Conventional & Command Power Configuration

Your approach is correct.  Look for a switch than can handle the 10 amp load and voltage.  Lots of switches that match "20A 125V DPDT" on the river site.  I also find these at my local hardware store.

If you tie the transformer's grounds together AND verify the transformers are in phase (always a good practice), then a SPDT switch for the "hot" wire will work.  A 3-way light switch suffices and the parts to build a box for it are off the shelf.

@Kiana posted:

Conventional and Command Configuration

After several unsuccessful searches, I am posting this question for input solutions/experience on system configurations for selecting between Command and Conventional modes.

After years of conventional operation with PW equipment, I have recently acquired a Legacy Loco and intend to acquire others and am switching to Fastrack.

I have a Lionel KW Transformer for my PW equipment and with the Fastrack Legacy configuration I purchased a 180 Watt Powerhouse. I also have a Lionel 990 Command Set.

I am also aware of Lionel’s Powermaster.

My question is related to changing the operating (power) configuration from Command to Conventional and vice versa.

An obvious solution is to simply add a Lionel Powermaster. However, since my track layout is small and simple, I am considering a simple configuration using a DPDT (Double Pole – Double Throw) toggle switch to swap between the output terminals of the KW transformer and the TMCC Direct Lockon/Powerhouse.

To add clarification – I have attached a hand sketch of the proposed power configuration.

Questions:

Have others used this configuration?

I have not selected a DPDT Switch – Recommendations/suggestions welcome.

Are there reasons this is not a reasonable approach.

I have to ask why you are looking to turn the command on and off. Since the signal travels on the U post and is direct to the post it does not effect anything. You can also just unplug the command base and the command engine will go back to conventional. Very simple.

It can even be be simpler.  I largely ignore the difference between command and conventional, except in only one specific way.

Feed the track from the PowerMaster, fed by the PowerHouse.  Use the keypad on the Cab-2 to select the address of the PowerMaster, using the keypad to punch it in.  To run conventionally turn the knob up and down on the Cab-2.  As @ThatGuy implied make sure that the Base-2 isn't powered up at this point.

To go to command remove any conventional engines then turn the knob up to 100% (18 VAC), then power up the Base-2, then select your TMCC/Legacy engine using the keypad, punching in it's address, then turn the knob to get rolling.

No need for either SPDT or DPDT switches to select power feeds if you do it this way.

Mike

You don't even need the PowerHouse(or a DPDT - SPDT only is needed as "U" is common throughout). Here is how I power TMCC with a KW(or a ZW) to switch between command & conventional:

If you run MTH DCS, I'd lose the TMCC Direct Lockon, it kills the DCS signal.

In addition to allowing basic switching between command and conventional, doesn't using a PowerMaster offer additional benefits which a switching system like those above do not, such as:

a) allowing both command and conventional engines to be operated via one remote (the Cab 2) instead of having to switch between remote and transformer control - allows you to walk around and control the layout with the remote; and

b) layout can be powered by only one transformer/power supply (one of which you could sell to help offset the cost of the PowerMaster) and eliminates all the extra wiring  ?

I second what Mellow Hudson Mike does.  I run a legacy and conventional locos with the same setup.  Transformer feeding the Legacy Powermaster that is controlled by the Legacy base and remote.  Legacy Powermaster set to conventional.  I never use the Legacy Powermaster set to command mode.  The powermaster runs both conventional and Legacy/TMCC engines this way.

To run conventional, select the Legacy Powermaster "track" ID and use the remote to run the voltage to run the conventional engines. 

To run Legacy/TMCC, select the Powermaster and set track voltage high, then select the legacy/tmcc engine number on the remote.  This then runs the Legacy/TMCC engine.   No switches.  Just remember to set the voltage high for Legacy/TMCC engines.

Sometimes you just want to grab a handle and push a whistle lever.

Thanks for the enlightened and thoughtful responses provided. It has expanded my knowledge as I enter the world of Command Control using available modern power equipment from Lionel. Prior to this, I have run my limited Command Control equipment via the KW “set for 18 volts” checked by a Fluke multimeter with the fast-acting breaker in the circuit and the Legacy 990 handheld remote.

Although I currently do not have any MTH DCS equipment, I was not aware of the issue GRJ noted about the TMCC direct lock-on and “killing” the DCS signal - Thanks.

ADCX Rob summed up my reason for considering the DPDT configuration and not the Powermaster. There is significant nostalgia (for me) in keeping the KW in the mix when I run my PW Engines and Equipment. It surfaces fond memories of my “first Lionel Train Christmas”.

I had not considered Tracker John’s SPDT configuration and “phasing the power sources” which simplifies the circuit. However, I am a “belt and suspenders” guy based on my career experience and “Murphy’s Law” – if it can go wrong, it will.

Therefore, I will use the DPDT configuration now that it is confirmed, and I will not need to constantly monitor family interaction with the power sources.

On my layout I have many isolated power blocks each Zone fed by a rotary switch that switches between the two outputs of my Z-4000 transformer and two TMCC power houses to run conventional  locos  with the Powerhouses.   I later added TMCC to all the tracks with coupling capacitors to run in TMCC locos anywhere powered by the Z-4000.  Also siding power is switched on and off by the turnout control switches.   

This allows me to setup the blocks to run trains in conventional and TMCC at the same time.

Carl Tuveson
http://tuveson.com

So many ways to skin the cat.  On my former layout I used blocks with 3 position toggles (on, off, and Lockout Eliminator fed so conventional reverse units didn't cycle when parked in them) along with TPC-400's for Cab2 TMCC/Legacy and conventional ops along with locking DPDT toggles as appropriate to run Locomatic, AC with Lionel Sound Actuation buttons (never did tie in an ACG ACW/DH actuator), TMCC/Legacy, and DCC.  So many ways to enjoy your trains, so little time, and never enough $$.  

I also used 7A fast blow fuses and a Scott's Odds and Ends DTK-4Z spike protector (and still do).  However, I recommend using DCC Specialities PSX-AC's instead (I use PSX-1's on my HO tracks).  They provide incredibly fast-acting and auto-resetting short circuit and spike protection.  Funny thing, now while the S portion of my layout is greatly simplified (only AC or TMCC) I do have an ACG ACW/DH actuator included - albeit on a toggle for use with aptly equipped postwar locos, but otherwise out of that loop's circuit to avoid accidentally throwing 600Hz at engines with electronics in them (conventional AM, SHS, and L/AF).  Not sure that would actually do them any harm, just would rather not if I can.  Comments?

Carl - great to hear from you.  Curious about the coupling capacitors.  Why are they in your wiring?  They allow AC through but not DC, but there must be more to it than that.  Thanks.  

Dave,

Here is how I couple the signal to my layout.
http://www.tuveson.com/TMCCSig...l__distributioni.htm
You can use a .1uf instead of a .15uf if you can't find a .15
This is for a two rail S gauge layout.