New ZW-L Inaccurate??

Probably "Inaccurate (but consistent) meter readings?"

Well, being electronic control, the cal pots could adjust the actual voltage in relation to the handles.  I'm not saying it has them, only that it's possible.

Just out of curiosity, I connected my Fluke True RMS meter to the MRC PurePower 270 here.  Since this is a straight transformer, there's also no question about triacs and distorted sine waves.  The voltmeters are dead on, but the ammeters read about 10% low throughout the range.  I guess that's as good as it gets for cheap meters.

>>>Where I have myZW-L mounted the benchtop completely blocks the view of the meters unless I bend down to look directly under it.  The meters on both the MTh and Lionel units work for me mainly as a diagnosis of short circuits, etc.<<

LOL, simply amazing.

Joe 

Hi Folks,

Several things were compromises to deliver the ZW-L.  The Iconic ZW, was the inspiration for this product.  The ZW had markings on the handles up to 20, roughly representing the voltage to the track.  The same for the ZW-L; and remember we could only deliver 18VAC RMS under typical load, so we compromised.  Kept the Iconic look, delivered the best in class power to the track.

The ZW-L will deliver slightly above 18VAC no load, and slightly below 18VAC under full load, per channel.  The meters are calibrated, and are accurate with +/- 1v.

Of course, if you need to measure track voltage to 0.1v - then running trains may not be for you.

Thanks Jon.  Very much appreciate you taking the time to chime in here.  Always important to keep things in perspective, and running trains with the best possible performance is what it's all about when all is said and done.  Sounds like Lionel has a winner here. 

David

One of the very best responses I've ever seen on OGR!

Jon, Thanks for responding.  And no I don't need to run within 0.1v, haha.  But I do want to look at the meter, set the voltage and be within that 1 volt buffer.  So it sounds like that will be the case.

Thanks

Originally posted by RockyMountaineer:

Thanks Jon.  Very much appreciate you taking the time to chime in here.  Always important to keep things in perspective, and running trains with the best possible performance is what it's all about when all is said and done.  Sounds like Lionel has a winner here. 

Well said RockMountaineer!  In the final anyalysis it is all about running our trains with the best possible performance.   Bo

Visit my website Bo's Trains at http://www.bostrains.com

Good to hear that the meters are calibrated to within +-1v.   As I guessed, there was no attempt made to align the handles/dial readings- essentially those are styling points.

Thanks for the response Jon!

Generally, very good analog meters will be within 5% of full scale. Mirrored scales can usually do 2%. Most analog meters are most accurate at half scale.

So that's just how it is.

As to the ZW-L, if it's calibrated to 1 volt, then that is 5%. since Jon said "calibrated" that makes me think there is some potentiometer adjustment inside. Those kind of meters aren't generally that accurate...unless they are calibrated before they are installed when they are coming off the manufacturing line. Whatever.

As to the large discrepancy between what we are saying here, I don't know if even a "400 dollar" supposted RMS Fluke can correctly decipher a half sine wave and display the RMS. I don't know how they do that. Ideally it should measure a number of points, square them, take the mean, and take the square root. Or even better, measure the heating power of the voltage.

So it's not trivial. I would guess that Lionel calibration holds best at 18 vac. Anyway, you can be sure it's repeatable. That would be it's most valuable feature.

Analog meters respond to the average value of the

applied voltage(rectified). The meter will then be

marked to show the RMS value of the applied voltage. 

This only works for a sine wave where the average/RMS value

can be calculated.

The Z4000 output is a sine wave at all output values so any meter

will give a correct reading.

The ZW L puts out a chopped sine wave at low values and  very

close to a sine wave at full voltage.

The RMS voltage is a voltage that gives the same heating effect

as an equal DC voltage. RMS meters use some form of measuring heating effect of the applied signal.

The meters on the ZW L indicate the RMS value of the output. Using the heating effect is a method to measure RMS that is out of date but the results are still the

same.

Guess I will stick with the Z-4000.

