On Sunday, February 2, 2014 11:35:58 PM UTC-6, wrote:
I realize that this is probably not the correct forum to ask this question, however with so many talented people out there who subscribe to this group I was hoping that someone would either know the answer to this or perhaps be able to direct me to a more appropriate group. Some time ago I picked up a box of old mid 1950's Lionel trains, track, two small adjustable train transformers and some accessories. I just got finished going through the equipment, and with the addition of some new parts and labor have restored everything to good working order once again. The engine is a 2055 and it is married to a coal tender that has a whistle inside of it. The train motor operates on 0 - 16 VAC, but the whistle in the tender, (which is a small fan motor which blows air through some portals), I am told operates on DC. This DC voltage is somehow superimposed on the AC. The correct transformers for this set have levers that you would move to apply the DC to the track, operate the tender motor and blow the whistle, and would be either the KW or the ZW, neither of which came with the equipment in the box. After completing repairs, I confirmed that the tender whistle was working by taking the tender to a train show and trying it out on a test track. Since the small transformers included with this set get hot and are too small I've been using my bench variac through an isolation transformer to test the train. I tried to see if I could blow the whistle by connecting my DC power supply to the track, but the current peaked at over 6 amps and took out the power supply fuse twice. The variac didn't like it either and started to growl. I figure the train motor as well as the transformer secondary must be loading the DC supply heavily, and perhaps vice versa. I'm not really sure whats happening here. I subsequently found a larger transformer at another yard sale which is able to handle the current required to run the AC motor in he engine, but there is no whistle provision. I've set the train up in the play room temporarily with the larger transformer but it would really be nice if my 4 year old grandson could hear the whistle blow. Is it possible when the whistle is blown that the DC is being placed in series with the AC? Sounds crazy but I never tried that. This couldn't be very complicated. What am I missing here? Thanks, Lenny

You can't put the DC in parallel wiith the AC. I would put the DC supply in series with the AC supply from the transformer secondary that is running the engine. You might have to reverse the polarity of the dc to get the whistle to work. Let us know if this works. OR, contact a member of your local toy train club and talk to them to find out for sure how this should be connected.