CW80 & Z1000 Behavior

Mike,

The reason for this is the electronics in the newer transformer are not doing a full sine wave it a pulse because they are digital.

Type R

CW80 and Z1000

Well they tried to round it off but it still has the flat spot.

I would add to the video that @ADCX Rob posted is that the "peak" voltage (highest point of the nearly complete sine wave) is 18VAC.

I will get to your main question about the train slowing down in curves at the end, but a little more info.

The flat spots are caused by the electronic switches being used to chop the wave. As the video shows, when pressing the horn button, or the bell button, the size of the flat spots change from being the same size, to different sizes. This results in a net plus DC bias, or a net minus DC bias - duplicating what the ZW did with the diode for the horn, and the sound activation button add on accessory for the bell does.

Below is a block diagram that I believe shows what is in chopping transformers. Caveat - this is my opinion, but may not be exact. I used 20VAC as to output of the transformer's "transformer component" to allow for some drop in the electronic switches and get 18VAC max.

So, again with the caveat this is my own interpretation of what is being done, the chopping transformer puts out the same energy as a pure sine, but puts out the energy in smaller bursts by sending a higher voltage than the pure sine wave, but for a shorter duration. For modern DC can motor engines that full wave rectify the incoming DC and may even have a capacitor on the DC for temporary energy storage, all works fine. But AC motor powered engines may not actually see all the energy, thus may not have all the pulling power. The AC motors may not "see" all the energy because the magnetic fields that make the AC motor work are not sustained as long as when electrified by pure sine wave. This reduction in pulling power, small as it may be, may be enough to show up when your train needs a bit extra pulling power to overcome the extra friction when wheels are pressed against the rails in a turn.

Hope I haven't showcased my ignorance too much!!!

MED posted:

I would add to the video that @ADCX Rob posted is that the "peak" voltage (highest point of the nearly complete sine wave) is 18VAC.

The peak is actually about 25 volts, depending on the line voltage to the primary, for 17.9-18 volts RMS output. This is evident on a scope, as well as using some simple math.