Running both tracks off a single controller?

[velotrain]

Well - I'm finally operating.  The Portram that came with my start-set had gear issues, so it's on the way back to Plaza Japan; the Priority Express postage was about half the cost of a new one, but they said they'll reimburse me.  My feeling is that they should ask Kato for the money as punishment for shipping them an untested tram. 

 

Unless - is the drive so fragile that gears can get knocked out of place just from the shipping process?

 

However, I've just received a bargain Centram that I picked up on eBay, and the chassis for my Santram shell, so I've got two operational trams.  The black body of the Centram does a good job of camouflaging the chassis, as do the green-tinted windows on the Santram.  I'll admit that the lighting on the Kato tram is cute, but not having it isn't a deal-breaker for me.  I have noticed that you can't really appreciate the articulation on the wide UniTram curves.  Although, they're still fun to watch - even on a bare oval  ;-)

 

I'm wondering if anyone has ever jimmied the track power wires so both tracks are fed from a single controller?  I don't really see the need for a second one - for basic loop operation.  I would want to make sure that the polarity is reversed on the second track.

 

Speaking of controllers, does anyone know if Kato's is PWM?  The precise speed control with the Tomytec chassis is so amazing that I thought it had to be, but I've also heard that the Kato motor is a coreless pager type, which can be damaged by PWM.  The Tomytec motors look much more robust.  I've ordered a T-Gauge PWM controller, and suspect that would work with the Kato Portram - I presume it expects 3-4.5 volts?  Anyone know what range the Kato controller puts out? 

 

Charles

[cteno4]

Charles,

 

The kato portram uses a built in voltage regulation to from the usual 0-12v power pack voltage down to like 0-3v for the tiny motors. Not sure if the t gauge controller may have enough power for n scale trams, but it might.

 

Easy to just snip your power leads and flip one to run the two tracks from one pack.

 

The kato portram mechs are really tiny and fragile. The tomytec mechs are very robust, but very big, so always a trade off.

 

Jeff

[velotrain]

Thanks for the info Jeff -

 

Besides the voltage regulation, I wondered if there was other electronic manipulation going on, as the unit starts at such a slow speed and can really crawl along extremely smoothly.  Given the general crudeness of pager-type motors (far from a Faulhaber), I had to suspect that there might be something else at play.   I'm also looking into the Heisswolf controller, which is highly regarded, but somewhat difficult to obtain - unless you're in Germany.  I have some of the Busch HOf Feldbahn equipment, and it was recommended for that (Busch default is two AA batteries with no regulation), as well as the T gauge.  The Busch magnets are so strong that I tried running the engine on a vertical loop tonight, and it had no problem.  I trust that the Portram on-board regulator doesn't engage unless it needs to.

 

The lights went on in my Portram and I could hear the motor revving, but it wasn't moving.  Poking around the net I read that the gearing is the fragile part, and based on the evidence that seemed to be the problem, with a disconnect at some point in the drive train.  I would have thought they were tested before leaving the factory, so wondered if shipping could have dislodged something.  I can appreciate that the Tomytec mech in a Kato shell would be ugly, but I have no issues with it in the Tomytec shells that I have so far.

 

I might set up some mini connectors on the power leads, so I can quickly swap out when I want to.

 

Charles

[kvp]

The kato pack is just regulated half waves at the double of the line frequency. 12V is at the start of the red mark. Top power is around 16V. Tomix is true pwm with some hf dc constant lighting thrown in for some controllers. The kato portram has a voltage regulator somewhere. It could be as crude as an analog voltage divider or as complex as a dcc chip running in analog conversion mode with a low voltage pwm drive.

[velotrain]

12V is at the start of the red mark. Top power is around 16V.

 

I don't understand this.  They list it at 12V - why would they even allow the possibility for people to apply a higher voltage - and maybe cook a motor?

[brill27mcb]

That's why it's the Red Zone.

 

Rich K.

[velotrain]

That's why it's the Red Zone.

 

Rich K.

 

I got that, but I'm asking why even have it.

[kvp]

This way you can use a single controller for N (max. 12V) and H0 (max. 16V). Kato makes both.

[cteno4]

Charles,

 

Most n gauge stuff Is flying off the tracks near the red zone.

