I'll say it again: Accessory voltages do not have to be in phase with track voltage. In fact, there can be slightly less voltage drop if they are out of phase with the track. It is also true that the accessory voltage does not have to have the same voltage, frequency, or waveform as the track voltage. For example, my turnouts operate perfectly well on DC capacitive-discharge sources.
Consider the three utilization-voltage wires coming into your house: They connect to a center-tapped 240-volt transformer secondary somewhere outside. There's 120 volts between each of the black or red wire and the white wire, the neutral, which connects to the center tap. Half of the 120-volt outlets in the house are fed from black and half from red, 180 degrees out of phase with each other. Any currents drawn from black or red and returning to white are also out of phase and cancel in the white wire. The worst case, that you are drawing all your current from one or the other of black and red, is that the current in the white wire is the same as the current drawn from the other wire. So the white wire doesn't have to be any bigger than the other two.
Furthermore, if you are drawing some current from each phase--almost always the case--the voltage drop in the white wire is less than than in the other two, because the return currents cancel. This is the main advantage that we can exploit on train layouts, by using the outside rails as the common return for both train and accessory currents, out of phase with each other.
If we used the simpler, two-wire, circuit that many other countries have, it would actually require about 67 percent more copper than the three-wire circuit to deliver the same power at 120 volts. And we wouldn't have the voltage-drop improvement as a side effect. (They get away with two wires because they generally have almost twice the utilization voltage that we do and therefore about half the current.)
Bob Nelson
YES on phasing. Common is U. I use the variable side of the KW's and set the voltages at the best operating voltage. ZW's phased with these for track voltages. All transformers I used are phased together. I use about 14V for switches. Makes them open and close fast and especially those working together.
God bless TCA 05-58541 Benefactor Member of the NRA, Member of the American Legion, Retired Boss Hog of Roseyville , KC&D Qualified
Thanks guys ….
rivesmAll other accessories are connected to the KW's 14 volt taps.
That's fine for accessories w/o grounds common to the track.
Rob
Ok….let me take a shot at your question. At present my 4 switches are connected to a 1.8 amp Lionel accessory transformer and I am using the outside rail for the negative.
All other accessories are connected to the KW's 14 volt taps.
That's great! Me too!
What are you using for common, and what voltage range are you using for the switches? Is the KW phased to any other transformers on your layout?
Been using KW's to power switches and accessories for years.
The problem with the 14 volt range on a KW is that it can't be used with the commons for switches(or other accessories) on the track. Unless the KW is dedicated for two fixed(6 volts and 20 volts) and two variable accessory outputs(A-U & B-U), it's not very versatile for accessory use.
If one is using a KW to power two tracks ….. how much "capacity" can the 14v fixed component handle.
Planning on four (4) 022 switches, 8- 10 streetlights, 2 or 3 signal blocks, 3 or 4 illuminated buildings and a coal loader and a cattle loader.
Thx for helping a novice. Guess my basic question is "are there advantages to using another transformer?"
servoguy...you could buy two 1033s...
Another great idea, since that is just about what a TW is(the second 1033 inside the case has fixed taps only).
If you are patient, you could probably get a KW for about $50. Or you could buy two 1033s for a lot less than that.
They are quite plentiful and affordable.
The Lionel TW is probably the most versatile transformer for dedication to accessories.
I am looking for an accessory transformer and need advice. I had purchased a Lionel 1.8 amp unit but am not satisfied as I feel I will end up with more accessories than it will handle. In fact, I already have.
Looking for a unit that will handle four(4) 022 switches, 8- 10 streetlights, 2 or 3 signal blocks, 3 or 4 illuminated buildings and 3 or 4 other things I "ain't" thought up yet.
Want something basic and simple and reasonably priced.
Thoughts?
Thanks in advance
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