CW80 Small Adjustment potentiometer across throttle Pot.

Any answers for this

Shawn,

    The best way to repair or adjust a CW-80 is to put the CW-80 in the circle 7 file as soon as possible and upgrade to a better Transformer, say Z1000 or better.

PCRR/Dave

Shawn,

If you have a small boat or canoe, the CW-80 may work as an anchor. For myself, I wouldn't have it attached to the boat when I threw it overboard. 

Like Dave above, my Z-1000 is working just fine.

Dave,

i own 2 zwl's, 5 zwc's , 8'zw,s and others. I use this as a small test transformer...and recently changed the fan. I used the pot to realign the zero off point. The transformer is not the best...but, there is something I like about it.  Getting another transformer is a good suggestion....but, it is so simple to fix...and use as a extra...

Shawn,

   Not so simple when you have one burn up right on your layout power station, circle 7 that piece of junk, and remove any further danger & problems.  I will probably be attacked for this piece of advise, but I would not own one if someone gave me one, and I have given a few away, brand spanking new.

PCRR/Dave

Some funny answers on the CW80. Although the later ones were better made than the ones of say, 4-6 years ago, the one I got packed it in quickly. Problematic and rather difficult to repair without a longer triangular screwdriver to get beneath the outer case...What I liked about this "Circle Seven" doorstop was an adjustable accessory voltage output...  Give it credit, tho' - it is an attractive piece of effluvia!                                              

Shawn,

Have you seen Dale Manquen's schematic on trainfacts.com This was created with the first version which had the hots tied together.

So, funny. I was watching a old Christmas movie with Peter falk on you tube last night. Guess what made the store cook!

Virginia65,

    Never keep a Lady or a Transformer that looks beautiful, and is not performance oriented, both are usually dangerous items.

PCRR/Dave

I have a few CW-80s. They are handy for a variety of uses like accessories, lighting, test bench, etc. I have all the later version, not the first version with the shorted A terminals. They are repairable and have a really great transformer in them. Dale M tested the transformer and it was quite capable of more amps than it is required to supply. If fact, I was thinking I would strip all the electronics out of one and use it for a Legacy brick if I needed one. I think it also has a fuse inside the winding for over heating safety, but if it goes, the transformer is toast.

shawn posted:

Any answers for this

To the actual original question, I would guess you would have to use a voltmeter on your track/transformer output and carefully adjust the pot until the meter reads zero.  

Pine Creek Railroad posted:

Shawn,

    The best way to repair or adjust a CW-80 is to put the CW-80 in the circle 7 file as soon as possible and upgrade to a better Transformer, say Z1000 or better.

PCRR/Dave

Dave, I've seen your posts to this effect many times, and understand you had a catastrophic failure of a cw80 at some point.   After studying the schematic provided by Dale M.  I can't find any fault with the design of the cw80.  Sure it is a cheap starter transformer, but I don't see anything that would make one triac device any better than another.  The only point of catastrophic falure I can see is if somehow the 8 amp fuse failed in an on position, but a fuse failure of this type is insanely uncommon and could happen to any product.   I don't have a schematic of the Z-controler, but I can't think of another way for it to work than to use triacs and an op-amp to adjust the triacs to zero-crossing.  I don't know that would make another product that most likely is almost identical to be any safer.  Perhaps the MTH product uses a better quality of parts that are less prone to failure?  

As a separate topic, I see suggested that folks use the wall pack direct as a constant power source.  I'm curious if anyone knows if the circuit protection is on the controller or the wall pack on these units?  The cw80 does not appear to have anything to protect it's self from shorts, or to protect train electronics from spikes, does the Z-controller?  If I had to guess, a TVS and fast acting circuit breaker on the output side of the cw80 would probably eliminate it's problems.   

JGL

Edit:  I thought about it a little more and figured I'd add a thought or two on other causes of catastrophic failure.  I suppose the triac's could lock in an on position but this would just leave full power to the output, this is the worst that could happen with any failure on the electronics side.  Triacs normally fail in an off state.  The  only other failure point I see is there being no protection on the input side of the transformer, so, in theory if the transformer's windings were bad it would sit there smoldering until your line breaker/fuse popped.  

Anyway, guess the point in all this is, if you're going to toss a cw80, choose instead to toss it in a box and send it to me.  I'll pay the shipping.  email is on my profile for anyone that wants to send me stuff.