Choosing a DC throttle

[CaptOblivious]

Everyone's got an opinion. Well, I don't know that I do, but I know others here do. It'd be interesting to get some considered feedback on a good throttle choice. I know there's at least one member who's probably currently asking himself this question…

So, to get the ball rolling, I found this page enormously interesting:
http://www.scottpages.net/ReviewOfControllers.html

[brill27mcb]

Everyone's got an opinion. Well, I don't know that I do, but I know others here do. It'd be interesting to get some considered feedback on a good throttle choice. I know there's at least one member who's probably currently asking himself this question…

So, to get the ball rolling, I found this page enormously interesting:
http://www.scottpages.net/ReviewOfControllers.html

There are several issues to be aware of with pulse-based DC throttles, whether they are width-modulated or not. One is the maximum voltage of the pulse. It should not exceed the nominal voltage of the throttle, such as 12 volts. Otherwise the high spikes of voltage can damage (zap) the insulation of the armature windings. Apparently one was the old Troller brand from the U.S. which would burn out early can motors like the Sagami. Q-Car Company, a power truck supplier for O-scale trolleys, still has a warning about "pulse throttles" many decades later for this reason. The other issue, which the article linked above does not discuss either, is the frequency (hertz) of the pulses. Old open-frame motors were oblivious to pulses because of their slow magnetic field reaction times. Newer, smaller-amperage motors like can motors are more sensitive. Higher-frequency pulses cause less of an issue, though they might not improve slow-speed operations as much. The most sensitive to pulses are the coreless armature motors.

Rich K.

[David]

I'm not really a fan of throttles that look like they where made in 1970 (or worse, look like toys made in 1970). To me they don't look very attractive, and I just can't shake the vibe I'm going to get electrocuted (they give the impression, some for good reason, that a lot of amps are going through some old iron coil waiting to short).

If it's going to be DC I'd either go with the old faithful Kato blue controller (nice, smooth, worry free), an American momentum controller from the MRC series, or a 'cab' style simulator controller like the $250 Tomix one (I have the TomyTec one which is nice, but when operated in simulation mode it seems to dislike the higher stall speed of most proper model trains and just gives up after 2 seconds).

[KenS]

Interesting website, and it probably explains why Kato is using the "closely spaced pulses" approach, as it would create less motor heating.

I don't really have a preference in DC power packs, as I only use them now for running new trains and trains I haven't converted to DCC. But I think it does makes sense to prefer a power pack with a maximum output voltage appropriate to the scale in use (and the web page Don linked makes a strong case why pulsed power on a higher-voltage pack would be a problem).  For that reason, I like the Kato power packs (Tomix is a similar design, but I don't have experience with them).

But I think I'm going to retire both my MRC power packs, as even the one that doesn't claim to output pulsed power is doing just that, and both are using the "widely spaced big spikes" approach, and it appears that at 12V RMS (about medium throttle) the spikes are up to 16V high, although reading absolute voltage off my oscilloscope is hard, so I may be misreading it.

[KenS]

Over on the MP15 thread Howard noted that MRCs "Tech 4" throttles output 23 volts (except for the 200, which is rated for 16V max). And the manual on MRCs site agrees.  I think that's a scary amount of voltage for N-Scale, particularly with pulsed power.  Yet many people seem to use these with N-scale trains.

Anyone have long-term experience, good or bad, with the Tech 4 220/260/280 units?

[inobu]

KenS,

I'm glad you are posting the warnings too. A noobie can get into some real trouble with a power unit like that. No one expects to have a fire extinguisher around a "little
toy train set" but pack that much power and as posted on the unit it's not a toy any longer.

Inobu 

[keitaro]

I use the gauge master deluxe 2 track controller with simulation.

Very good does 12v dc @ 1amp per track and has 2 dc 12v for switchest and another 2 16v for lights etc. Very smooth train but really hard to get used to the simulator.

I type this on my iPhone and voltages may vary slightly but that's from memory.

[KenS]

I was curious about the effect of pulse power on an n-scale loco, and while I was in my LHS today I noticed they had an MRC220. Slightly lighter in wallet, I went home and did some experimenting (photos below). Yeah, I'm easily distracted. I was supposed to be working on the layout tonight (I actually did get some painting in while the tests were running).

For testing, I put the test locomotive on a "rolling road" (set of bearings that allow it to spin its wheels without moving) hooked up to my multimeter and oscilloscope (and also the RRampMeter, although it only works if the voltage is above 7V).

While the 220 does put out fairly high voltage, driving an N-scale loco (a modern Proto 1000 with a 5-pole motor I keep around for potentially destructive tests like this), it was only 19.2V at maximum. With the throttle at the 80% mark, it was putting 16V into the loco, and at 62% 12V. The minimum setting that would move the loco was around 15%.  That means that for N-scale only about half the range is useful.

