Adding DCS to a conventional layout

#1. Roughly 22 volts, but it drops under light load to around 20, at least on mine.

#2. I set my variable channels to fixed mode, so they come up with full voltage.  If you want to run them variable, just adjust the voltage or hit the TZV key and they drop to variable magically.  The next power cycle, they're back to fixed.

#3. No, it shouldn't cause any such issue.

Phil,

1.  What's the ACTUAL maximum output voltage available?  22?  24?  25?

22 volts.

2.  When operating the layout under DCS/remote control,  on Variable channels 1 & 2,  should I raise the tranny handles to 'MAX'  before using the remote to increase voltage, starting from 0?

Yes.

3.  If the Z-4000 handle is set to less than MAX,  say 18 VAC,  can /will this cause problems?  Such as spurious whistle activation?

There's no problem, however, the TIU's variable channels expect their input voltage to be 22 volts. Therefor, they will output voltage by passing 1/22 of the input voltage for every volt that is displayed on the remote, as follows:

• If the input voltage is 22 volts and the display shows 18 volts, the actual output voltage is 18/22 * 22 = 18 volts
• If the input voltage is 20 volts and the display shows 18 volts, the actual output voltage is 18/22 * 20 = 16.36 volts
• If the input voltage is 18 volts and the display shows 18 volts, the actual output voltage is 18/22 * 18 = 14.73 volts.

When in variable mode, the variable channel's output display will only be accurate when the channel's input voltage is 22 volts. That's why the variable channels, in variable mode, display voltage more accurately when using a Z4000 that can output 22 volts as opposed to a Lionel brick, or some of the MTH bricks, that can only output 18 volts.

This and a whole lot more is all in “The DCS Companion 3rd Edition!" This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at OGR’s web store!

You will want to keep in mind the maximum voltage of what you're running.  If you're running any TMCC or Legacy locomotives they are specified for a maximum of 19 volts.  So, depending on the locomotive mix, you may want to limit the track voltage for operation.

OOPS....Barry says 22 and John says 19 max.  What's a poor neophyte to do?

Also, what about the voltage control that I believe exists in both the Z-4000 and in the TIU's variable voltage;  viz., chopped sine wave ?  If 'chop' is OK,  what about 'chop-chop'?

I HAVE experienced spurious whistle activation;  and could not make it stop!

phil gresho posted:

OOPS....Barry says 22 and John says 19 max.  What's a poor neophyte to do?

Also, what about the voltage control that I believe exists in both the Z-4000 and in the TIU's variable voltage;  viz., chopped sine wave ?  If 'chop' is OK,  what about 'chop-chop'?

I HAVE experienced spurious whistle activation;  and could not make it stop!

John isn't the one specifying 19 VAC max for the Lionel stuff, that's right from the Lionel user manuals.

The Z-4000 uses a sine wave synthesis circuit to produce a near sine-wave output at all voltages, the TIU or the Z-1000 (and similar) use a simple triac output that produces the chopped sine wave you hear about a lot here.

Without more information about your whistle issue, it's hard to speculate on a cause here.

We have all three command control systems on our layout, DCS, Legacy, and TMCC. I NEVER have any of the Z4000s set higher than 19 volts!  Besides, that's all you need anyway.

Phil, for one thing, you could read the thread more carefully.  Your question is what is the max available.  Barry answered that, GRJ then warned that some locos shouldn't have more than 19 volts applied.

There is no reason to set transformer at max, unless you want to replace bulbs.  I set mine about 17-18 and set the variables to fixed.  Also, if you are going to run conventional locos, the less voltage reduction in the TIU, the better the trains will run, due to wave form alteration.

Phil,

Barry says 22 and John says 19 max.  What's a poor neophyte to do?

First, pay better attention. There's no contradiction in what John and I stated.

Second, the variable channel input needs to be 22 volts for variable channels to operate correctly. You can then set the variable channels to any output you like.

Since I know that you have a copy of my book, I suggest that you read it.

BB:  It is, in part,  your book that prompted my Q's!!  To quote:

 1.        p.132:  "The combination of of a transformer that chops the the sine wave and a second chopping of the sine wave inside the TIU, however, is a bad thing and should be avoided."

