How about a listing of all the popular transformers and their output voltage or waveforms?

There are a lot of transformers on the market today. If you include the old Lionel transformers it could be as high as 55 to 70 transformers, maybe more.

Atlas, American Flyer, K-Line, Ives, MRC, Lionel, MTH, Troller and Williams have put out transformers, at least these are the companies I know of that have put out transformers. So a list of all the transformers made would be very extensive. There could be other companies that made transformers that I am not aware of.

Lee Fritz

I think the list of QSI and early MTH engines that don't play nice with the so called "chopped" waveform might be easier, and more helpful than a list of the transformers.  

That said, all the post war transformers would be pure sine wave.  Anything with a power brick and a separate controller will be a chopped wave to some extent or other.  The Z4K is a special case, in that it outputs a more or less sine wave, though from what I've seen the output is pretty distorted... still the engines see it as a proper waveform.  

JGL

What is the Z 750 and the Z 1000? I know the Z4K is special and wondered if the other Zs were shark tooth.

The bricks are pure sine wave, but I think when the Z controller is added it then becomes chopped, Z-500, 750, & 1000.

The Z-controller chops the wave.  

Here's a thread showing the output waveform of a Z-controller and a CW-80 from a couple months back. https://ogrforum.com/t...-and-cw-80-waveforms

JGL

It's mostly the early PS-1 engines that do not like the chopped wave. The later PS-1 engines  seem to run fine on chopped wave once they boot up.

Sure Chuck, you start the list with all of yours.

Ok,

PW ZW, 20 VAC pure sine

ZW-C, 18 VAC shark tooth

CW 80, 18 VAC shark tooth

...y'alls turn next

Sorry bud, we need waveform pictures!

There's a guy out there with the initials M R that could probably hammer this out in five minutes!

PLCProf posted:

cjack posted:

In a thread it was said that MTH engines only should run with pure sine wave waveforms.

I find no such statement on the MTH site or their literature. There is a discussion of issues with early PS-1, but apparently an engineering change was made about 20 years ago to permit proper operation with the "shark fin." See attachment. The attachment further comments that the TIU itself employs phase control which generates the "chopped wave" under discussion. It states that even the TIU caused trouble with early PS-1!

There is a statement that phase control supplies should not be used to power a TIU, only the output of a brick, See second attachment.

Let's get the facts first. Who has the MTH documentation stating that their engines require "pure sine waveforms?"

I do not believe that anyone would have information on the pure sine wave requirement.  cjack is seeking to educate me about this. I made an erroneous statement to a new guy trying to explain that he should use the Z-750 in his case. ( different issue than PS-1) I did not know about the engineering correction to late PS-1 loco's and newer MTH products.

I based that on the recommend transformer list in a TIU users guide that I downloaded from the MTH site. It still leaves out the CW-80.

So, thank you cjack and PLCProf for the knowledge.

gunrunnerjohn posted:

Sorry bud, we need waveform pictures!

lol

A comprehensive list of transformers which lists output wave forms would be very helpful. Locomotive performance issues with different wave forms is not just a consideration with certain MTH locomotives. For example, many Pullmor motored engines with E-units behave horribly with a sharks tooth wave. They grind, rattle and vibrate loudly. I have installed a toggle switch on my layout where I can instantly switch between a Legacy Powermaster with shark's tooth output, over to a conventional postwar ZW. If I flip the toggle over to a sine wave output while a Pullmor locomotive is running along, it instantly quiets down, and runs more smoothly at the exact same speed of operation. It's like night and day. Conversely, some people might want a sharks tooth wave form to boost smoke output. It is really  an engine by engine decision for best performance.

Tony_V posted:

gunrunnerjohn posted:

Sorry bud, we need waveform pictures!

lol

I'm working on it

PLCProf posted:

cjack posted:

In a thread it was said that MTH engines only should run with pure sine wave waveforms.

I find no such statement on the MTH site or their literature. There is a discussion of issues with early PS-1, but apparently an engineering change was made about 20 years ago to permit proper operation with the "shark fin." See attachment. The attachment further comments that the TIU itself employs phase control which generates the "chopped wave" under discussion. It states that even the TIU caused trouble with early PS-1!

There is a statement that phase control supplies should not be used to power a TIU, only the output of a brick, See second attachment.

Let's get the facts first. Who has the MTH documentation stating that their engines require "pure sine waveforms?"

I can personally attest to the fact that the TIU variable voltage will drive some PS/1 and/or QSI locomotives nuts.  I had to stop testing them with the TIU in circuit and just dig out my Z-4000 for those tests.

GregR posted:

A comprehensive list of transformers which lists output wave forms would be very helpful. Locomotive performance issues with different wave forms is not just a consideration with certain MTH locomotives. For example, many Pullmor motored engines with E-units behave horribly with a sharks tooth wave. They grind, rattle and vibrate loudly. I have installed a toggle switch on my layout where I can instantly switch between a Legacy Powermaster with shark's tooth output, over to a conventional postwar ZW. If I flip the toggle over to a sine wave output while a Pullmor locomotive is running along, it instantly quiets down, and runs more smoothly at the exact same speed of operation. It's like night and day. Conversely, some people might want a sharks tooth wave form to boost smoke output. It is really  an engine by engine decision for best performance.

