Chopped Sine Wave Question

Jeff

Keep up with this thread because I am sure more will be found out about the differences. I really like my Z4000 transformer and it works very nice but there are some differences between operations of the two sine waves. It just depends on how you want to operate your railroad in the Conventional mode. Remember that this does not affect the Command and DCS mode of operation only Conventional operation.

In Mike's video he states you can use a PW ZW with a TPC 300/400 or a PowerMaster to create a chopped sine wave. I'm familiar with the TPC's but not so much the PowerMasters. Is he saying the PM from my TMCC would work or is there a different PM I would need??

Jeff with trainmaster you get a cab1 and a command base. Although the powermaster and command base look similar they are 2 entirely different products. The powermaster comes in 2 flavors. A 135 watt version and a 180 watt version. You can run trains conventionally with the cab1 and the powermaster without using a command base. If you need switch and accessory control then you would also add the command base. The powermaster when set to conventional will vary the track voltage or in command come up with full voltage. These 2 will not work with a legacy system without a powermaster bridge. There is a new powermaster due in the spring that will be a legacy powermaster. Just to add all 3 need power to them just like a TPC.

Ron

As always, Thanks Ron!

While not a scientific experiment I did have a chance to fool around with one of my TMCC locos. I've been running it with a PW ZW and Legacy. Today I pulled out the CW 80 and ran that with the legacy.

I can confirm the smoke did the like the CW better as did the couplers. Interesting!

<The shape of the chopped sine wave seems to me to have some of the same characteristics of pulse DC power that was popular for HO operation a few decades ago.  Both have a sudden burst of voltage and both make the trains perform better At low speed.

Earl>

The better HO throttles would use a 20-30 volt narrow pulse to get the motors turning very slow. Since torque and voltage are both a force the hi voltage spike would generate more torque. In the AC realm a higher voltage pulse to the motor can be generated by starting the polse not at the zero crossing of the AC but in the middle of the alternation where the voltage will peak around 24 volts. Since an alternation is 8.3 milliseconds the pulse should start at around 4.1 milliseconds and expand in both directions. This method generates more torque required for slower speeds.

Gary E

MXRobotix

I have a pair of old, HO/N power supplies like that from 1980s-early 90s and use them to drive my Superstreets loops.  I've removed the recitfiers from all my vehciles so they run on DC only (but thus backup when you reverse polarity).  These power supplies "get their attention" better - with only four tiny wheels, one or two with traction tires, and those minute center pickups, low-resistance electrical contact is not a 'Streets vehciles strong point.  They also provide much better low speed running: on AC or standard DC most Ss vehciles will go smoothly only at about 40-45 mph, but with these, down around 30-35.  Not as a big improvement as I'd like, but noticeable.

Reading the thread over again, was the question answered what waveform comes out the fixed outputs on the MTH TIU?  Pure or chopped?  Even if the input is a pure?

Definitely not a test by any means, but I do recall an observation running our newest engine - Legacy Lionmaster T1 (w/ whistle smoke unit) on our under the Christmas Tree layout using a pure sine wave transformer.  The transformer was the MRC single throttle Pure Power AC.  I thought the smoke output seemed anemic.  I'll have to try an experiment with a CW-80 I should have from a Lionel (Thomas) set.  I don't think I have any other chopped sine wave transformers than that.