The other part I was concerned about was the effect of pulse power, and how it would heat the motor.  I ran the locomotive on a Kato pack at 5V and 10V for a half-hour each, checking motor temperature every few minutes to make sure it stabilized, to create a baseline, then did the same with the 220.  With the Kato, 5V was the lowest that would cause the motor to run reliably (I tried 3.7V and 4.3V, and while both worked briefly the motor soon stalled). With the 220, on the other hand, low-speed ran as low as 1.7V DC (actual voltage was probably slightly different as the AC voltage appeared to be 2.4V and the pulsed waveform was confusing all of my meters). But the actual rotational speed of the motor seemed about the same at 1.7V pulsed on the 220 as it had at 4.3V on the Kato (somewhere around 100rpm). Low-speed operation might be more reliable on the 220, but I can't tell from these tests (I'll try some test-track running later in the week).

The other thing I noted was that the MRC is doing pulsed power right, with pulses about 8V high at low throttle settings (gradually widening as the throttle is advanced), which get lower (I suspect the low value between pulses is actually rising, but my scope doesn't show that well) until the pulses disappear at about 9.8V DC. That's what you want, as pulses are only useful at low speed, and potentially damaging at higher voltages.

I checked motor temperature during the tests with a hand-held remote IR thermometer. Temperature wise, there's no issue here either.  The Kato 10V test got the motor up to 89.8F (32.1C) in a room at 63F (17.2C). The 5V test only got up to 80F (26.7C). The MRC peaked at 86.8F (30.4C) in the middle of the 10V test, but dropped back to 84.5F (29.2C) by the end. And the low-speed tests, rather than getting hotter, ran quite cool; the worst was the 5V test, which got to 83.6F (28.7C), but the lower-speed tests ran cooler (I didn't measure exactly as the temperature was falling from the earlier tests, so I didn't run the full 30 minutes, but the 1.7V test got down to 74.4F (23.6C) before I gave up.

I was running the locomotive with the body shell off, so the motor was getting more airflow than it would normally, and thus was running cooler. But since the temperatures between the Kato and the MCR were so close, they'd both likely be the same amount warmer with the body on.

So, while the peak voltage is a bit too high for comfort, careful use of the throttle will avoid that problem.  And while it runs a bit hotter than the Kato did at 5V, the difference is pretty small.  If you really like the momentum and low-speed characteristics of this throttle, it should be safe to use as long as you keep the knob below the 62.5% mark.

[Howard]

Over on the MP15 thread Howard noted that MRCs "Tech 4" throttles output 23 volts (except for the 200, which is rated for 16V max). And the manual on MRCs site agrees.  I think that's a scary amount of voltage for N-Scale, particularly with pulsed power.  Yet many people seem to use these with N-scale trains.

Anyone have long-term experience, good or bad, with the Tech 4 220/260/280 units?

Well, I can't comment on the Tech 4 powerpacks, since I don't have any. I do own two identical MRC Tech 2 2500 throttles, I bought both around 1997 I think. I don't remember the exact year, but it was probably between 1995 and 1998. I have used them ever since. Too be honest, I normally leave the momentum switch turned off, I almost never have it turned on. No particular reason for leaving it off, it's probably just habit.

Anyway, during these past 15 years, I can operated many different brands of HO and N scale locomotives, and I never experienced any problems. Perhaps because I rarely operate my equipment at over 12 volts, or turn on the momentum, only on occasion. These throttles are rated at 20 volts max.

I do agree, I think the 23 volts from the Tech 4 packs are way too much voltage for N scale, even too much for HO scale in my opinion. That high voltage is more suitable for G scale.

[Hobby Dreamer]

Hi
Could someone recommend a good Tomix one as the catalog is in Japanese.

Thx

[bill937ca]

From Tomix I would suggest the 5506.  This is their basic DC controller.  It has outlets for stack-able control boxes which control your switches electrically. There is a cheaper 5504 but it is more limited in operating switches and other accessories.  Each of these controllers has single power control, but you can run trains on two tracks by using 5812 DC divergence cord and two 5534 DC feeders.  I do this all the time. Incidentally, the side of track that you plug the 5534 DC feeder effects the polarity.

In addition to a 5502 (an earlier version of the 5506) I have Tomix 5512 cab controller. This is large, heavy controller with separate handles for power control and braking. It has direction and power controls for two separate tracks (which also require two separate sets of power cords) These units are large, heavy and very expensive to ship.  I find exact braking harder with this unit,  The reaction time  from brakes applied to actual stop in N scale distance is enormous with this unit. I never could control trams with this unit to my satisfaction.  It seemed so exciting at the beginning!

I don't have the Tomix  5514, 5515, 5516 wireless controller, although it looks tempting. There also is an automatic control unit the Tomix 5563 for which you need sensors and a separate power controller.  Up to nine different patterns can be run such as back and forth, oval with alternating trains or oval with random stops.

I do not leave my Tomix controllers plugged in when not in use.  These are designed for 100V Japanese mains rather than our 110/120V mains.  I use a step down converter for Japanese voltage just to be safe. Some suppliers say you can run them directly off North American mains, but I choose to be cautious with the voltage difference.

