CW-80 and legacy electronics

I'm not sure if a CW 80 will hurt the electronics, but its certainly an odd duck. I had one that I used for accessories. I later upgraded to a 180w brick for my accessories and they ran better at lower voltages to boot.

The 180w brick is a far superior way to power CC locomotives and it has one of the fastest breakers in the hobby to protect your trains.

I do not trust CW80's with modern electronics. They are fine if you are running conventional locomotives with a basic electronic reverse unit. I have blown electronic boards in the LionChief locos running in conventional mode.. The small power transistors can not handle the heavly chopped sine wave at lower voltages. And postwar locomotives don't like them for the same reason, the motors growl and overheat with these transformers. Bad design. And they commonly go bad. Get the improved version.

You have to ask yourself: Do You Feel Lucky?

Here's the waveform from the CW-80 at full throttle.  Doesn't look like anything I want to feed my trains.

CW-80 at Half throttle.  Hmm, looks worse!

I tried very hard to like the CW-80, but at the end of the day it is not a good transformer. While I have no direct experience with damage to electronics, I have personally seen a bunch of goofy failures that make the thing difficult or impossible to use. Never tried to use it with Legacy or TMCC, but I would be I would not be surprised if there are problems.

Personally, I would use the 180 watt brick with the Legacy Powermaster if you want the ability to do conventional.

Probably one of the worst transformers ever made in the modern era. I have one on my bench that I use for test power but that's it.

As GRJ's images show, this is a better looking wave.

Spend the extra now on the brick. Better than the cost to repair an engine.

@PLCProf posted:

I tried very hard to like the CW-80, but at the end of the day it is not a good transformer. While I have no direct experience with damage to electronics, I have personally seen a bunch of goofy failures that make the thing difficult or impossible to use. Never tried to use it with Legacy or TMCC, but I would be I would not be surprised if there are problems.

Personally, I would use the 180 watt brick with the Legacy Powermaster if you want the ability to do conventional.

That's still a chopped waveform, but a clean one, so better?

I used to use CW80s for accessories, but they oscillated a bit on the accessory output. Annoying when it's a bulb intensity varying.

I too have tried to like the CW-80 but even in my limited usage I see strange things occur that are cured when I bring the old ZW out. That leads me to two questions:

1) Is the GW-180 the same DNA as the CW-80?

2) I have never understood how the "brick" works or is connected... Growing up with transformers I keep looking for a lever to turn. Can anyone explain in layman's terms?? Thanks!

The RS-1 transformer from the late 80's is a close contender of the CW80 for worst transformer. They weren't on the market very long and long forgotten about today.

I would guess that the GW180 controller is somewhat different since the transformer for it is higher power.

The 180 watt brick is just a fixed transformer of 120vac input to 18vac output...with a superior electronic circuit breaker on the output.

I've never looked at the output waveform of the GW-180, but I'm guessing it used similar electronics.  One can only hope that they tried to fix the awful ringing waveform of the CW-80 in the design.  If the GW-180 ever crosses my bench, I'll slap a 'scope on it and capture the waveform.

In contrast, the Z-1000 controller has the chopped waveform, but not all the ringing on the waveform.

Z-1000 Half-Throttle Output Waveform

Z-1000 Full Throttle Output Waveform

When I first upgraded to Legacy, my CW80 worked perfectly, powering my single Legacy loco and Legacy Powermaster. Once I got a second Legacy loco, I upgraded to a 180W brick.

@cjack posted:

I would guess that the GW180 controller is somewhat different since the transformer for it is higher power.

The 180 watt brick is just a fixed transformer of 120vac input to 18vac output...with a superior electronic circuit breaker on the output.

Chuck, you may be assuming facts not in evidence.  Just because the CW-80 and GW-180 have a different input transformer power, that doesn't mean they didn't use similar circuitry to control the power.  That being said, I would be somewhat surprised if the waveform is as ugly as the CW-80.

It looks like there isn't any phase shift on the trigger signal which results in less than full output...on the Z1000.

@gunrunnerjohn posted:

Chuck, you may be assuming facts not in evidence.  Just because the CW-80 and GW-180 have a different input transformer power, that doesn't mean they didn't use similar circuitry to control the power.  That being said, I would be somewhat surprised if the waveform is as ugly as the CW-80.

One can only hope!

@gunrunnerjohn posted:

You have to ask yourself: Do You Feel Lucky?

Here's the waveform from the CW-80 at full throttle.  Doesn't look like anything I want to feed my trains.

CW-80 at Half throttle.  Hmm, looks worse!

GRJ - wow this is fascinating! I'm assuming there's a triac involved at someplace in the electronics for that spike to occur? It's amazing that one can clearly pick out the characteristic curves for the charging/discharging of a capacitor as the wavefrom nears 0V on both the positive and negative portions of the cycle.

Do you by chance have the output of the Lionel PH180?

I might have to add an oscilloscope to my wish list - used them practically everyday during college.

Just look up sine wave on Google for a look at what comes out of the PH180, it's a pure sine wave.

@cjack posted:

That's still a chopped waveform, but a clean one, so better?

Yes, the Powermaster output is almost perfect for a chopped waveform.

My 'scope decided not to print to USB anymore, so I had to snap photos. Sorry about that.

This is my track voltage measured on the track with light load (just bumper lights and a couple illuminated cabooses. Does not change with load.

Some years ago I posted the results of detailed testing of the overload protection in the Legacy Powermaster, not only does it have overcurrent trip, it also has current limiting, so no matter how solid the short, the current can't exceed a certain value. I think the limit was 25A for 3 cycles and 10A after that but I'll need to chase down the old post. Because of this, when using the Powermaster it is rare to trip the breaker in the 180W brick; the Powermaster works first.

I haven't looked at the new PowerMaster, but those are pretty good looking waveforms, about as good as it gets without sine wave synthesis like the Z-4000.