This reminds me of Mike R's video about the smoke output and shark tooth transformers. I don't think I remember him being clear on the details. It seemed to say that the shark's tooth was advantageous regardless of how you were using the transformer and even when I thought about half throttle and the shark tooth peak, I wondered how the power supply in the smoke area was designed to make a difference.

Not enough tech info from these manufacturers especially considering all the incredible capability of the members of this forum. There is no doubt in my mind that this forum is fueling a decent percentage of the O gauge market. Their bottom lines depend on a broader base like the sets, and traditional sized product, but the activity here helps to keep the hobby alive and interesting...and relevant technologically.

Here's my contribution to the waveform library.

Z-1000 with Z-Controller and CW-80 Waveforms

Also, I did a bunch of Z-4000 waveform pictures.

Z-4000 Waveform Pictures with/without load

I like the sidebands on the CW-80

I was amazed when I put the 'scope on the CW-80, it probably explains why there are so many issues using it with stuff like PS/1.

gunrunnerjohn posted:

I was amazed when I put the 'scope on the CW-80, it probably explains why there are so many issues using it with stuff like PS/1.

Maybe a little gain change is all that's needed. I don't remember seeing that on any of the triac controllers I've seen over the years, and I've seen a lot of them. I wonder how they managed that ? 

I did notice the feedback loop on the A output was a little too tight or not tight enough. The output on most of the CW-80s I have had would oscillate enough to show up on the brightness of incandescent lamps. I was using one for accessories. I had to switch to the B output.

Dale M researched the brick in it and said that it is good for more amps than one would think. I forget what, but I'm thinking at least 8 amps when he tested it. So that might be a good end use for the ones without the G in the date code or otherwise broken ones.

The full output looks clean.

I am not that good with transformer outputs, however I know that a Lionel CW-80 won't work with most MTH PS-2 engines. I can't say about the new MTH PS-3 engines as I have not tried one with a CW-80. I don't own a CW-80 or have access to one any more.

One thing that I have learned is that some of the Weaver engines won't work nicely with the MTH Z-1000, a Weaver C-630 I have prefers the old post war ZW.

Lee Fritz

The CW-80 has always been the bastar_ stepchild when it comes to MTH products. Hence the Z-1000 in my small collection.

Come to think of it, many Lionel folks view the CW-80 as the bastar_ stepchild as well. 

Do any of the scopers have a ZW-C (6-32930) or ZW-L to get waveforms?

I have a C and could get to it until this afternoon. It'll look a lot like the CW without the fuzz...I hope...I hope..

Was working on diagnosing a problem with the horizontal amplifier of my HP 1743A this morning and, since I had it out, thought I'd contribute.  Unsurprisingly, the output on my little bench PW 4150 produces a nice sine wave...

This may be the answer to the funny waveform.

cjack posted:

I have a C and could get to it until this afternoon. It'll look a lot like the CW without the fuzz...I hope...I hope..

I am expecting a waveform like the Legacy Powermaster. It has the built-in circuitry for all four channels to perform the same function. Same for the L.

I hope, I hope.

OK, the ZW-C...

Full Power 10 Ohm LoadHalf Power 10 Ohm Load

Looks about right, a little glitch before the triac fires at full throttle and the backwards sawtooth at half voltage.  Ugly little spike on the half-power graph, maybe a good place for a TVS!

That would explain the spikes.

The B and C outputs were feeding turned off trains, but I used the A output and it was only connected to a resistor. I don't know if the other outputs and the entire layout with common U terminals were complicit in the results.

I also have that Lionel volt/ammeter screwed to the outputs...so there is that too just maybe. 

gunrunnerjohn posted:

This may be the answer to the funny waveform.

Too funny - but not the case.  If you look closely at the bottom, you'll see I've got the chop turned on.  B channel is my function generator outputting a 60 Hz sine wave for comparison.

My 1743A apparently spent most of its life at Raytheon based upon the metal asset tag on the case top which matches the asset number behind the CNR sticker.  Left 'em all on as a part of its history.

It was just too easy a target.

Odd that I didn't get overshoot like that on the ones I tested, maybe I used better resistors?

Here's a ZW-C waveform test, at half and full throttle.  Below is the test setup I used.  There is one 180W brick connected, and no channel jumpers to enable the other channels.  There does appear to be a small inductive kick when the triac switches on and off.

PLCProf

Chuck, did you use a 135 watt or 180 watt brick to get your screen shot? 

The 180 Watt Brick, all 4 installed.

Sorry, it's 2 ohms, I thought I put that in there.  It's four 75W 8 ohm resistors in parallel.  At full throttle I had 7.5 amps at 16 volts, so that's close to the current I'd expect with 2 ohms.  Obviously, my wiring adds a little resistance, not to mention all the connectors.