Three semi-related questions I've been unable to find the answer for. (And by "unable to find" I mean "exhausted every possible online resource over 7 hours of searching.") Since from what I've found I 'think' Lionel "oversold" the power of their MultiVolt series of transformers, but I've been unable to find anything on their actual (which I think is the same thing as continuous) power output. Also - anybody know why Lionel uprated the power of their transformers from 1917-1921 and than dropped them back again? Actually different designs in each period, or did the higher power output cause problems? I know the 840 power station was designed to house two transformers, and the base was removable, but could you (in theory) mount an additional (or more) transformer(s) in the center portion of the building for use with accessories and such that don't require frequent access (and are the side portions separated from the center portion by a solid plate, or is it open? And is connecting two transformers in series to double the number of output watts viable, possible, or a terrible idea? (Also discovered - a 4 car state set draws around 67 watts from the lighting alone, and a 440 signal bridge draws 27 watts directly from the track. It starts to add up even for track power alone. A 150 watt (rated input) Type K transformer runs out of power pretty quickly. I'd assume you'd want maybe a 80-100 watts left over to run duel-motored standard gauge engines with heavy trains?) Sorry for so many questions so quickly, but I'm pretty clueless over a lot of this.
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@CSEverett posted:...is connecting two transformers in series to double the number of output watts viable, possible, or a terrible idea?
Terrible idea for doubling watts, terrific idea for doubling voltage. Connecting two transformers in parallel to double the number of output watts is viable.
As an electrical engineer, let me state that connecting two (or more) train transformers in series is an ABSOLUTE NO! At best, it would double the voltage and would likely overheat and blow everything connected to it including motor windings, lamps, and electronics if you are using modern equipment. It is possible to connect multiple transformers in series if they are phased correctly, though I would strongly recommend the use of a bigger transformer as the UL listing is not based on this case.
In general, you should not run a transformer at its rated wattage on a continuous basis. I would recommend no more the 75 or 80%. Running at transformer at its full-rated power will shorten its life.
Finally, I would not run transformers inside a power station. Having the transformer in free air, especially a vintage one, will allow it to perform at its best.
Be safe!
Tim
@PittsburghTim posted:As an electrical engineer, let me state that connecting two (or more) train transformers in series is an ABSOLUTE NO!
Lionel in the 1980s recommended using two 4090 transformers wired in series to run the 783 Hudson at up to 21 volts.
@PittsburghTim posted:As an electrical engineer, let me state that connecting two (or more) train transformers in series is an ABSOLUTE NO! At best, it would double the voltage and would likely overheat and blow everything connected to it including motor windings, lamps, and electronics if you are using modern equipment. It is possible to connect multiple transformers in series if they are phased correctly, though I would strongly recommend the use of a bigger transformer as the UL listing is not based on this case.
There's nothing wrong or inherently dangerous about connecting the two transformers in series. Your comments about excessive voltage are well founded, and is the reason it's probably not a practical configuration.
@PittsburghTim posted:In general, you should not run a transformer at its rated wattage on a continuous basis. I would recommend no more the 75 or 80%. Running at transformer at its full-rated power will shorten its life.
Since we're talking prewar and even the postwar transformers, the power rating is input power, so 75-80% is the absolute maximum output power you'll get.
@PittsburghTim posted:Finally, I would not run transformers inside a power station. Having the transformer in free air, especially a vintage one, will allow it to perform at its best.
This would be very dependent on the load on the transformers. Assuming an 80% efficiency, somewhat reasonable for the old transformers, about 20% of the input power is converted to heat. For a 150W transformer running with a maximum load, that would be about 30 watts of heat. So, consider a 30W bulb in there and consider what the temperature rise would be in the space provided.
Truthfully, I'd not try to stick the transformers in there anyway, and I'd be using modern transformers for fixed power output.