 

The kato portam motors are not cheap pager motors. Also t scale motors have gone thru 6 generations now. The latest is a custom design and build motor and what drove the train prices up on them as they are not cheap. But they give much better performance than the earlier motors. Their new pw controller helps a lot as well.

 

Not sure what the voltage regulation circuit on the kato portram is. KVP you should look at ffiskiv's gallery you can see some of the pc board in it

 

http://www.jnsforum.com/community/gallery/album/34-kato-portram-disassembly-pictures/

 

Cheers

 

Jeff

[velotrain]

Thanks for the info Jeff.

 

>  Most n gauge stuff Is flying off the tracks near the red zone.

 

Wouldn't that make the Shinkansen guys happy?  ;-)

 

 

I hadn't realized that very small trains using "pager-type" motors had become so sophisticated.

 

Do you have any sense of how the T-gauge MPW controller compares to the Heisswolf?

 

Charles

[bill937ca]

Charles,

 

The kato portram uses a built in voltage regulation to from the usual 0-12v power pack voltage down to like 0-3v for the tiny motors. Not sure if the t gauge controller may have enough power for n scale trams, but it might.

 

The kato portram mechs are really tiny and fragile. The tomytec mechs are very robust, but very big, so always a trade off.

 

Jeff

 

Some photos of the Portram mechanisms.  A dis-assembly thread with photos.

 

http://s305.photobucket.com/user/raylue/media/RailModel/KATO%20PORTRAM%20TLR/P9.jpg.html

 

http://s305.photobucket.com/user/raylue/library/RailModel/KATO%20PORTRAM%20TLR?sort=3&page=1

Edited July 25, 2014 by bill937ca

[cteno4]

Thanks for the info Jeff.

 

>  Most n gauge stuff Is flying off the tracks near the red zone.

 

Wouldn't that make the Shinkansen guys happy?  ;-)

Well we try not to do that. Actually we try to run them at the prototypical scale speeds not maglev speeds! Use to have a speedometer to keep us very kosher, but it broke after a few years and now we just count alligators on laps to get in the right ballpark.

 

 

I hadn't realized that very small trains using "pager-type" motors had become so sophisticated.

 

Do you have any sense of how the T-gauge MPW controller compares to the Heisswolf?

 

Charles

Only played with the new t gauge controller once and was much nicer than the old one. The us distributor trainaidsa is local here so I have coffee with him now and then. Never played with a Heisswolf.

 

Jeff

[brill27mcb]

One issue with running two tracks from one controller is having cars that run at comparable speeds at a given voltage.  When we operate a large tram layout with EasyTrolley design, we add a control box or two that I have built with separate on/off/reverse toggle switches for each track to help keep cars spaced apart. In addition, we mimic what roller-skating rinks used to do. Instead of announcing "Ladies only" or "Couples only," we have session times for "Tomytec only" (they run very fast), "Bachmann only," "Modemo only" and so on, so that all cars out on the line share compatible operating speeds at the same controller setting.

 

Rich K.

[velotrain]

Rich -  This would only be for casual running at home, where I wouldn't care to what extent the cars are in "synch" or not.

 

You mention roller skating, but I was thinking it could be more like team ice skating, where two cars start on opposite sides - heading in the same direction, then try to close the gap on each other ;-)

 

Charles

[kvp]

Actually, there are 101 ways to make simple controllers from a rotary switch with a diode ladder to an LM317 (used by Lego, Maerklin and Trix) or a power diode (Kato) to the more complex PWM circuits (both 555 ic or microcontroller based, used by Tomix and most DCC chips).

 

 

I would suggest the LM317:

Input should be around 12V DC, voltage control is through a potmeter at Rl, add a DPTT switch for forward/stop/reverse. Cost should be around a few dollars. The good side is that a single 12V wall adapter could power a bunch of these, so it's possible to add dedicated speed control to every block on a layout. Extend the circuit with protection diodes, filter caps and led lights according to personal taste and budget.

[HantuBlauLOL]

I run my double tracked layout with one tomix N1 controller fine, the train's speed are same whether im running in a single or two tracked layout.

 

The only problem is the controller heated twice faster than when i used it on a single track layout, so i dont think that you can run your trains for more than a hour.