[The_Ghan]

I still have my old "Hammant & Morgan" Powermaster.  I'll never part with it as I've had it for nearly 40 years.

Cheers

The_Ghan

[David]

I still have my old "Hammant & Morgan" Powermaster.  I'll never part with it as I've had it for nearly 40 years.

Thanks to the way your hands clench onto whatever you are holding when you are electrocuted, they will have to literally pry it from your cold dead hands. 

[brill27mcb]

For Tomix, I would second Bill's recommendation of the 5506 N-1001-CL. It's not really their "basic" controller, it's the mainstay workhorse of their offerings. The others are either less capable or add bells and whistles. More info:

http://www.trainweb.org/tomix/control/TomixControlSystems.htm

Rich K.

[David]

The others are either less capable or add bells and whistles.

Don't forget the tunnel echo and flange squeal. It adds those too.

[Hobby Dreamer]

Thanks Bill, for taking the time to explain the controller!

Where did you buy  the step down converter, as that sounds like a good idea.  I have a MRC unit from about 10 years ago, and although I loved the momentum and braking features it seems best to use a Tomix or Kato controller especially for the Kato Portams.

Thanks Rich, that's a lot of info on your site!!


Cheers
Rick

[rpierce000]

I ran a four track demo layout at a train show in OR last month with a pair of MRC tech 4 280s (dual throttles). We ran a Kato M250 sixteen car consist on one track for four hours straight at 70-100% (Usually at 70, more when the kids drove). At the end of that the engine was barely warm to the touch. We also ran Tomix 0,100 and 300 shinkansens, some Kato EF and ED series pulling passenger or freight drags and a Tomix OER 7000. No problems with any of them for temperature or speed consistency.

Two caveats:

1) We were running on the flat. These were Unitrack V11 and 14 nested loops, nothing fancy.
2) These trains had all been cleaned and lightly oiled for the show

[bill937ca]

Thanks Bill, for taking the time to explain the controller!

I got mine from Sam Stores.  They ship UPS to Canada which can be expensive. I've got the small transformer and a larger one for my 5512.

http://www.samstores.com/Store.asp?CtgID=359

[brill27mcb]

Mine also came from Sam Stores, and is similar to the little SM-100J. I have successfully run two Tomix power packs (5502 N-1000-CL and 5040/5015 DU-1 Transistor unit) off of it at the same time. In North America you can just use the old-fashioned 2-prong extension cords and 3-outlet blocks -- the ones where the two prongs are the same size. Be aware that if the description doesn't explicitly say UL-approved, it probably is not. Bill and I both unplug our converters and power packs when not is use, just as a precautionary good habit.

Rich K.

[scott]

I was unaware of the depth of my ignorance about all this.

We use three MRC Tech 4 260s with momentum (god i love techno-man-talk in the morning), and haven't seen any problems yet. Of course, our layout is terminally under construction, so we don't get as much running time.

[KenS]

If you don't send the trains flying around at warp speed, you're probably not running with an excessive voltage, in which case even a 19 volt MRC throttle shouldn't be a problem.  It's just that you lose some of the range on the knob.

[scott]

I only tend to use the higher end to get the train moving, and then very quickly back down.

[Mudkip Orange]

Anyone have long-term experience, good or bad, with the Tech 4 220/260/280 units?

I use MRC controllers for the HO, but have avoided using them on any of my Japanese N mainly for the reasons Rich posted.

From the dawn of time I have run my Japanese N with a couple of ye olde craptastic Bachmann 6607s. These output a fairly smooth wave so motor heating isn't an issue. The big downside to this controller is there are only about 4 or 5 speed settings, it's not continuously variable. Replacing it with a couple of Kato "blue boxes" has always been on the to-do list, but when you're choosing between a couple power packs or a new train...

[lordwinslow2]

I ran a four track demo layout at a train show in OR last month with a pair of MRC tech 4 280s (dual throttles). We ran a Kato M250 sixteen car consist on one track for four hours straight at 70-100% (Usually at 70, more when the kids drove). At the end of that the engine was barely warm to the touch. We also ran Tomix 0,100 and 300 shinkansens, some Kato EF and ED series pulling passenger or freight drags and a Tomix OER 7000. No problems with any of them for temperature or speed consistency.

Two caveats:

1) We were running on the flat. These were Unitrack V11 and 14 nested loops, nothing fancy.
2) These trains had all been cleaned and lightly oiled for the show

I have a MRC Tech4 280 Dual too, with the output of both controllers around 15VDC, I am not too worried.  I am mostly using it for my Tomix Wide Tram track for trams and such, I got a double loop and it runs well.  To run the ACC (Switches and such) from Tomix, I will get one of those power converter units, I think the Tomix 5500.   Since I am just running around 30-35% of throttle so I get realistic movement of the trams it works well for me.  I would also use it on a larger layout as well and I am thinking of getting another one to replace the Kato Units I have now, since I am not planning on going DCC for a while.  

Winslow