Figured I’d better sound you guys out on this before deciding on which direction to take.
I don’t understand the preference for multi-train transformers. I’m sure I’m missing something. But if you have a 270 watt 2-train transformer, then each throttle has 135 watts, right? Then would a 270 watt 4-train transformer have 67.5 watts per throttle? And if so, how is that better than 4 separate 90 watt transformers? And why then is the ZW so highly rated?
I’m sure the forum members will straighten me out on this. Thanks.
If you are talking about the “new” ZW or Celebration Series unit, it is only a controller,not atransformer in the sense of the pw ZW, or Z-4000 to name two. The new ZW controller can be powered by one, two or up to four 180 watt PowerHouse transformers[“bricks”] servicing four separate throttles which will service four separate railpower districts if desired. The PowerHouses in a new ZW cannot be paralleled therefore when it is stated that the Celebration produces 720 watts that is a total of the four separate throttles [and of course, that total wattage is not available to a single throttle].
The single core, multi tap, 56 year-old post war ZW has four throttles, however the net output is 180-90 watts. As a result, you have that wattage available to a single throttle or allocated between multiple throttles if desired,theoretically about 45 watts per throttle if equal loaddemand existed[the input to the pw ZW is 270 watts, but output is only 180-90].
The Z-4k has two Railpower throttles producing 180 watts each.
edited @12:30p.m.
[the maxium output I ever recorded on any one of my four pw ZWs was 10.2 amps [a calculated 180+ watts@ 17+ volts] on a railpower district (14’x28’) with two long, incandescent lighted passenger trains pulled by a Proto 1.0 Ps-4 and a “J”. On occasion, after heating up from continuous running of the two consists, the ZW’s 10 amp external Potter-Brumfield breaker would trip].
Well you are correct in your thoughts on PW transformers. Most folks though probably used the 2 larger handles of the ZW for trains and the smaller dials for accessories and switches. The smaller dials would most likely but not all cases use less power than the “train” outputs. In the old ZWs the power is not divided evenly. So if handle A was using say 50w then 200w were available to the other outputs. So the outputs were using what they needed.
The newer ZWs do work as you posted. If they have 4 180w bricks then 180w is available to that output. No more can be siphoned off the others.
I agree that in the past why one would want to load share is beyond me other than you eliminate phasing issues because it was all self contained. And it came in a handy single box. I’d also imagine for the time it was suffcient for most layouts and had 4 adjustable outputs.
Transformers like the Z, ZW, and KW are have a single core and secondary winding with multiple variable taps off of the winding. In the case of the Z and ZW, there is a single 15A circuit breaker on the common return.
Because of this design, the output can be divided up any way between the four taps.
With my current set up and future plans for my layout, I’m using a Z and a ZW both. I have two main tracks. One is powered by the “A” handle on the ZW, and the other by the “D” handle on the Z. I will also have two yard-type areas, which will have a relatively low power demand. On will be powered by the “D” handle on the ZW, and the other by the “C” handle on the Z.
The other four power taps I have available will be used to power operating accesories. One will supply power for the O22 switches, and another for the UCS/RCS tracks. This can be surprisingly useful, as things like milk cars can be fussy about voltage(even from car to car) and it’s good to be able to tailor the voltage to each car.