Lionel KW transformer - is wattage (per track) dependent on number of tracks?

  If I’m not mistaken, all the power of the KW is available to be used however you like...all on one handle, or any variation of load split between the two handles up to its max output.

  As a side note, the stated output of the KW, and most older generations of transformers, is optimistic at best.  

Tom

I don't know for sure, but based on a schematic I found it looks like each handle runs along the same winding and share a common tap, so I'd guess, yes all 190W is available on one handle.

https://images.app.goo.gl/eaV62c58mW7oES7XA

@CurlSnout posted:

Another question, since I'm at it: I'm planning on running, for each loop of track, a main bus line and multiple power drops spaced at more-or-less regular intervals.  Might I just be better off going for ONE of the newer 'big' transformers, and using that to run both loops on the new layout?  The loops on the new layout will each be about 69' total length.

One option would be to use the KW for loops 1 and 2 and use your 1033 or GW-180 for all of the accessory power on the board.

My MTH locos only draw an amp or so each - so figure 30W per locomotive conservatively.  Postwar stuff is another story.  I think you shouldn't have two much trouble running 3 or 4 locos from a KW if they are a mix of modern and postwar.  Depending on how many passenger cars you have that can change things - but if you switch those to LED lighting, that will remove them from the equation almost entirely.

Note that the KW doesn't actually deliver anything close to 190 watts.  Postwar transformer are rated on input power, considering an efficiency of maybe 70-80%, the actual output power is around 140 watts.

Modern transformers like the Lionel ZW-L or the PowerHouse 180 are rated on output power.

Thanks, guys.  Good to know about the difference between wattages at which a transformer might be 'rated' and what it is actually capable of delivering.  My question had less to do with the actual absolute values of the wattages, and more to do with whether the watts available from the KW could ALL go to one track (assuming the other 'channel' remained empty) - or if the total available watts from the KW would be split in half, irrespective of whether one or two trains were operating.

I had considered buying a ZW-L to run both loops on the new layout, but since the ZW-L delivers a chopped sine wave it won't be compatible with my BL-2 - and it seems like having a ZW-L to run just one loop would be overkill.

So my current thinking is to use the GW-180 to power one loop, and look for a reconditioned KW, or possibly a ZW (275 watt) unit - in order to get a smooth sine wave with which the BL-2 should be happy on the other loop.

Hi-Ho,

Sam

The postwar KW or ZW can deliver all it's power to one output if desired.  Both of those transformers have a single core with all the controls sharing the same core and tapping the power necessary.

@CurlSnout posted:

If I use the KW to run only ONE train (I have the GW-180 for the other loop), are all of the 190 watts available?  Or, do you only get 95 watts per track (0.5 x 190 watts), regardless of whether you run one or two trains?

All 140 watts output(190 is the input rating) of the KW is available in any combination, up to 19-20 volts. You will notice an improvement over the 16 volt 65 watt output of the 1033.