Lionel CW 80 low voltage

[tritimmy]

Hello

I purchase (Used) a Lionel CW 80 transformer, serial G0906.    Checking with Lionel, it's one of the good ones.  I bought last Christmas, never used it, put it into storage for later use, and only today tried it out.

That said, the AC voltage to track only goes to 9.7 volts.  My AC voltage test meter is working properly.  I can set the accessory voltage to 12-14 , so that looks to work well.  The green light seems to work properly.  The fan comes on every time after about 45 seconds of my turning on the transformer.

I called Lionel, who said this can not be repaired as the triangle screws that hold the CW 80 together need to be removed.  Lionel says they (Lionel) do not have the tool to do this, which if true, surprised me.

Has anyone seen this situation of low voltage, and if so, how an I get it repaired?
Thank You

Tim

[lionelsoni]

Do you have a "true RMS" voltmeter?  Most AC voltmeters assume that you are measuring a sinusoidal waveform, which the CW-80 definitely does not put out.  Here is a correction chart for use with an ordinary voltmeter:

Meter           RMS 
  0             0
  0.5           1.6
  1             2.7
  1.5           3.7
  2             4.6
  2.5           5.4
  3             6.1
  3.5           6.9
  4             7.5
  4.5           8.2
  5             8.8
  5.5           9.5
  6            10
  6.5          10.6
  7            11.2
  7.5          11.7
  8            12.2
  8.5          12.7
  9            13.2
  9.5          13.7
 10            14.1
 10.5          14.6
 11            15
 11.5          15.4
 12            15.8
 12.5          16.2
 13            16.6
 13.5          16.9
 14            17.3
 14.5          17.6
 15            17.9
 15.5          18.2
 16            18.5
 16.5          18.8
 17            19
 17.5          19.3
 18            19.5
 18.5          19.7
 19            19.8
 19.5          19.9
 20            20

You can see that when the CW-80 is putting out its full 18 volts, an ordinary meter (which I'm assuming is what you've got) should read about 15 volts, which is not too far from what you're seeing on the accessory output.  The simplest explanation for the track voltage's being so low (actually about 14 volts RMS) is that the handle is attached to its shaft at the wrong angle.  I don't have one here; but maybe you can see a way to get the handle off and reattached at a different angle.

[gunrunnerjohn]

Lionel simply doesn't want to fix those, the lame excuse of not having the screwdriver is about as bad a reason as I've ever heard!  Is it their name on the transformer or not?

[David Barker]

[tritimmy]

Bob,

First, thank you for the chart.  It's an excellent reference  My Meters are FLUKE and Craftsman digital VOM''s.

Secondly, the transformer itself looks to be in perfect physical condition.  And, as adjusting the accessory voltage output was done correctly using the same throttle, the throttle apperas to be in-line and working.

 

My thought:  I'm guessing when the unit was made, they tapped the wrong line from the output side of the transformer for the track voltage.  If, as I believe, they took the 50% tap on the output side for the track (many transformers are wired for multiple taps), that would line up with the readings I'm getting on the track output.  (I was trained as an Electrical Engineer, so I know a little about transformers, etc.)

 

What's surprising was Lionel's response to my request that I would pay to have it repaired.  They were polite on the phone.  But after they told me that the tool (a screwdriver of sorts) needed to take apart this transformer was only in China, they lost me.  They politely then said that i could always buy another CW80.

I can always use this unit as an accessory power for later layouts.

Thank you again for taking the time to send along the chart.

Tim

 

 

 

 

 

[gunrunnerjohn]

So Dave, did you have something to say?

[Texas Pete]

tritimmy

...I called Lionel, who said this can not be repaired as the triangle screws that hold the CW 80 together need to be removed.  Lionel says they (Lionel) do not have the tool to do this, which if true, surprised me...

This is some of the worst bull corn I've heard of, outside of Washington and Austin.  Lionel should be ashamed and embarrassed.  Search on "triangle screwdriver" or "triangle screwdriver bit" and you'll know what I mean.

Meantime, the handle of a CW-80 is a friction fit, and it can be removed by pulling it straight out from the transformer.  Since the handle is keyed to the potentiometer by a flat on the shaft, I suspect that the nut holding it to the transformer body has loosened and the potentiometer has shifted position.  This happened on one of my CW-80's and I was able to fix it without opening the transformer by holding the shaft with a vise-grip set on "gentle," and tightening the nut.

Pete

 

[gunrunnerjohn]

You can also make yourself one of those screwdrivers using an old Phillips head screwdriver and a bench grinder.  It's really not that hard, just make sure to keep the tip cool with plenty of dips in the water as you shape it.

[lionelsoni]

Two more thoughts:

Did you have the CW-80 loaded when you took your voltage measurements?  The pass element--a triac--is shunted by a capacitor, which can leak some or all of the original sine wave to the meter if not loaded.

Did you use the same meter for both outputs?  Since non-true-RMS meters use a proxy measurement expected to be proportional to the RMS value, one meter might, for example, be measuring the peak and the other the rectified average.

If the different readings from the two outputs were due to either of these circumstances and you can get agreement between the outputs by taking them into account, then the problem might be the handle position after all.

[tritimmy]

Hey all

Thank you for the help.  To answer your questions:

A)  The handle: yes it appears to be in the correct position  Nothing loose.  And again, I can adjust the accessory voltage output properly with the handle. 

B)  Yes, I used the same meter for all measurements.  i asked Lionel abut loading the unit while measuring.  They said that loading it was not necessary to measure the outputs.  Still, I'm showing half the output it should have at the track output.  Accessory output is right where it should be.

C)  It seems that indeed when this transformer was made at the factory, that they did wire the incorrect tap for the track output voltage.  That's the only scenario that makes sense.

D)  I did buy this used, and take responsibility for not testing it at that time.  When I called Lionel, I called with an offer that I would pay to have it repaired.  That's when they (Lionel) told me that their supervisor in York told them that Lionel does not have the screwdrivier needed to take the CW 80 apart.

As an aside, after a 35 year hiatus, I am returning, albeit slowly, to model trains.  It's been a learning experience, learning about the new companies, websites, ...........and especially customer service.

Thank you all
Tim

[lionelsoni]

B)  It wouldn't hurt to connect a lamp across your voltmeter leads to see whether it makes a difference in the measurements.  There have been reports of (high-impedance) electronic reversing boards' not recognizing voltage interruptions when connected to CW-80s.

C)  If you set each output to the same voltage (with a load on each), the behavior should be different if the triacs are connected to different transformer taps.  If the taps are different, there should be an alternating voltage between outputs, since one is 20 volts RMS switched on late in the half-cycle and the other is 10 votls RMS switched on early in the half-cycle.  If the taps are the same, the waveforms should be the same; and there should be no voltage difference.

D)  I'll bet you could make the screwdriver easily.  Get a cheap Phillips, cut off the tip, and grind the end down to the right-size triangle.

Do the output voltages contain any DC (when the whistle control is not pressed)?  It's possible that one triac is not firing for both polarities of the waveform.