I've been following this post since the beginning and don't understand why it makes so much difference what the voltage measures. Reasonably accurate yes but if it's 2 volts off what difference does it make? I'm sure they put in the best meters they could find for the price point they're trying to meet. We're not talking about power supplies for a multi-million dollar main frame running the countries missile defense system.

Ron

Another classic Forum lynch thread. Lots of hostile speculation and griping, then comes a few sentences of rational explanation (thanks to Jon for calming down the mob), and everyone quiets down and slinks home.

Don't need no stinkin' fluke.

First of all I'm not sure why everyone on here seems to assume a question on a new product is hostile.  I think you all need to relax.  It's a question on a new product I did not understand.  I'm a software engineer not electrical.  So thank you to all who replied with positive information.  I still wish the handles and gauges would all match, but the transformer is still great in many ways.  No complaints just questions I had (hence the question marks in the title).  So I think we have had adequate answers and can end this thread.  Jon confirmed the output will be within 1 volt of the meter so that's good.  

AMEN!!!

It's time to get off the computer and run some trains!!

SandJam, I found this to be an interesting, educational, and informative thread.  I think that only one post was hostile, and is not representative of the majority of folks here, who enjoy discussion and some give-and-take.  The points raised were interesting enough that they drew out a comment from the Lionel CTO.  Thats cool.

THIS WAS A VERY INTERESTING AND EDUCATIONAL THREAD.

First, because it brought up a topic that was interesting and ultimately led to a good understanding of the facts. Ken-O-Scale put it well above.

Second, this is a great example of why one has to be careful and just a bit wary of what one learns or hears on the internet and forums.  Whatever one thinks of any person who posted here, or the opinions expressed and experiences discussed and "facts" given, not everything -- not even a lot -- of what was said above was both factual and applicable in the context needed here.  No one lied, but some people were misinformed, or misinterpreted or took out of context what had been said or done. The lesson to me is that a lot of "information" that gets posted by apparently knowledgeable and definitely well-meaning people is, if not wrong, inappropriate or in a context that is not entirely appropriate for my situation -- and therefore not necessarily "correct."  Lesson: be careful, and take everything with a grain of salt.

I'm particularly sensitive to this. Last year, in a long and at sometimes mildly contentious thread about track cleaning, I saw several people swear by a miracle cleaner called Simple Green.  I have accepted the fact that even if I win the Nobel Prize for Model Trains (I'm expected the committee to call at any moment) I will forever be associated on this forum with that debacle and little else. That lesson cost me a lot of embarrassment, not to mention more than three thousand dollars and two months in track replacement.   And actually, what was said on that thread was correct: Simple Green is a spectacular cleaner - for floors.  And it does clean track well, too - it just permanently damages it by removing a lot of the metal, too, while doing so.  

So with those lessons in mind, I have my ZW-L mounted under the workbench where I have to bend nearly double to read the meters, accurate to within a volt or so I now know, but I can if I need to.  I have to bend my head back to read the calibrations on the throttle that go from 1 to 20 that I now know roughly correspond to a somewhat linear range of 0-18 V RMS- but I can see them when and if I need them.  And none of this changes at all the most important "fact"to me: when I push the throttle forward, the train goes.  When I pull it back, the train slows.  As it was at age five, so it is now. Life is pretty good!

LEE: Having said all that , Knowing what you know now, Would you do the Simple Green Postings all over again? (I am not referring to the actual cleaning of the track using simple green). I for one am very thankful for the Simple Green Saga, taught me alot. Thanks.

You think you got grief over your choice of cleaning fluid? 

Jon

Simple Green was a popular cleaner in milking parlors. And there is a product called S100 that is very hard on paint like the semi gloss on vehicles. The big issue for these cleaners is that they have to be rinsed thoroughly thoroughly thoroughly or damage will occur. Better not to use them...preaching to the choir here 

Back in the '70s we used "But officer, I keep my house at 55..."

I agree Sean. I've never understood why someone would want to limit any information exchange even if it dances around the topic.

Yes, I would.  It was/is embarrassing.  But I lived and I will live it down eventually. 

