I wired up a 3800 mAh 3s LiFe battery to a 5.5mm/2.1mm plug (center positive) and plugged it into the AC adapter socket on my Rokuhan RC-02 controller. This is working perfectly and the average operating voltage of the LiFe battery is 9.9v. Peak voltage off the charger is about 10.5 and by 9.0v it is time to charge so in practice it will be necessary to monitor the voltage or provide an auto shut off or alarm to prevent over discharge and damage to the battery. I was hoping to use the same battery and plug for my BlueLine Snail Speed controller but it is not working. It could be the Snail Speed controller AC power supply is center negative. It could be that the plug I think is 5.5/2.1 is not, I just measured it with a caliper. Or it could be the Snail doesn't like my battery. The Snail does shut off when I plug in and turn back on when I disconnect the battery. Thanks for any help here. If anyone has a Snail wall wart could you confirm the plug polarity? Or could anyone tell me if the Rokuhan and Snail AC adapters are interchangeable?
LOL Well, I found out the Rokuhan wall wart was center positive by Googling pictures of it. I couldn't find pics of the Medvend unit. Then (after posting my question of course) I went back to the Z Track Center website and had another look. The part number of the Snail Speed wall wart is: 9V1A-21-NEG-WALL Now the light comes on, I mean the light that cartoonists put above a characters head when they get an idea, mine is kind of dim! Anyway the "NEG" part caught my attention. I Googled that, it is indeed a non standard center NEG plug type. I am lucky that I did not damage my controller. I wired up a polarity reverser plug and the Snail Speed controller is happily pushing my train around the track via the big LiFe pack and the same plug wired center negative. I intend to use a large battery like this in my "coffee table layout". I love that Z scale can be powered with relatively small rechargeable batteries and I think there could be a market for these among us. I was burning through AAA and 9v batteries pretty quickly. I'll try to post a pic soon.
FYI the capacity of a 9v battery is 310mAh and the capacity of a AAA battery is 1000mAh. The 3s LiFe battery pictured has a useful capacity of 3800mAh.
I got the Rokuhan AC power supply and was surprised to see that it is 12v 1A and actually can put 12.1v to the track. I checked that with my volt meter. The good news is the Rokuhan turnout that has been giving me trouble on 9.9 battery volts (or less) seems to work 100% of the time on 12.1v, the bad news is the older Marklin 5 pole locos are just as likely to trip the Rokuhan controller over current protection with a 12v wall wart as they are with a 9.9v LiFe battery. So the Rokuhan over current protection feature is not affected by the power source or input voltage. If there is any drag on the loco at all it will shut down. Often I have had issues with the protection feature repeatedly shutting off the Rokuhan controller and have been able to plug in the Snail Speed controller and get the locos moving again. And I must admit that the little Snail Speed controller is generally able to start the 5 pole Marklin's up at a slow speed where the Rokuhan controller needs more "throttle" before the train gets going. I have been running two 5 pole trains at once quite often while parking one or the other and of course that is why the sensitivity of the Rokuhan protection feature is more of a problem. Running older Marklin 5 pole locos on my layout and sometimes in tandem the most reliable operation is the Snail Speed controller on a big 9.9v battery or its 9v wall wart for the trains and the Rokuhan controller on its 12v AC power supply for the turnout switches. In any event I would not really want to run the Marklin engines without easy access. This all changes with my newer "modern" Rokuhan loco. Either controller can do the job with the lights on at stop being a very desirable feature with the Rokuhan controller. Next I will try running the Rokuhan controller on a 3s LiPo battery. They are rated at 11.1v and come off the charger at right around 12v so hopefully the turnout will be reliable at that voltage. A battery powered track has always been the goal. Before any of you asks why I am so enamored with the Marklin locos I will say that I just love the look of their steam engines. And they won't be digitized anytime soon (?) so I am just trying to get the layout as reliable as possible with DC control on battery power.
How are you measuring output on the Rokuhan? Its a complex signal and needs oscillocope ... otherwise you're looking at the "background" signal used to power the constant lighting (12v).
With a standard voltmeter. The wall wart has 12v 1A printed on it and at the barrel plug I measured 12.1v. After plugging in the controller across the tracks with the RC-02 wide open I also measured 12.1v (no train on track). But there may be more to it than I realize. I figured the higher voltage was helping the turnout to operate. But I did not measure the voltage delivered to the turnout by the C002.