2.  If using a modern transformer that chops the sine wave to vary voltage, adjust the transformer's output to its maximum voltage setting.  This will bypass any chopping of the sine wave and also ensure that the TIU channel receives the maximum output from the transformer itself."

Now YOU should re-read the threads!  I detect some inconsistencies in your own replies....

    The Z-4000 that I'm using will read all the way up to 25 volts.  That observation,  plus the assertions that its max is 22 volts,  plus the sometimes-strange whistle blows, is the genesis of this thread.

            I plan to do more experiments on more engines to get better data....

phil gresho posted:

 

            I plan to do more experiments on more engines to get better data....

OK but, sure seems like you are "over thinking" this whole thing. Why bother? Just "hook the darned stuff up" , set the Z4000 transformer to 19V output (they might show as high as 22 to 25 with NO LOAD), and run trains! We've been doing it that way for years now, i.e. turn on the master power, set both Z4000 transformers to 19V, and run trains.

Phil,

 1.        p.132:  "The combination of of a transformer that chops the the sine wave and a second chopping of the sine wave inside the TIU, however, is a bad thing and should be avoided."

2.  If using a modern transformer that chops the sine wave to vary voltage, adjust the transformer's output to its maximum voltage setting.  This will bypass any chopping of the sine wave and also ensure that the TIU channel receives the maximum output from the transformer itself."

Now YOU should re-read the threads!  I detect some inconsistencies in your own replies....

Really??

The above statements, which you found in my book, are exactly correct and not in the least inconsistent with what I wrote on this thread. If you believe that there are inconsistencies in my statements, show them to me.

I set my Z4000 to 18 or 19 volts, it always works great.  I suggest buying the DCS Companion Third Edition...money well spent!

phil gresho posted:

BB:  It is, in part,  your book that prompted my Q's!!  To quote:

 1.        p.132:  "The combination of of a transformer that chops the the sine wave and a second chopping of the sine wave inside the TIU, however, is a bad thing and should be avoided."

 

I think this refers (at least in one example) to trying to hook a Z-1000 with its control box to the TIU inputs. If using such a transformer for TIU power (which I did prior to getting a Z4000), hook it directly to the TIU and leave out the control box.

I run my Z4000 at 16v during DCS/TMCC operation with no spurious whistle operation beyond an occasional double signal (but that's due to having a second power feed on the opposite end of the loop without an insulating pin in the center rail)  

---PCJ

Barry:  I'm surprised that you didn't notice your own inconsistency....You just said

"There is no reason to set transformer at max, unless you want to replace bulbs."

Compare this to the 2nd of my 2 quotes from your book.

Phil, BB didn't say that, I did.  I run my TIU inputs at 17-18 volts, and have no problems

Robert,

Phil appears to be having comprehension issues.  

Yes,indeed.  The confusing 'addresses' is slightly incomprehensible....to me!  You'd never believe that I have 3 degrees in engineering! [BSChe,  MSNucEng, PhDChE....]

There appears to be some unnecessary confusion here.

1) Z4000 does not chop the sine wave.

2) The 19 volt limit for Lionel refers to track voltage; not transformer voltage. So, go ahead and set the Z4000 at full voltage and then via the TIU keep the track voltage below 19 volts.

Phil, precisely what is slightly incomprehensible?  Each TIU on a layout, up to 5, should have a unique address.  Addresses can be any number between 1 & 5, inclusive.  The address is set via the remote, under System and TIU setup.  The address of a particular TIU can be determined by counting the number of flashes by the internal LED, in the lower left corner when viewed from the top from the input side.  A new TIU comes set as TIU#1.

Barry, I know I'm perfect, but if someone can't comprehend what I have written, it must be because I haven't written it as clearly as I could/should have.  I must have been relying on my innate perfection to comprehend what I authored without realizing that in the absence of such knowledge my golden words may not be so clear to others.

Oman, the only reason for setting transformer output to full voltage would be so the voltage reading on the remote is accurate.  But what difference does it make whether it is or isn't?  If running conventional, one adjusts the voltage via the thumbwheel to get the desired speed.  The downside is that the greater the voltage drop being established by the TIU, the harder it is to run a conventional loco very slowly, due to waveform alteration.

Also, running at reduced transformer voltage creates a means to guard against accidental overvoltage on the tracks.  Certainly, one can run their RR any way they want, but I find that, with good wiring (I use 14-gauge), 17 volts is adequate & 14 is not quite.

