CW-80 limited output

If you isolate the CW-80 (remove wires from it from track/acc), does it output expected voltage? If so you've probably got something on the layout sipping current

The transformer has not been on my layout.  It is bench-test voltage.

Does it work OK with a train set?

@RON ARNDT 091718 posted:

I have a CW-80 transformer that will only put out up to 13.3 volts on its track output terminals . The accessory terminals work o.k. and the voltage can be varied without a problem.  What would be limiting the current output on the track terminals and is it an easy fix?

Ron

Part of this may be an expectations issue. Yes, the label says 18V. The problem is, that is the core transformer source measured AC RMS voltage. Then you have this TRIAC based chopping circuit, that further distorts the waveform and even max wide open, you never get out of the circuit what you put into the circuit for voltage. Add on top of that, what your meter might read with a distorted waveform and yeah- 13.3V would not be the error you think it is. I say this because a common complaint is from folks that run MTH Loco-sound engines, they cannot get enough voltage to the track so they complain about slow loco operation on a CW80 (yes, turning off speed control in Loco-sound works around this problem).

Again, while that seems a low value, you stack up potential measurement error from the distorted waveform, and the fact on it's best day they likely cannot output 18V RMS true sine-wave just because of known distortion and losses. Here are some topics about low voltage https://ogrforum.com/...nel-cw-80-output-15v

Here is a measurement by @gunrunnerjohn saying 16V https://ogrforum.com/...82#25504494581326982

Just in case that's not the answer and your transformer is under-performing on a channel-

So if the accessory output outputs a higher measured voltage (obviously adjusted to max possible voltage) that sets the bar for what performance one can expect from the circuit. Then if the track channel is not capable of the same output voltage maxed- suspect the TRIAC has been damaged.

Discussion of new CW80 VS old compares the 2 types and lots of details https://ogrforum.com/...0#161208612964634320

Last, again, thanks to @gunrunnerjohn who posted the schematic for the old style CW80 here https://ogrforum.com/...9#168247930405103369

Old CW80 uses BTA24-600CW TRIACs, one for accessory and one for track output.

Again, bottom line, you either are just seeing the limit of the old CW80, or if the channel is not 100% compared to the accessory channel, then the top suspect is the BTA24-600CW and the track one is the right most one.

Thanks for the advice.  My voltmeter measures accurately when I use it on my other CW-80s, so I suspect that it could be the BTA24-600CW for track power.  
Ron

FWIW...Extracting the transformer from the CW-80 and running it as a pure sine-wave source, I measured 19.4 VAC with no load and 19.1 VAC into a 10 ohm power resistor to draw almost 2 Amps.  Not too bad!

Isn't there an output setting on the cws? I remember someone posting about that a while ago that you can set the max output to desired level. I belive it's in the instruction manual.

That's on the Accessory side.

Jon