Little ZW Help

[lionelsoni]

I almost forgot to mention, that carbon has a negative coefficient of resistivity with temperature.  So, as the transformer heats up, the resistance of the rollers actually decreases.  Since the current is determined by the load and is more-or-less constant, the power dissipated in the rollers due to that current drops instead of rising.

[lionelsoni]

The circuit for the train is through the outside rails and the center rails.  The circuit for the accessories and turnouts is through most of the outside rails and the control rail.  The train's wheels just act as a switch to connect the accessory to its power supply through the control rail to the other outside rails.  The only thing that the two circuits have in common is--the common, that is the bulk of the outside rails.

Imagine that you took a flashlight and made a single connection between one side of the flashlight battery to the outside rails of your layout.  You wouldn't expect any effect from that.  Both layout and flashlight would still work just fine and not interfere with each other.  It's the same idea.

The voltage difference between two AC voltages at the same frequency but opposite phase is of course the sum of the individual voltages.  Something similar happens with voltages of different frequencies, for example, 50 Hz and 60 Hz.  If our forum friends in Europe were to try using 60 Hz, which is expensive for them to produce, just for running the trains and their usual 50 Hz for accessories and turnouts with control rails, there would also be a voltage difference.  It would be not the sum of the two voltages but the square-root of the sum of their squares, no matter how the transformers were plugged in.  Nevertheless, it would work just fine.

Likewise, it works to mix AC and DC, and various waveforms other than sinusoidal AC, like the stuff that comes out of a CW80.  I personally use a bizarre half-wave DC, with the two halves of the AC waveform controlled separately to run two trains (a low-tech TMCC), and DC for turnouts.  No problem.

[MartyE]

I always found that statement to be questionable.  Can you explain to me why they don't have to be.  Seems to me there would be point where the differnce in phase could present a large difference in potential that could cause issues.  The problem would not really exist until the two are tied together bt the activating train.  Maybe I'm missing something.

[lionelsoni]

Transformers used for turnouts and accessories do not have to be in phase with the transformer powering the track.  Having them in phase is harmess, if you want to go to the trouble.

[MartyE]

Yes it is possible to use another transformer just for switches and yes you would need them in phase.  This way too you can have a finer controll on the voltage while providing more juice for the trains...

 

As far phasing goes...       http://www.martye.com/TipsandTricks/TipsandTrick2.htm

[proactive]

First, Thanks for everyone helping me with this.

I went downstairs and started removing bulbs and realized for a few switches I have multiple controllers.  I removed 38 bulbs from swithces and controllers, however I count 4 additional bulbs in bumbers.  I also have about 60 cars on the track on turnoffs, 5 of which light up.  All engines light up.  After removing the bulbs, I see a great difference, much better but I still notice one section worse that others.  I will have to check that area out because it just so happens it is near an old switch track I recently put down.

Is it possible to get another transformer just for switches and controllers?  If so I guess they have to be "in phase"?  I will have to read up on this since I dont want to put the bulbs back at this point until I have a solution.

Thanks

M

 

[proactive]

How about I disconnect all lamps and see if the problem corrects itself?  Then we will know if its the switches.  If not then I will check the track.

Thanks

M

 

[proactive]

 

Man that sounds cool.  Yes I have lamps in all switches and a wire going from all switches to the fixed voltage pins.

Would you be so kind as to discribe what I need to do as if I were a child?  Lionel Electricity has always been my down fault.

Thanks

M

 

[proactive]

Hi, 

Running Command Control engines, two at a time, Gar Graves track and Lionel O22 switches.  My accessories are connected to other transformers, however the RCS tracks are connected to the O22 as well as the fixed voltage for all switches.

Thanks

[chuck]

If the problems started up with the addition of a few more feet of track, I'd suggest starting to look at those pieces of track.  You might have corrosion on the inside of the track causing increased resistance and voltage drops.  You said you had multiple feeds.  How many?  I would run a seperate drop for every 10-12 feet of track which translates to one drop every three to four sections of Gragraves flex.  Also, what gauge wire are you using and how are the feeds attached to the track?

[MartyE]

I agree with Chuck that the switches will draw but my fathers setup had about 12 switches running a 671 and F3 set.  The transformer got warm but never hot.

[chuck]

Are the switches running off of track power or are you using auxiliary power to a fixed voltage plug.  Each of the lamps in an O-22 consumes 2-3 watts, aka about 6-9 watts pers switch times 13 switches is 80-100 watts of power.  That means about 1/2 of the ZW's output is being used to light lamps.  You can get LED replacements for the lamps or use the constant voltage plugs and an auxiliary transformer for the switches and leave the ZW to power trains.

 As a ZW heats up, the resistance in the rollers goes up and that causes additional heating which leads to higher resistance and so on.

[spankybird]

Have you checked if the wires are tight on the back of the ZW. Are the nuts tight. Also check to see if the wires are connected tightly on the inside of the case.

[ChiefEagles]

Chuck, you could be right.  Something is not right.  I have run as many as 8 diesels in TMCC command on one side of one of my PW ZW's on the same track section.

[chuck]

Are the switches classic O-22's  If so, the lantern lights and switch controller lights are eating a significant amount of power.  A classic ZW is only capable of supplying 180 watts of continuous power, the 250 watt figure originally stated by Lionel is how much power the unit consumes, not how much is available at the output terminals.

[MartyE]

What trains are you running?  The switches and layout size does not sound all that over whelming for a ZW.  Anything else connected to it?  And of course any transformers you have should be in phase.

[proactive]

 

I have a Post War ZW, KW and RW for my layout.  The ZW controls the track.  The track contains 13 Switches and about 256 feet of Gar Graves track.  The transformer is connected at various points in the track.  My KR and RW run the accessories.  I notice that after just a short amount of time, the ZW gets really hot to the touch.   The other transformers do not.  Also, I have noticed the track power has become a bit weaker due to a recent addition of track.

Is there anything wrong with my ZW?  Am I demanding too much from this one ZW?   If so, should I purchase another and put them in phase?  I read a little about in phase and know little about it.  Any help would be appreciated.

 

Thanks

M