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Lionel just posted a very interesting video from Mike Reagan comparing smooth sine wave transformers to chopped wave transformers.  It includes a very nice visual demo of the performance of the smoke and coupler features with the 2 different types on a Legacy locomotive.  I personally learned a lot and I'm glad I went for the TPC 400 - 2 x 180watt brick combination. 

 

http://youtu.be/1Ilj3p-Ov3c

Last edited by Chris Lord
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I agree, this is very interesting and full of good information.  I enjoyed it. Clear why modern units run better on modern power supplies, too.

 

Does anyone know if the Z4000 produces output power the same way?

 

That said, as an EE and power engineer, I have learned to appreciate pure sine wave power.  I kept thinking about the high-frequencies being created and the spectrum of the power flowing into the track.  Obviously Lionel locos are designed to disregard harmonics, etc.  I guess other brands are too as I've never had a problem with Lionel or MTh locos running on either CW-80 or Z4000 power.  

I'm gonna take some flak for this, but this is a fairly misleading demonstration without the use of an oscilloscope.  Throttling back the CW to match the indicated voltage of the 1033 is a virtual "smoke & mirrors" trick to discount the entire field of postwar transformers.

 

The scope would show the voltage of the CW still at 18.8-19 volts while the meter showed Mike's 15+ volts, and the 1033 is at its peak output at 15.5 volts under a light load.  The comparison should have been done with an LW transformer(the closest, output-wise, to the CW of any postwar transformer - 125 watts input - 75 watts/5 amps output) set to 19 volts to match the true voltage of the CW.

 

 

I use two Powerhouse 180 bricks and only run in command mode. I only power both bricks if running a lot of engines.  I am a huge fan of smoke.

My understanding from the video is if I add a TPC 400 to the mix I will see increased smoke output at slower speeds.

Before I go out and buy a TPC can someone with a better understanding of the video tell me if I am correct? I have no need of the TPC for varying power because I only run command mode. Your knowledge sharing on this would be greatly appreciated.

Jeff,

If my understanding is correct, you won't see much, if any, difference if you are using full power to the track, as the sine wave would be the same at this level. However, using a TPC would bring you quite a few other benefits.  You'd gain a valuable extra level of circuit protection, and be able to lower the track voltage (if desired) without loosing smoke/coupler/performance functionality. You would also then be able to run conventionally using your remote at any time you wish, and be able to turn track power on and off from the remote too.  There are also quite a few other benefits of using a TPC. Have a look at the TPC manual on Lionel's website for the full details.

I use TPC 300 units with 2 x 150w transformers powering them. Like you, I normally only run with one transformer switched on most of the time, but the other is ready as a standby in case of failure or the need for more power at any time.

I concur with Nicole Jeff, I run command and especially in the case of your 2 180w bricks, I lowered my track voltage to 15.5v via the tpc and it eliminated the "arc welding" that commonly occurs during a derailment with 2 bricks going to the track. additionally a tpc runs MTH locomotives in conventional mode very well,even fires the coupler. Even though not ideal because of the lower starting voltage of a conventional loco it is possible to run  a conventional loco,and a command loco on the same track at the same time. A couple of keystrokes allows you to "toggle" between varying track voltage for the conventional loco or addressing the command loco. 

For some reason I couldn't get the video to work and a CW-80 and my MTH engines were not compatible.

 I tried the CW-80 on both conventional MTH engines and PS1 and PS2. Spurotic (can't spell that one)operation on all MTH.  Worked great on Lionel and KLine.  No more CW-80 for me.  Oh, by the way my old KW operated all my engines just fine.

 

Bud

Originally Posted by budgerman:

For some reason I couldn't get the video to work and a CW-80 and my MTH engines were not compatible.

 I tried the CW-80 on both conventional MTH engines and PS1 and PS2. Spurotic (can't spell that one)operation on all MTH.  Worked great on Lionel and KLine.  No more CW-80 for me.  Oh, by the way my old KW operated all my engines just fine.

 

Bud

Mth lists "compatible transformers" for their locomotives in the back of the owners manuals. A CW 80 is NOT on these lists.

