E-Z Command Alternate Power Sources

[Jim Banner]

A previous discussion on powering the E-Z Command from either its own transformer or from a different transformer via a dc power pack left open the question of what would happen if you used both transformers.  Analysis of the partial schematic of the E-Z Command that I drew up some time ago and of the schematic of the 44212 dc power pack that Joe Satnik drew up recently led me to believe that if both transformer were used, the E-Z Command would preferentially draw power from its own transformer.  The transformer connected to the 44212 would supply only a small amount of power to  the 44212 to allow it to send a dc signal to the E-Z Command.  Tests just performed confirmed exactly this.

I used a 30 ohm, 25 watt precision power resistor as a load and used a clamp on ammeter to confirm which transformer was supplying the current consumed by the load.  When the E-Z Command was used alone, its transformer supplied the power.  When the E-Z Command was used without its transformer but was connected to the 44212 and its transformer, the 44212's transformer supplied the power.  And when both transformers were used and the 44212 was connected to the E-Z Command, only the transformer connected to the E-Z Command supplied power to the load.

The significance of these findings is that if you want to use your 44212 power pack to power turnouts, building lights, and other accessories without robbing power from your tracks, but you still want that extra control and/or extra DCC address, you can do so by using the two transformers.  Which of your two transformers powers the 44212 and which powers your E-Z Command does not matter - they are identical.  The E-Z Command manual does not say you can do this.  More significantly, it does not warn you not to.  Perhaps they don't tell you to do this because there is one idiosyncrasy that you need to live with.  Once you have connected your E-Z Command to your tracks and to your 44212, you are left with the question of which to power up first - your 44212 or your E-Z Command.  It turns out that it does make a difference.  If you power up the 44212 first, it will automatically take over control of analogue locomotives and free up address 10 for DCC locomotives.  But if you power up the E-Z Command first, then it will not relinquish address 10 to the 44212.  This means address 10 will still control analogue locomotives and not be available as an extra DCC address.  And it means the 44212 will just be along for the ride - it will not control anything.  I cannot guarantee that your setup will cycle exactly the way mine did but it makes sense that something in the power-up sequence has to decide how to use address 10, and most likely that something is the microprocessor or PIC controller that controls just about everything in your E-Z Command.

While doing the above tests, I was also able to confirm that both methods (address 10 or using a 44212 power pack) used zero stretching to power analogue dc locomotives. 

[SvFiat]

Jim, Here's another thought on that. When i first got back into model trains about a year ago, I bought 2 Santa Fe DCC train sets which came with 2 engines and the Alaska train set. Now i had a total of 4 DCC engines, one DC engine, 2 10 address controllers, one DC controller and 3 one amp wall warts.
The first wiring setup was wall wart to the DC controller to the DCC controller to the track. That gave me the use of all ten addresses using both controllers.
Somewhere along the line I needed more power due to the usual add on for lights, turnouts, ect. that I was bleeding off the accessory tap on the DC controller. So I wired the 3 wall warts in parallel keeping the white traced wires together giving me a total of 3 amps. Worked just fine.
I've graduated to a Dynamis and a 5 amp power booster and many more engines but I still use those 3 wall warts and the DC controller for all the accessories.

Have Fun

[Jim Banner]

Putting transformers in parallel requires that both the inputs and outputs be in phase.  Keeping the white striped wires together keeps the outputs in phase.  Plugging the three transformers the same way around into a power bar will keep the inputs in phase.  Plugging two transformers into a single wall outlet with one transformer up and the other down will spell disaster unless it is a split outlet, as often found in kitchens.  If you are using a split outlet, then you must plug one in one way, and the other the other way.  Plugging the third transformer into a different wall outlet is a crap shoot.  If it phased the same as the first outlet(s) then no problem.  But if it is on the other side of the electrical supply, bye bye transformers. 
Bottom line, if you insist on paralleling their outputs, plug all the transformers, same way round, into a power bar.  Then match their outputs.

_{Note that the above is for transformers.  Paralleling the outputs of dc power packs is a whole different ball game.}