the powerful transformer/controller.

Stated differently:

That is, in passive-mode you are effectively cutting the DCS-RC in half.  And you forgo the internal DCS choke.  So you must restore the function of the choke externally.

@stan2004 posted:

That is a good question.  It is not obvious at all!

The DCS signaling circuit receives its power from either the input coax/barrel jack on the left OR the output banana jacks on the right.  In passive mode as is being discussed, there is no connection to the input jack.  So the DCS signaling circuit receives its power from the track voltage via the output banana jacks on the right.

The DCS signaling circuit injects the high-frequency command-control signals to the track on-top-of the 60 Hz track voltage power.  The DCS choke isolates this high-frequency control signal because it has a hard time competing against the transformer or controller. The actual technical explanation is somewhat tedious techno-babble so that's one way I like to think of it.

Thus, if operating the DCS-RC in "passive mode" you now must insert a DCS choke externally so that the DCS signaling circuit does not have to compete against the powerful transformer/controller.

Stated differently:

That is, in passive-mode you are effectively cutting the DCS-RC in half.  And you forgo the internal DCS choke.  So you must restore the function of the choke externally.

Very good expatiation Stan,
You are an absolute master with the pictorial layouts.

Can you lay out the configuration that GRG proposed above regarding putting the switch back in, with the brick on one side and the controller on the other side? I think I understand, but a diagram would be very helpful.

@RWL posted:

...

Can you lay out the configuration that GRG proposed above regarding putting the switch back in, with the brick on one side and the controller on the other side? I think I understand, but a diagram would be very helpful.

I believe he means something like:

Notes.

1. The ZW controller is always powered...even when the DPDT is selecting the pure sinewave brick output to go to the track for DCS command mode.  Presumably the penalty is small - maybe a few Watts stolen from the available 180W.

2. The 22uH inductor is in-place for both DPDT selections.  The 22uH is benign in conventional mode.

3. The DCSRC is always powered.  Yes, in conventional mode the DCSRC will turn off/on every time you press the DIRECTION button on a conventional controller but this too is benign.

@gunrunnerjohn posted:

If you want to stick your switch in, you could use it to switch in and out the transformer controller.  If you wire the track to the commons and the brick to one side and the output of the controller to the other side, you can have variable to run conventional, and pure sine wave to run command.  You can have the controller connected to the transformer, it just won't have any load if you're running right off the transformer.

This is a compelling idea John, and I am very glad that you suggested it.

Lets see if I understand what you are suggesting:
1) One side would take the current from the brick thru the controller, then to the track.
2) The other side would take the current from the brick directly to the track, keeping the good sign wave form.
        2a) While switched directly to the track, the controller would remain powered, but would have no load.

The only difference between this and my original plan is that the DCS RC box is not in the switching system.
Rather, it is still in passive mode connected directly to the track, being back fed from track power, and with the 22uh choke in the Hot ware between the switch and the track.

QUESTION:
Does this not put the full amperage of the PH-180 into the track, like was the case with my original plan, there by endangering the DCS RC box PCB?
OR:
Does the passive mode method, somehow, protect the DCS RC box PCB from the full amperage of the PH-180?

There is no danger to the DCS-RC, it's internal circuits only take what power they require to operate.  If you were to power the DCS-RC the conventional way from the input jack, you'd still be delivering full power to it's internal circuits and to the output.  The only thing between the input and output jacks of the DCS-RC is a 22uh choke to prevent the input transformer from affecting the injected DCS carrier signal on the output.  The choke is invisible as far as 60hz track power is concerned.  By moving the transformer to the output jacks, we just added the 22uh choke so the transformer doesn't affect the DCS carrier to the tracks.

FWIW, this arrangement is the same for the full DCS TIU for passive mode.  After some testing, I determined that by adding the choke to the transformer feeds, the DCS signal on the tracks in passive mode was the same as in active mode.

@gunrunnerjohn posted:

There is no danger to the DCS-RC, it's internal circuits only take what power they require to operate.  If you were to power the DCS-RC the conventional way from the input jack, you'd still be delivering full power to it's internal circuits and to the output.  The only thing between the input and output jacks of the DCS-RC is a 22uh choke to prevent the input transformer from affecting the injected DCS carrier signal on the output.  The choke is invisible as far as 60hz track power is concerned.  By moving the transformer to the output jacks, we just added the 22uh choke so the transformer doesn't affect the DCS carrier to the tracks.

FWIW, this arrangement is the same for the full DCS TIU for passive mode.  After some testing, I determined that by adding the choke to the transformer feeds, the DCS signal on the tracks in passive mode was the same as in active mode.

As I suspected, passive mode, while taking in only the current that it needs, does not see the full amperage from the brick.
This is really awesome.

I get what I wanted, in the first place, by having the un-chopped wave forms going directly, from the brick, to the track, when in DCS mode, while still protecting the DCS RC from the full amperage of the PH-180.

There is no difference, in practice, from me original layout. I am just moving the DCS-RC box from, in line from brick to switch, to out on the actual track (i.e. passive mode) and with the 22uh choke in the hot wire from switch to track.

Thank you so much John for suggesting this.
Thank you Stan for making the diagram.

If I had not gone thru this exercise in verification of my plan, here in this post, I might have done considerable damage to my DCS equipment.

Thank you both again.
Roger

Don't know if you'd have cooked anything, but maybe.   However, given your requirements, this seems to be at least on good solution to achieve your goals.

just to be clear:

I have one more question:
I will have the commons going out and into Hot and Ground terminal strips.
Each pair of wires will go out, from the terminal strips, thru a two position (On-Off) switch to the blocked sections of the track.
This being the case, my understanding is that the DCS-RC box would be connected to the commons, or to the two wires going out, from the commons, to the Hot and Ground terminal strips.

Is this correct?

@gunrunnerjohn posted:

Don't know if you'd have cooked anything, but maybe.   However, given your requirements, this seems to be at least on good solution to achieve your goals.

No. I have done no damage yet, as I have only been running one loop of track, so far, and have been powering it with a Z-750, which I have recently upgraded to the Z-1000.

The PH-180s have, not yet, been introduced to the system.
And now I know how to do it safely.

I'm not sure I follow that, I need diagrams too.   Seriously, just follow Stan's diagram, that's exactly what I was talking about.  The two wires going to the TRACK go to whatever distribution system you have for wiring the track.  Note that the DCS-RC will only drive a limited amount of track, it's designed for starter systems, not full-blown layouts.  I suspect by the time you get to 80-100 feet of track, you may start having DCS signal issues.