MTH bump and go trolley power question

You likely have a DC can motor with a bridge rectifier in front of it to rectify track AC to DC.  Track DC remains DC through the bridge.  But with AC through the bridge you are pulsing the motor 120 times per second.  So while the average torque to the motor is the same (and hence the two versions run at the same speed), the AC version provides an underlying vibration or "wiggling" that helps bust through uneven friction when running at slow speeds.

Cool! Thanks! I will now invest in another brick to power the trolley that runs above the TV, as it can now run quietly and doesn't have to slam into he bumpers to reverse! Awesome, I didn't want to buy a second one, if it was an imaginary fluke

I know what you're talking about.  I had an MTH Santa and Elf handcar which had to be set way too fast to keep it from stalling.  This meant slamming into the end-of-track bumper to reliably reverse giving the two guys whiplash.  In my case I swapped out the bumper lever switch that reverses the polarity to the DC motor and electronically reversed polarity triggered by magnets on the track - no more whiplash and medical bills for Santa!

The Fort Pitt Hi-Rail group had two modules, (8ft. total length), with a bump-n-go trolley.   Drove everyone nuts by the end of the day.   I spent some time to install a Dallee. Back-n-Forth system. Item #682.  Click on Instructions for details.  We probably needed a bit more length, (suggested 11 ft, (2) 2ft sensing sections, (1)each end, and 7 ft between), but it worked fine.  It was amazing to see this thing run for 5 or 6 hours. It took a little finess to get it running correctly on the short track. There are two adjustments. Sequence time, and Stop time. Requires Electronic reversing unit F/N/R/N and a lighted car/trolly.

Some pictures of the project.

In keeping with the quest for a quieter trolley (I like to run it above the TV), my investigation continues:

The IR controller has better voltage control, than the manual knob (makes sense, my PE express runs better on DCS varied output, than on the knob)

I'd like to try to run even slower. Is there a good PS that has a max out <18 - 21VAC? Could I use the Z1000 ACC output, for 1 trolley? I don't see an enercell offering, I do see cheap 12V 3A power supplies for laptops). Would that even work? Does the  IR lock on have a minimum input/output?

I started with reading Trolley Manual (ack)! No luck. The controller doesn't have a compatibility chart. The Troley doesn't list an AC controller with a lower output (the MRC II recommends the varable DC out)..

Some background

Starting voltage. Minimum output, measured across track using IR controller with Z1000  is 5VAC. This gives a smooth ride, plenty of power to reverse, without the whiplash momentum needed in DC or AC with the manual Z1000 knob. It still isn't as quiet as creeping on DC. Of course creeping on DC, doesn't give me the power or momentum to throw the reverse.I think I MIGHT get it to work on slightly less power and hence even less noise.

DC and AC varied with a knob, both start at higher voltages. This tells me simply running Brick -> Knob (to lower IR input V) > IR lockon won't help as the knob must chop the wave, in a way that would defeat the IR controller.

Note: I think the 5V minimum output , on the IR system is an MTH thing. It is talked about in DCS, so I'm guessing it has to do with the PS2 5V boards, so it shouldn't matter to a simple bump and go trolley.

aside:

Mike, that is cool, but would be overkill for me. A 6 ish ft shelf, of piece of Christmas Carpet Central

Picked up a used Atlas (now Williams) 80W transformer. AWESOME slow speed trolley and hand car control, with the bumpers still reversing the unit! I need to check it with a second meter, my Fluke is reading 1.8VAC, and I'm running an MTH trolley, slower that with the MTH IR conroller (min voltage 5VAC)