A few thoughts.... Regarding meters, some will measure the track voltage correctly, some not. I have 2 meters that always reads about 12VDC, one that matches my oscilloscope readings and one that just can't make up it's mind. If you set the throttle to minimum and measure a track voltage other than about 300mV, you should be suspicious of your meter. The throttle basically passes whatever it's input voltage. With batteries or the now "terminated" A011 wall wart, the output is 12V. With the new A028 wall wart it's 10V. Output voltage can vary by as much as 10%. As far as driving the turnouts, the Rokuhan switch is a capacitive discharge design and only outputs a pulse, so you need an oscilloscope to see the output. Personally, I've been less than satisfied powering the turnout controls through the RC02. I've taken to driving them through the separate power input on the switches. There's a number of things to consider with the Märklin loco tripping the RC02. If I read your posts correctly it sounds like the engine most runs alone but generally trips out with a load. First, you should try running the throttle at 10VDC. The 3 and 5-motored Märklin I have draw significantly more current at higher voltages, possibly making the trip issue worst. It seems that the locomotive operates close to the limit of the throttle. It might be worth running the loco without it's lights to reduce it's power draw. Not a solution but it does tell you how close to the limit it's running. Mark
Based on what you say about the oscilloscope voltage it then sounds safe to power the Rokuhan RC-02 controller with a 3s LiPo battery putting out a peak of 12v (and averaging below that, finishing its useful charge at 11.1v), as that is what the Rokuhan A028 puts out. And run my all trains (not just Rokuhan ones) without fear of over voltage. Thus coming closest to the Rokuhan operating spec for the turnouts. I do not know if it is is safe to power the Snail Speed controller with the same 12v battery. Its manual clearly states not to use an AC adapter putting out greater than 9v and that is what the Blue Line Snail Speed AC adapter is rated at. But I have run mine quite a bit on 10.2v on battery power. And the Snail Speed operates on a different principle than the Rokuhan. So: Rokuhan controller with its 12v AC adapter, or hopefully 12v battery, safe for trains and operates Rokuhan turnouts most reliably. The Rokuhan controller at lower battery voltage begins to have trouble operating its turnouts. Snail Speed controller, AC adapter 9v, tested OK with up to a 10.2v battery, OK for trains, but not 100% reliable power for Rokuhan turnouts. May or may not be safe with a 12v AC adapter or battery as that exceeds manufacturers specs. The goal is the most reliable and realistic operation of the layout on a single battery. I may burn something up playing with this stuff, or I may realize that trains and turnouts are not 100% reliable, LOL. At this point I am pretty sure a completely covered "coffee table" layout is not very realistic when actually running trains. Sure, it can look amazing as a glass covered railroad scene, and I could probably get away with running it covered for a few minutes, but for really enjoying it and swapping trains out and running the turnouts and bumper tracks, for safety, etc. easy track access is a necessity. I'm finding out running model trains are more "hands on" and maybe even "more fun" than I originally imagined. Happy Easter everyone!
Running a märklin (or other Z loco) should produce the Adam's Family Lionel effect. WAY TOO FAST. Most *all* of our locomotives run quite well a ~6 volts with a nominal ~9 volts max rating. You might notice that the higher the voltage the train likely does not go proportionally faster. This means that the overall motor perfomance (brushes, etc), truck friction, etc) and other factors prevent the loco to run as fast you might expect. You can usually measure that by placing 2 meters with one measuring current (in series to/from the track) and voltage at the controller. The märklin motors have quite a bit of current variation, as does MTL's F7's but also AZL too. The difference with the Rokuhan and AZL is modern 'Can' or Coreless motors which are far more efficient and draw *much* less current than märklin and MTL's F7's.
Thanks Mark and Jeff. BTW, my last post came after reading what Frank said and appeared before Mark's post, but I read Mark's post after my last post. Anywhooo, the Rokuhan A028 packaging says 10V but the wall wart in the package is labelled as 12V, and it measures at 12V. The RC-02 actually has "Input DC 10V" printed on it, so go figure... At min throttle the Rokuhan controller puts 0V to the track, then when switched to FWD or REV but with the throttle at min I measure 65mV via my 10V LiFe battery and 95mV via my A028 AC power supply. This is proven out by m y little Rokuhan Z Shorty loco which I got thinking it would be useful for testing stuff. With the Snail Speed controller it doesn't move at idle, with the RC-02 on 10V battery it moves very slowly at idle, and with the 12V A028 it moves faster but still slowly. Thanks for your idea of powering the Rokuhan turnout switches directly Mark, I will try that. The pulse you speak of may have trouble powering the pair of turnouts as I have them on a Y. But again they generally work, just not 100% on lower power. And Jeff I have been running my trains very slowly. I think I'm pretty good at finding scale speeds and I hate seeing them racing around the track. Probably another part of the problem. I really need to reiterate that I am new at all this and finding that I have trouble differentiating between controller issues and loco issues. Today I spent some quality time cleaning a set of "new" loco's. Marklin 40 years anniversary set 81972. All 5 pole motors. The set has three engines: The BR89 060 runs amazing! It can crawl around at truly snail speed smoothly for as long as you like. I left it alone. The BR003 462 was having little micro stops. I cleaned and lubed it without solving the problem but when I removed the brushes and after I cleaned them and the commutator it is now running perfectly. I am thrilled about that fix. The V60 060 was also having micro stops which I couldn't fix even after cleaning the brushes, I even swapped the brushes L to R with no improvement. Then I took a higher magnification look and realized one of the brushes is broken, instead of a curve it is a point, chisel tip brushes, no good! So I need to replace those. My point is these loco issues are definitely part of the reason I am doing all this detective work with controllers. Misplaced problems. I just assumed a "new" set of Marklin locos would run well out of the box. And as with my "Tiger" loco which I wrote about in another thread I am finding this is not necessarily the case.
Regarding the Rokuhan turnouts. using the 12VDC to the C002 I've had no problems switching two with the Y cable. As I recall, Garth posted a while back that the limit is 4. Something to consider for powering the snail and Rokuhan throttles from you battery, is to build a couple of regulators to power them. It takes just a couple of common components: some capacitors and an LM7809 (9v) or LM7810 (10V) regulator. Schematics as well as kits are available on line. Mark
Thanks Mark, I'll look into that. I use lots of step down regulators in my RC models, they look complicated to me, but most of them can handle a large range of input voltage and provide programmable output voltage. I have thought of using one of those. Interesting point about the lights as the loco that gives me the most trouble with the RC-02 over voltage protection kicking in has two lights, one up front and one for the drivers cab, it looks cool though!