I am curious to know if Mr. Reagan is using a meter capable of reading RMS voltages, or just a "regular" multimeter.

 

Bob Nelson, electronics guru on the CTT forum, says an RMS capable meter is needed to read the true output of the CW-80.  I'm guessing due to the chopped sine wave.  He put up a CW-80 correction table that shows when a multimeter is reading 15.5 volts the RMS volts are 18.2.  I'd like to hear what Dale H. or any other OGR forum electronics wizards have to say about this.

 

Pete

 

 

I use a Z-4000 to power my layout, on which I run mainly Legacy engines but also some MTH PS-2s.  The track is powered through the MTH TIU fixed voltage channel with the Legacy base attached to the outside rail. (I do not run in conventional mode except when I have to test an engine that has problems.)

 

I have sometimes wondered whether this configuration causes problems with TMCC or Legacy engines; certainly I have the odd smoke output problems with them but I have never noticed a coupler failure.

 

I've never had a smoke output problem with an MTH engine, however. That and the fact that the difference in performance shown in Mike's video is so great makes me wonder if I am missing a trick.

 

Since most of my engines are Legacy, should I be switching back to a modern Lionel transformer? I ask partly because I recall an MTH technical note about sine waves and early PS1 locos, which I have copied in below because it suggests that in fact using a Z-4000 to power track through a TIU results in something other than a smooth or "pure" sine wave - more an approximation of the chopped wave Mike's video refers to. I got curious about this because he does not mention using a Z-4000 with the MTH TIU, so here's the extract, with the part about TIU output in italics.

 

(BTW, I freely admit that I might be misunderstanding the significance of the reference below but I thought I'd ask the more knowledgeable people on the forum. However it might explain why the Lionel CW 80 is not on MTH's compatibility list and the operating issues RickO refers to in a posting above.)

 

Early Proto-Sound equipped engines (PS1) built in 1995 and 1996 suffered operating anomalies when used with "shark-fin" or phase control AC Waveforms found in the AC track voltage of what were then considered modern-type transformers. Older transformers, like Lionel's ZW model or MTH's then newly released Z-4000 employed a more "pure" sine wave form of current for which the PS1 system was specifically designed.


Because these newer transformers could cause the sound system to act irregularly, MTH chose to disallow operation with any transformer type affected by the shark fin wave form rather than suffer complaints that the engine was defective.


By 1997, software designers had pinpointed the shark-fin problem and resolved it through software and hardware changes in the PS1 circuit board. Consequently 1997 and later PS1 engines do not require the shark-fin transformer rejection needed in 1995 and 1996.


Users of DCS may have experienced the shark-fin rejection when attempting to run those engines on a variable channel. This is because the DCS Track Interface Unit (or TIU) does not employ the more expensive pure sine wave form of current found in the MTH Z-4000 and instead relies on the less expensive phase control AC waveform. While the TIU waveform isn't as pronounced as that found in those early mid-1990's transformers, the PS1 software will still reject the current and not allow the locomotive to leave the RESET state.

Last edited by Hancock52
Originally Posted by RickO:

I concur with Nicole Jeff, I run command and especially in the case of your 2 180w bricks, I lowered my track voltage to 15.5v via the tpc and it eliminated the "arc welding" that commonly occurs during a derailment with 2 bricks going to the track.

(snip)

That's why I don't especially like the TPCs. They have an old style breaker and it takes some current x time to trip them. I use a new ZW and it trips without the arc.

But if you use the TPC, you can buy these at American Hobby Distributors...they trip lightning fast. Programmable as to current trip and installed after the TPC.

 

http://www.amhobby.com/product...owershield_x_ac.html


 

Chris - thanks for posting.

 

Ever since I heard about the passive TIU connection, the final setup that Mike showed at the end of the video (TPC with two PH180s and a passive TIU connection) is what I planned to do for my mostly command control layout.  My question is if I use this setup for my main line tracks, but just use the PH180 through the TIU for my yard and roundhouse tracks, will I have any issues where the two systems are connected together with only the center rail isolated?  Since everything will be set at 18 volts, I would think there would not be any issue.  If I run my brother's or father-in-law's conventional engines, they would stay on the main line.

