PW ZW can't divide/assign current based on "channels". You can vary the voltage on the four taps but the current will flow wherever the load is. Total sustained output is around 180 watts for all four channels BUT the ZW can allow a transient peak above the nominal 180 so long as the peak doesn't exceed the limits of the internal breaker (time and/or current). The modern supplies are 180, period. Equipment start up often involve "peaks" that fall back once the device is running. It sounds like you are pulling just over the rating under some circumstances and that's why the PW equipment doesn't trip while the modern stuff does.
Originally Posted by Dale Manquen:
Just for completeness here, I think we should include a quick description of the Z4000's technology.
I don't own a Z4000, but I believe the voltage control is achieved by chopping the incoming voltage at a high frequency, and then modulating the width of each of those chopped packets. The packets are then "glued" back together and the high frequencies from the chopping are filtered out to yield a smooth sinewave. This type of circuit works at a much higher frequency than a simple shark-fin control, but since the controls are all ON/OFF switching, there is only a small amount of loss as heat during the transitions.
I believe this fairly common technique, which is not too unlike the switching power supplies in all of our computers, is unique to the Z4000 in our train world.
Wow. Very interesting.
How I wish I still owned an oscillascope.
Chuck, i think you have it. Thanks.
Well, I have three "circles." According to your formula, I need 4 more bricks.
My comment wasn't a suggestion for power, I was only mentioning how the circuit breakers popped on my old layout.
BTW, the reason I powered each track with 2 - 180W Bricks and a TPC 400 is because some of my trains had 2 or 3 powered units with 8 to 12 (sometimes more) passenger cars. There were also times I ran two trains on the same track. The downside was that all that current was hard on the Atlas switches. I eventually had to rewire all of them, but after that everything was fine.
Originally Posted by Lee Willis:
Originally Posted by Dale Manquen:
Just for completeness here, I think we should include a quick description of the Z4000's technology.
I don't own a Z4000, but I believe the voltage control is achieved by chopping the incoming voltage at a high frequency, and then modulating the width of each of those chopped packets. The packets are then "glued" back together and the high frequencies from the chopping are filtered out to yield a smooth sinewave. This type of circuit works at a much higher frequency than a simple shark-fin control, but since the controls are all ON/OFF switching, there is only a small amount of loss as heat during the transitions.
I believe this fairly common technique, which is not too unlike the switching power supplies in all of our computers, is unique to the Z4000 in our train world.
Wow. Very interesting.
How I wish I still owned an oscillascope.
You can get some pretty nice scopes for not much money. I bought a Rigol 1102E at the Dayton hamfest last May and like it very much. I still have an old Tek scope or two, but use this one mostlywith all it's features.
What type if sine wave is produced by the Atlas 80 watt transformers?
Pure sine wave. The knob moves a wiper arm across the windings just like a postwar transformer.
Have you actually tried the atlas 80 watt?
It might work just fine.
Originally Posted by Flash:
Have you actually tried the atlas 80 watt? It might work just fine.
Yes, I bought it to run the CC Berkshire set at some charity events and around the Christmas tree. I did try the Atlas transformer with my Williams Scale GG1 which was upgraded to TMCC and ERR Cruise and the engine seemed to function fine.
Did you notice after the transformer was switched to the 1033 and the unit was started, and the smoke turned on, that there was a lot of smoke coming out of the unit. Then Mike hit another sequence of buttons and the smoke stopped. Then he stated that the smoke was from the CW-80 (which was not connected at the time). I watched it twice.
Mike correctly stated the work performed is the area under the curve, but incorrectly stated that a quarter curve chopped wave does more work. Clearly there is more area under a half curve then a quarter curve given the voltage peak is the same.
Certainly the electronics may be designed to work with chopped, but I find it hard to believe that a heating element that sees the same voltage peak for a shorter period makes more smoke.
A capacitor that sees 18-16V for 2 msecs (Chopped)will not have stored as much potential engery as a capacitor that sees 16-18-16V for 4msecs (Fully). Just looking around the peak. Interesting video. G