So here's where I stand @ this moment:

1. Keith asserts the the Z 4000 does not chop the wave.  How then DOES it vary voltage?  [Is it not what Barry refers to on p. 132 Rev 3, as a "modern transformer"?]

2.  I confused RJR with my use of "addresses"....  I was referring to the way this forum associates a member's 'address'/name/monicker/etc,  with the  content of the message.  I'll be more careful in the future.

3.  I agree that setting the Z 4000 handle so that the remote reads the 'exact' voltage is of minor importance.  What I care more about is the possibility of problems related to multiple wave choppings.  I guess I'll use 'full' tranny output from now on.

The Z4000 is a electronic power supply, much like a UPS. However, a UPS puts out a fixed voltage, typically 120 VAC. The Z4000, can vary it's output from 0 to 22 VAC. It's, not a perfect sine wave, but certainly good enough to run our trains. MTH did this to achieve a UL listing for toy transformers.

Phil, trust me.  The Z4000 does not have to be on full.

phil gresho posted:

1. Keith asserts the the Z 4000 does not chop the wave.  How then DOES it vary voltage?  [Is it not what Barry refers to on p. 132 Rev 3, as a "modern transformer"?

As an aside, I may be the only one but I think your questions are quite reasonable in the context of a new command control user trying to get a grip on the semantic gymnastics of AC power supplies.

I'd have to disagree that the Z4000 uses the classic chopped waveform, it really doesn't.  It would be very difficult to "filter" a classic chopped waveform to create the Z4000 output waveform, especially at higher currents.  The Lionel ZW-L uses the classic chopped waveform, here's a comparison.

Looks like Stan is talking about the Z500/750/1000 family and GRJ about the Z4000.

Sounds like he was talking about the Z4000 to me.

Many power supplies (including the Z4000) add circuitry to mask (or "filter" to use a technical term) the chopping so what appears at the output looks more like an ideal wave which in this case would be sinusoidal in shape.

If you're going command-only operation, then the bricks will be all you need. The Lionel 180-watt bricks give you the most power in this case. If you also want to run conventional, then you want to use a Z4000 or the MRC "Pure Power Dual" as your source because they have a a clean sine wave output.

We can agree to disagree.  For example, look up the definition of a chopper circuit in the context of electronics such as from Wikipedia:

https://en.wikipedia.org/wiki/Chopper_(electronics)

The Z4000 is a switching power supply that re-shapes the incoming 120V AC signal using chopping techniques.  As it turns out the chopping is going on at many kHz rather than at 60 Hz.  This is what I mean by ad hoc terminology confusing the issue.  It is true that 60 Hz is the most common choice in cheap supplies since there are inexpensive components to do so.  But in a "modern" or "electronic" supply (more ad hoc terms that have been tossed out) with inexpensive digital components and switching devices (FETs,) it is trivial to "chop" a 60 Hz waveform 10s, 100s, or 1000s of times per cycle to reduce the RMS of the voltage.  I think it's almost laziness (or probably the tiny market for O-gauge AC supplies) that stops manufacturers from doing so.  At a high enough chopping rate, a passive filter with sufficient current carrying capacity to smooth out the chopping would be inexpensive.

So, yes, the Z4000 is not a "classic" chopped waveform (but it does synthesize the variable voltage by chopping).  But now you've introduced yet another ad hoc term of a "classic" waveform to add to "modern" and "electronic". 

OK, on that we can agree.  The waveform is digitally generated, so in that sense, it's a "chopped" waveform.  I read the first one as suggesting you could filter the 60hz waveform to create the sine wave, that would be pretty tricky.

For the life of me, I can NOT understand this continuing "discussion" concerning what voltage to send/apply to the various track circuits/blocks. The Lionel 180 "bricks" put out 18/19 volts. Thus I set both MTH Z4000 transformers to 19 Volts. We use ONLY command, i.e. DCS, Legacy, and TMCC and the whole ****ed layout operates great! Just why all the technical questions?   Sort of like the Bumble Bee, i.e. from a technical/aeronautical standpoint, its wings are too small. However,,,,,,,,,the Bee STILL FLIES! 

stan2004 posted:

phil gresho posted:

1. Keith asserts the the Z 4000 does not chop the wave.  How then DOES it vary voltage?  [Is it not what Barry refers to on p. 132 Rev 3, as a "modern transformer"?

