I am refurbishing my KW and have a question on the voltages. On the first fixed voltage terminals, I get 6.3v, on the second, 13v and on the third, 19.3v. On both the A and B variables, at full throttle, I get 19.3v. Are these voltages within the Lionel Specs? They seem slightly low to me.
Thanks for your inputs,
Jim Lawson
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Here is part of the voltage table from the transformer section of the 5D test set manual.
Your transformer seems to be within the limited specs they give.
Those voltages look good but the real test of a transformer is the voltage and amperage output. IMO, the KW is a fine transformer design and one that is often under rated. I've run two long trains (4 motors) with one and it did it with ease.
One weak spot of the KW is right at the shaft where the pickup arm connects to the fixed wiring. There is a spring that holds all of that together, but I've had several of them that had a significant voltage drop in that stack, several times it was over a volt with a moderate load of around 5 amps on the transformer. Needless to say, the hub got pretty warm in a hurry! I've had 100% success hitting that stack with DeoxIT D5 and working the levers back and forth a few times, amazing stuff. It really does improve the contact properties.
Keep in mind, the voltage range printed on the rear panel says 20, but under load it is more like 18 volts maximum.
Another point on the maximum voltage, it is obviously directly related to your input voltage. My power here runs fairly high at 127-128 VAC at my outlets, however I've seen folks that are a lot closer to 110 VAC at the outlets. That 15 volt difference will translate to several volts difference in the max open circuit voltage out of the transformer, the windings are roughly a 6:1 ratio. If 120 VAC in gets you 20V out, 110 VAC in will only get you around 18.3V out.
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