Problem with Lionel CW-80 multi-transformer setup

[philo426]

Good thing you discovered the problem and could quickly correct it!

[KerryS]

Wow.  Thank you all for being willing to help!  I'm embarrassed to say that it turned out to be a careless error.  I really couldn't explain why it wouldn't work, even with the idiosyncrasies of the CW-80, when all I did was add a separate power source to a common ground.  I decided to go back to just the CW-80 to confirm that _that_ still worked.  And guess what, it didn't, so then I knew it wasn't the 2nd transformer, it was something else that I had inadvertantly screwed up.  And here's what it was: I originally disconnected the three wires from the CW-80 so that I could phase it with the Type W.  All well and good, except that when I reconnected the track to the CW-80, I reversed the wires.  Put them back the way they should have been, and now all is right in the layout world!  Thanks again!

[lionelsoni]

8ntruck is on the right track, except for calling the CW80's technique "chopping".  It's "phase-fired control"--"chopping" is something else.  Wikipedia has a good article on PFC.

The CW80 has another little trick:  It shifts the firing times of the two pass elements (triacs) slightly, one earlier, the other later, to put a small DC component into the output voltage, in order to blow the whistle or ring the bell.

I think I know where Rob is going about the date code.

[ADCX Rob]

KerryS

Any ideas on why this isn't working as expected?

Need more info. What is the date code on the bottom / base of the CW?

Explain your "phasing" process.

[8ntruck]

Welcome to the forum.

I'll explain that I am a retired mechanical engineer, that knows enough about electrics to be dangerous.  With that caution, I'll offer an opinion on what may be going on, and hopefully, somebody with better knowledge will came along with better advice.

What I think is going on is a mix between old and new technologies.  The prewar type W is a true transformer that changes voltage by picking up the output voltage at different points on the secondary winding.  If you look at the waveform of this transformer, it will have the same AC waveform regardless of the voltage selected.

The CW80 is one of those new fangled electronic widgets that 'chops' the AC wave to vary the voltage.  I understand this principle, but have no idea how it works.  The resulting waveform is kind of like a saw tooth instead of a sine wave.

When you mix those two 'types' of power, strange things happen.  I learned this the hard way when I tried to run my early Legacy unit with a CW80.  They didn't play well together and the locomotive did weird things, kind of like yours.  Just for the grins of it, I tried using a 1033 for power, things worked as they should.  Yes, I borrowed an oscilloscope and took a look at the 'power signal'.

I'd try replacing the type W with another CW80, or replacing the CW80 with a post-war transformer.  I have a portable Polar Express themed layout that I have powered with a pair of CW80s, and they seem to work fine.

Good luck and have fun.

Please, remember my disclaimer.  This is an opinion, not expert advice.

[pennytrains]

aboard!

[KerryS]

I have an O-gauge layout that was powered by a single CW-80 (A and U to track, B to No. 022 turnout fixed voltage plugs and to lighted accessories).  All was working fine.  I wanted to offload the accessories to a 2nd transformer, so I phased the CW-80 with an old Lionel Type W transformer, moved the accessory power feed to the new transformer, and tied the U terminals of the two transformers together (see picture).  However, now I'm getting weird behavior.  If I start the train via the CW-80, then power up the accessories with the Type W, all is working.  But if I hit the "direction" button on the CW-80, the accessories go out, the train stops (in neutral - still powered), and will not restart with the "direction" button. It will stay like this indefinitely (power to the accessories does not come back on its own, and hitting the "direction" button again does not restore power to the accessories or restart the train).  The only way to get things going again is to power down both transformers, then bring them up again in the same sequence (CW-80 first, then Type W).  Same thing happens if I power up the Type W first, then try to start the train.  This is not the behavior I expected or wanted.  Prior to adding the 2nd transformer, I could stop or reverse the train, and the accessories would stay powered throughout.  Any ideas on why this isn't working as expected?