The Z4000 varies the voltage by chopping the wave.  A source of confusion in this discussion is the ad hoc use of terms such as "electronic" or "modern" in reference to a power supply.  To your point, a "neophyte" has absolutely no way to know that there are many ways to chop a wave for the purpose of reducing, varying, or re-shaping a voltage.  Even the "electronic" UPS with its fixed output voltage chops the wave internally to create the output voltage.  That is, chopping is commonly employed in both fixed-output or variable-output supplies.

 

Many power supplies (including the Z4000) add circuitry to mask (or "filter" to use a technical term) the chopping so what appears at the output looks more like an ideal wave which in this case would be sinusoidal in shape.

 

Also, statements have been made that setting a so-called chopped controller to "full" or "max" disables the chopping.  Well, without getting into the nuts-and-volts of circuit design, let's just say this is a your-mileage-may-vary claim.  For example, here's an MTH Z-power supply which has 2-parts, an AC transformer black brick and a Z-controller throttle.  The AC transformer brick indeed puts out a nice sinusoidal output.  The Z-controller "chops" the sinewave based on the throttle setting.  But if you set the throttle to "FULL OUTPUT" does it simply pass thru the incoming brick output?  Decide for yourself.

 

 

As to how a variable-output TIU channel would deal with this "FULL OUTPUT" waveform from a Z-controller is a curious question.  Could this cause spurious whistles?  Who knows! 

 

If given a choice, I'd apply the brick output directly to the TIU variable-voltage input and bypass the Z-controller.  Obviously if you have a "chopped" supply that integrates the brick and controller you do not have this option.  Again, it depends on how it is designed but, for example, it doesn't take much imagination to envision a power supply that detects the throttle at max "full power" position and then just shunts the input directly to the output in a bypass-like mode.

 

As an aside, I may be the only one but I think your questions are quite reasonable in the context of a new command control user trying to get a grip on the semantic gymnastics of AC power supplies.

 

 

Stan

You seem to have gone off in the weeds. I have read many of your replies or posts and you appear to be very knowledgeable in electronics. You must know what a switching power supply is and you probably know what a class D amplifier is. Basically the Z4000 functions like a crude class D amplifier.

We all have class D amplifiers in our lives, but we don't refer to them as chopped AC or chopped sign waves. They attempt and do replicate the original (audio) signal source very well. The Z4000 does the same. but do not call it chopped. A triac or SCR can be employed to chop the sign wave.

AGHRMatt's comment raises a question in my mind:  is the PH180 a pure sine wave output?  Since there is no way to control its output voltage, I can see no reason why it wouldn't be.  If pure sine wave, it would be fine for feeding a variable TIU channel for conventional operation.

Robert,

The only issue that I can see regarding using a PH180 to drive a variable channel for conventional operation is that the remote's voltage display will read higher than the actual channel output.

IN all other respects, it should be fine.

I agree, Barry, and is meaningless when operating for resons I've stated elsewhere.  But Matt's statement implies the PH180 is not suitable for conventional because it doesn't have a clean sine wave.  I don't have a scope to check this out, but both John & Stan do, so I was trying to pick their minds.  For reasons having nothing to do with performance, I replaced a PW ZW with a single PH180, feeding 2 variable-set-to-fixed channels, and I find it to be perfect.  Only complaint(?) is that the breaker is too quick.

Oman posted:

Stan

You seem to have gone off in the weeds. I have read many of your replies or posts and you appear to be very knowledgeable in electronics. You must know what a switching power supply is and you probably know what a class D amplifier is. Basically the Z4000 functions like a crude class D amplifier.

We all have class D amplifiers in our lives, but we don't refer to them as chopped AC or chopped sign waves. They attempt and do replicate the original (audio) signal source very well. The Z4000 does the same. but do not call it chopped. A triac or SCR can be employed to chop the sign wave.

Well, Wikipedia (in the link I supplied above) defines a Class-D amplifier as a type of chopped amplifier.  That's why I am comfortable calling it chopped.