 

I also have two PH135 that I was going to sell, but I could save money by using them instead of buying two more PH180s.  I think mixing these with the above combinations should also work as long as everything is set at 18 volts.

 

Ron

A periodic wave has a peak value, RMS value and average value.

Meters and electronic circuits will respond differently to each of

these values. The video shows that the smoke unit and the couplers

are affected by the peak value of the input voltage.There are capacitors

inside the engine but if the have any effect on the smoke unit or couplers

is questionable.

 

The statement about the output of the old ZW transformer is incorrect.

The ZW has a 14 amp circuit breaker, total for all outputs. The transformer

can output the full 14 amps from one output or smaller amounts from each

output as long as the total is less than 14 amps.

 

YouTube video showing the output of the CW-80 on a scope.  This has been floating around for a while.  Note the delays on the bell button action AND the delay on ramp up AFTER you hit the direction button

 

 

Before DCC became popular in the HO/N part of the hobby, pulsed power packs were very popular with operators that wanted to eek a little more performance out of their trains.  Lionel and MRC started to apply the same technology to their "modern" power packs back in the late eighties/early nineties.  They did so partially for the same reasons and partially to avoid safety issues and reduce costs.  A PW ZW has a lot of heavy gauge copper wire with a lot of exposed material that would never get approval as a "toy" under todays CPSC/UL rules.

 

All of the pre war/post war power supplies were based on variable tap step down transformers.  All you are doing is stepping down the voltage.  By varying the sine wave's form in a modern electronic power supply you can modify the delivery of POWER (volts*amps) to the device by changing the shape of the waveform.  You can provide a quick jolt of higher voltage and then ramp down to keep stuff from burning up.

I am hoping Mike is following this thread as I have a question that he didn't address in the video.  He always described getting the chopped waveform using Powerhouses and TPCs.  But, since I run only TMCC, I use only Powerhouses and my Legacy Base.  Does this mean that I am running on full sine wave rather than a chopped waveform?

I run my legacy and dcs through my MRC 270 without any problems. I also lower the voltage to about 15 volts and have no trouble with smoke or couplers. I was wondering if this is ok And what kind of sine wave does the MRC give off. Everything has worked for the past 4 years so I guess I'm doing something right.

Originally Posted by Forrest Jerome:

my understanding is that if you run a 180 brick through a TMCC direct lockon you have chopped sine wave.


Not true. The lockon is just a breaker protected "direct" lockon. The power from the brick goes thru a standard relay which trips if the current rating of the brick is exceeded.

Originally Posted by PeterA:

I am hoping Mike is following this thread as I have a question that he didn't address in the video.  He always described getting the chopped waveform using Powerhouses and TPCs.  But, since I run only TMCC, I use only Powerhouses and my Legacy Base.  Does this mean that I am running on full sine wave rather than a chopped waveform?

You mean thru a direct lockon? Or hardwired to the track? Then the answer is yes.

Originally Posted by chuck:

(snip)

PH Bricks output a full sine wave at full voltage.  This is less of an issue for use with modern equipment as you always have the 18 volts on the track.

Less of an issue if you run TMCC you mean? I thought that about the video. I would not expect the older transformer to do well for everything new at only 15 VAC. I would use a sine wave transformer at 18 VAC and it should work reasonably well with TMCC.

Conventional is another story.

I had some wonderings about the "capacitor charges up to peak" comment. Was Mike saying that the AC is full wave rectified and the peak value of the chopped wave is stored in a capacitor? And that the average current into the smoke unit or applied to the coupler does not drain it below that peak significantly? So in the case of the conventional running, the smoke and coupler work much better with the lower voltages used when moving the engine?

And does all this also mean that the engines, coil couplers, smoke unit resistors, etc. are being designed with the chopped sine wave peaks in mind?

 

This all begs the question of why not rectify what ever the wave is and run everything at 12 VDC...except I guess for the power dissipation problems depending on how this is regulated.

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