Run TMCC and DCS at the same time?

The DCS Commander as I recall only outputs DC to the track.  While that's OK for DCS, TMCC requires AC on the track.  If you have the full TIU, it's quite possible to run them together, I do it all the time.

Ah, makes sense!  I assume MTH PS2/PS3 can run DCS on either AC or DC then?  And the TIU outputs AC?

@Loochy88 posted:

Ah, makes sense!  I assume MTH PS2/PS3 can run DCS on either AC or DC then?  And the TIU outputs AC?

The TIU on specifically the fixed channels passes whatever you put into the input of that channel. The fixed and variable channels are named for their function of what they can do to the power from input to output. Fixed channels cannot vary the power- what you put in is what you get out. Variable channels on the TIU can vary AC power (a limitation of the TIU design all versions- where the new WTIU can now vary DC on the variable channel).

As such, most people per the instruction manual and diagrams use fixed channel 1, which can pass AC or DC and whatever you put in- is what you get out.

@Vernon Barry posted:

The TIU on specifically the fixed channels passes whatever you put into the input of that channel. The fixed and variable channels are named for their function of what they can do to the power from input to output. Fixed channels cannot vary the power- what you put in is what you get out. Variable channels on the TIU can vary AC power (a limitation of the TIU design all versions- where the new WTIU can now vary DC on the variable channel).

As such, most people per the instruction manual and diagrams use fixed channel 1, which can pass AC or DC and whatever you put in- is what you get out.

So... if you are using TIU fixed channel 1 and passing AC power to the track, will MTH engines run their DCS features (ie, using ps2/ps3 and all its features).  Or do you need to be passing DC power to use DCS features?

@Loochy88 posted:

So... if you are using TIU fixed channel 1 and passing AC power to the track, will MTH engines run their DCS features (ie, using ps2/ps3 and all its features).  Or do you need to be passing DC power to use DCS features?

DCS is a high frequency digital signal that rides on top of the power in the channel- on AC or DC.

Given AC is the preferred power for most Lionel- MTH smartly made DCS both AC and DC compatible- so that both can be run on the same track, from the same power source.

@Loochy88 posted:

So... if you are using TIU fixed channel 1 and passing AC power to the track, will MTH engines run their DCS features (ie, using ps2/ps3 and all its features).  Or do you need to be passing DC power to use DCS features?

You get standard DCS operation, all the remote control features are available.

Again, let's go over this:

You have a mixed fleet of both Lionel and MTH engines. A lot of us do because this is the power of competition- features and quality of 2 or more companies competing forces some level of new never before made products and new features and quality.

You unfortunately started with the MTH DCS Commander- likely because of the lack of reasonably priced alternative control systems due to lack of supply and ever growing demand. This device has a lot of limitations or lack of features- one of them being it outputs DC track power that may be incompatible with a fair amount of Lionel TMCC era products.

You want to run both- and that certainly is possible and many of us do it because the 2 control systems can co-exist and work on the same track at the same time.

I highly recommend you sell the outdated and no longer supported DCS commander. It's mostly designed around the HO usage case and it's DC variable internal supply is just not good for O scale where inductive spikes from engines can absolutely kill a couple of components from voltage spikes. The firmware has not and likely will not be updated to similar features as current TIU and WTIU. You cannot even do a lashup with the commander. Sell it to someone who can use it and live with the limitations.

Not going to leave it at that. You still have a decent pile of equipment and there is an external scenario/solution that maybe works- passive mode. This is where you use your Lionel transformer and powermaster to power the track with a variable AC source. Key here is you put a 22uH inductor in series right at the hot output of the powermaster. That choke (inductor) blocks the high frequency DCS signal from being attenuated by the powermaster and transformer. You then build the simple circuit of capacitors and resistors to make the same DCS passive mode adapter circuit as used for the MTH DCS WIFI Explorer. This allows only the high frequency DCS signal to pass to the track, but blocks both AC and DC power between the track and your DCS explorer box. Granted, this is not the strongest signal path and solution, but does reuse what you have.

Previous passive topic about passive mode on the explorer- in theory also might work for the commander

https://ogrforum.com/topic/dcs-explorer-passive-mode

@gunrunnerjohn posted:

An interesting question, I wonder if a few external components might get the job done.  A hi-pass filter on the output to allow the DCS signal through but block the 60hz, and then just use a small transformer to power the DCS Explorer.

Something like this on the output of the Explorer to pass the DCS signal...

Note that I haven't tried this, but it's an interesting idea.

And my post in that topic

Vernon, that is super interesting! 

I dont have an understanding of exactly what is happening in that circuit, but I have the means to build it and try it.  I have a couple of questions.  Ive attached a picture of exactly what my setup would look like. 

In the section for the separation filter,  I have circled in green a portion where the positive and negative leads look like they connect, before and after the filter section... is this correct?  Or am i correct to assume that they should not come together here, as in my box in orange?  Can anyone clarify this?  Seems this would just short the circuit....

Also, the other thread mentions using a small 1a power supply to power the [in their case] Explorer.  In my case I power the Commander with a z750  75w  power brick when i am running DCS.  Any reason I shouldn't use this, and would want to go with a smaller power supply?

The separation filter must be as drawn- separate the 2 wires and connection points.
The drawing just has then close together but they are separate and do not physically need to be right next to each other.

Capacitors block DC, and further, can pass AC but becomes frequency specific- hence blocks 60HZ and yet passes the much higher DCS data packets frequency.

Since all the commander is doing is powering the internal electronics- you can use the Z750 Brick, or you can use a much smaller and possibly DC style wall wart of maybe 1A rating.

Thank you, I believe I understand now. 

I was just confused by the illustration and what looked to be a bit of wire shorting between the Hi and GND at each end of the filter. 

If I am understanding correctly (and I think I am), this is the same circuit.