I've learned not to mind being in the weeds as I can't hit the ball straight down the fairway to save my life but I digress.  If you fed a class-D amplifier output into the fixed input of a TIU it would be a sight to behold!  A typical class-D amplifier as used for audio depends on the speakers' (and human ears') inability to respond to the rapid chopping of the waveform.  If viewed on an oscilloscope as shown earlier a class-D amplifier from a typical consumer audio device would be chop-suey heaven if there is such a place!   I simply can't imagine how a TIU variable channel would behave if given a generic class-D 60 Hz power signal.  Or, for anyone who has an oscilloscope and too much time on their hands, take a look at the speaker signal in a PS2 or PS3 engine.  The amplifier is a class-D chopped amplifier.  The waveform is chop-suey heaven!

Again, I believe it is the small market size in O-gauge that we still have what GRJ says are "classic" chopped supplies; he may have coined a phrase here!  When I see posts in this thread using terminology such as "modern" and "electronic" power supplies I think of what the rest of the world (outside of the O-gauge community?) thinks.  This is the context by which I see the OP's original question as a self-proclaimed neophyte to the power supply world.   For example, "classic" lamp dimmers utilized the "classic" chopping technology you refer to (I didn't want to bring up the "triac" but I see you did!).  These had horrible problems with buzzing, flickering, etc. and were long-ago replaced with "modern" lamp dimmers that also use chopping but with methods more akin to the Z4000.

So, not that it matters but, I say the Z4000 is indeed a chopped amplifier design of a "modern" ilk.  So we can agree to disagree.

WOW!!

And,with due apologies to HOTWATER, I'll add a bit more 'fuel';  summarizing why I started this post, and ending with a lot more Z4000 confusion:

1.  The small HO club I belong to decided to let me upgrade their small 3-rail layout from a Z4000 wired directly to the track  [i.e., conventional control only] to simple command control via a TIU and a DCS remote.  I added a TIU and wired the two Z4000 outputs to the two TIU Variable channel's inputs;  then from the 2 TIU outputs to 2 centrally-placed terminal boards and from there to the several track sections/blocks.  There are 2 independent loops of track;  no turnouts connect them.  Baby simple.

2.  Following Barry's book,  I set the Z4000 handles to 'wide-open'.  Then,  when controlling speed via the thumb wheel, some engines ran with the whistle ALWAYS ON....once the indicated voltage on the remote reached 14 or so.

3.  If the Z4000 voltage was reduced to ~ 16 volts or less, the whistle-blowing stopped.

4. Now for the 'kicker':  While operating both loops via the remote,  I discovered that when the Z4000's output, on either handle, reached ~ 18 or 19 volts, with the other fixed at 14 -16 volts,the whistles on BOTH locos turned on!  Reducing the voltage stopped the noise.

I suspect, but have no way to prove, that the Z4000 itself is the culprit.....Somehow there seems to be some internal, and spurious,  'cross-talk'.

          OK guys [excluding HOT WATER, of course];   your turn!

RJR posted:

I agree, Barry, and is meaningless when operating for reasons I've stated elsewhere.  But Matt's statement implies the PH180 is not suitable for conventional because it doesn't have a clean sine wave.  I don't have a scope to check this out, but both John & Stan do, so I was trying to pick their minds.  For reasons having nothing to do with performance, I replaced a PW ZW with a single PH180, feeding 2 variable-set-to-fixed channels, and I find it to be perfect.  Only complaint(?) is that the breaker is too quick.

I didn't say that. It's not suitable for conventional operation because it's just a step-down transformer -- 110VAC in/18VAC out in pure sine wave with a fast blow circuit breaker -- no voltage control. You can put it on a TIU variable channel, but your maximum voltage will be 18 volts as opposed to 22v, so the track "voltage" reading on the remote will be off -- i.e., 6 volts is actually 6/22*18 volts or about 4.9 volts.

We have a couple of Lionel Bricks on the club layout, but for conventional, the track outputs on the Z4000's are connected to Fixed 1 and Fixed 2 on the TIU's to support conventional locomotives on those occasions when we run them.

RJR posted:

AGHRMatt's comment raises a question in my mind:  is the PH180 a pure sine wave output?  Since there is no way to control its output voltage, I can see no reason why it wouldn't be.  If pure sine wave, it would be fine for feeding a variable TIU channel for conventional operation.

Pure as the driven snow.   The PH180 waveform comes right from the transformer, no electronics get in the way.