This will sound corny, but I really like this forum and the people on it alot. And I've learned a lot here.  So, given what I had discovered, bad as it reflected on me, how could I not come clean (pun intended) about this?  

For the most part, people have been very good natured about it and a little ribbing and joking is called for and I don't mind it. 

Hey Lee: Great Answer, Almost exactly what I figured you would say, THANKS, Casey.

I am glad we can have a little fun ribbing each other.  This is a fun hobby and I don't mind questions.  Now back to running trains in the lab!

Ah, geez . . . .don't rub it in!  You get paid to do that!

Ron you're right on target.  WTF difference does it make?

Yes, well said Ron (And Nick).  I had refrained from saying anything before, but I'm happy to see that others share my viewpoint. From all that I have read so far, the ZW-L is a superlative controller, and I could hardly believe it when some started complaining about such a trivial matter as the handle markings not exactly matching the meters. Thankfully Jon explained that to the satisfaction of all. 

Different strokes for different folks.  I've come to rely on the digital volt and amp readouts on my z4k and know at a glance if something isn't right.  Two volts is the difference between power to run and sit and hum (i.e. 11v and 9v).  I'm not going to get into my reasoning (dead horse) for reliable readouts, but we all operate differently.  I think the OP asked a logical question, and found this thread to be very useful.  No doubt if I was accoustomed to the readouts on the ZW-L, I'd feel the same way about that unit.

Stack   

As I said earlier I don't like people that post stuff just to make others feel bad.  But since this won't seem to die of natural causes here goes yet again!  2 volts is a huge difference when you are talking about Operating accessories.  That 2 volts is the difference between one running perfect and not.  The Barrel loader is a prime example.  Again I said earlier I have a ton (over 100 operating accessories and they all run on different voltage.  So the guages and markings are important to ME.  Maybe not to you, but they are to me.  Many of you have layout with just track and scenery.  Mine is all about the action.

Since we are on the topic about trivial details.  Little details like that you think are trivial are the difference between superior design/execution and average design. 

As I said I bought 2 and am keeping them both.  Still the best transformer out there no doubt.  I was trying to find out why the discrepency, thats all. 

 How about you?   How many have you bought?

It's a amazing what you guys will pay for a over price transformer whether its the new ZW or the Z4000.

All l I did was purchase a twenty amp 20 volt transformer from Newark, install a cord and fuses, connect it to a TPC 300/400 or TIU and you are done. Hundreds a bucks cheaper.

But like Stack said different strokes for different Folks.  Have fun.

Its true the ZW-L is very expensive for a transformer, but even with your 20 volt transformer you have to buy a TPC which is still about 300-400.00 so thats about the same as a Z4000 no?  Besides, now that the ZW-L is updated with all the levels of electronics protection and the power, it should be a once in a lifetime purchase and be able to run trains for a long time, just like it was for the Postwar ZW for decades.

Besides I love spending money 

For all the pseudo science on why the meters don't match the output, Lionel has only itself to blame. The meter scales are obviously custom made. They could have been much more accurate by having someone take a meter with no scale, moving the handles while reading a calibrated multimeter connected to the outputs, and marking the voltage readings on the blank analog meter scale instead of simply printing a linear scale and installing it the meter. No fancy calibrating correcting electronics needed.

Pete

Hey Jon,

Nice to see you still posting and explaining things to a rough bunch of folks

As far as playing with trains,get to work on new exciteing stuff man!!!

I;m not picking on anyone here but to each there own!

Doug

No offense, but I think you rather rude, judgmental comment deserves it: It's only overpriced it you can't afford it.

You guys all missed my point about 2 volts. ALL meters on transformers can possibly be inaccurate whether a z4000 or zw of any kind with a meter and each transformer of a given model could be different than another one. Even if they're inaccurate they ALL will replicate the voltage time and time again. So if you set it to 14 volts today and it really is 13 volts when you use it tomorrow or next week when you set it to 14 volts it will again be 1 volt off. As a result you can use it to run things at there correct voltage by finding the setting that works the best and replicating it every time thereafter. The ACTUAL voltage reading is somewhat irrelevant.

Ron