It's not even necessary to add much external stuff - many of the H bridge drivers used to drive the track have current sense pins - it just takes a little extra to read it witht he constant changing polarity of DCC. Han Tanner covers it in his latest booster design video on his IoTT channel.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
OvermodI have never quite understood why there isn't some little digital ammeter
the PowerCab has an option to display current (pg 59 of manual)
greg - Philadelphia & Reading / Reading
You could 'probably' run 3A or more through the electronics of a PowerCab system if you used some of the techniques from the computer-overclocking community -- better thermal contact between the components producing highest heat; better heat sinks or heat-sink cooling (including circulating water or oil, or even immersion in dielectric coolant), Peltier-effect coolers pumping heat to the sinks, etc.
Aside from this fairly definitively voiding any warranty that may be offered, there is no guarantee that operating in this range won't cause either progressive or catastrophic damage if unexpected insults occur. Randy and others of his expertise can probably get a good idea of how much could actually be 'gotten out of' the circuit as provided. My own advice is to keep the amperage and consequent EI power dissipation within recommended specs unless you are SURE what to do.
I have never quite understood why there isn't some little digital ammeter running off a Hall-effect sensor or whatever provided in these things. I see the whole circuit being peddled on some of these Chinese product websites for a couple of bucks, so how hard can it really be?
Yes and no. Not sure of the part number used, but the rate capacity of the components may indeed be 3 amps or more, but that's with proper heat sinking and ventilation. There is none in the Powercab, thus the statement from NCE that the PowerCab cannot sustain 3 amps of output without damage.
In that same article, it mentions that the protection is provided by the current limitation of the original power supply. If you use a higher capacity one, that much more current can flow through the PowerCab. Running one loco won't matter, but if there's a short - that's when you have problems. The original power supply limited current to 1.8 amsp, through a device which can handle 3 amps briefly - so plenty of headroom to not damage the PowerCab. 2.6 amps though, is a lot closer to 3 amps. The difference between continuous current and surge current is usually something more than .4 amps, so you are treading in dangerous waters using a 2.6 amp power supply to run the PowerCab.
With just one loco, which shouldn't be anywhere near the original power supply's 1.8 amps, chaning to a higher current power supply, all else being the same, would make no difference in the operation. If however, the voltage is different - then it would.
He is joking. lol
Plastics has nothing to do with it. It is all in electronics. Current protection but anything can be overdone if you try hard enough.
I have run my Power Cab quite often. Great controller.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
it's not the electronics but the plastic that limits how much current the PowerCab should handle
1) The PowerCab is NOT DESIGN TO RUN 3AMPS CONTINUOUSLY. The PowerCab can overheat deforming the plastic shell due to the high heat build up. You want the 3amps to ONLY be a peak current to handle high inrush current common found when working with lots of sound engines.
Personally, me just have a small switching module, only 1 engine at the time is operated, no problem there. If you have a "room layout" with multiple engines and operators, well, i should go for a booster from the get go.
On the NCEpowerCab trottle you can see how many Amp the engine is using, so of course you have to have some control over this.
Pete
That's getting awfully close to the limit of the PowerCab. It can;t really handle that level of current continuously and you are likely to damage the PowerCab in the event of a short. Unless you have somethign between the track and the PowerCab to limit the current. 2 amps is about the most they want - remember the power driver for the rails is crammed in the throttle and there's no real ventilation or any serious heat sinking of the booster component.
See: https://ncedcc.zendesk.com/hc/en-us/articles/203935645-Adding-more-power-capacity-to-the-Power-Cab
If you think you need more power, the Smart Booster is the way to go, plus then you can actually unplug and move around the room with the cab and the train won't stop.
I changed my cheap "china power adapter" following the NCEpowerCab, to a more exclusive one: Mean Well SCP-35-12 13.8v 2,6A. I mounted it in a empty PC power supply case and mounted a new switch.
Works greate for me, loco starts at 4-5 and go very slow up to 10 on the controller. (no more "jump starts")
I would suggest using a power supply designed & built by the manufacturer of the DCC system for that system.
You might be able to make something else work...BUT if you screw up well...there goes the system...more $$$ in the long run
Pass? Why? One of the few systems that no longer takes an AC input are the new Digitrax systems. The older DCS100 and DB150 could take AC or DC, and the NCE PH Pro box takes AC or DC.
It's system specific, you can't just say no way without knowing the syste, involved and what the specifications say.
A bigger concern is the current capacity. If hooking up to a 5 amp DCC booster, the power supply had better be able to supply at least 5 amps. If it can't, what happens is the supply voltage droops under load and then the DCC system starts acting goofy. That's why using an old power pack is NOT a good idea, it may work to test run a loco or two but soon you will reach that powerpack's capcity and the DCC system will act up due to too low an input voltage.
If the supply puts out significantly more current than the DCC syste, a fuse or fast acting circuit breaker should be installed between the power supply and DCC system to protect it
That said, neither option is really good, 12V is too low, and 16V is too high. 16V may be within the specifications of the DCC system, but any excess voltage above the track voltage setting is dissipated as heat. The more voltage 'wasted', the hotter things get, and the end result is the booster shuttng down before it reaches a full 5 amps, or whatever its rating is. 16VAC in is probably fine for a typical HO output voltage, generally 14.5-15 volts.
The output voltage of the PowerCab, and the Digitrax Zephyr systems, is a compromise, since they don't have track voltage adjustments. A little high for N/Z scale, a little low for HO, but acceptable for both.
Your best bet is to get the recommended power supply for your system and not muck around with makeshift DIY options, but if you understand the ratings and requirements, and what you have fits within the manufacturer's range of options, then it should work fine.
12 or 16 V AC ? Pass.
Henry
COB Potomac & Northern
Shenandoah Valley
Odd question. My NCE DCC system requires 120 AC and puts out 13.6 VAC to the track. The transformer puts out 13.9 VDC to the DCC system witch converts to 13.6 VAC to the track. I did all the measuments years ago with meters and a digital Scope.
You better know what you are doing.
I first powered my Lenz DCC system with an old toy train transformer. It worked, but it ran out of power with a couple of engines and a string of lighted passenger cars with old incandescent lighting.
Seriously, look for the right power supply for your system, buy it and use it. Makeshift power doesn't work as well in the long run. If you must, save it for structure lighting or powering a turntable.
It takes an iron man to play with a toy iron horse.
ndbprrWhich would be prefered?
It always helps to provide as much information as possible when asking advice.
What DCC system are you using?
Here is some information regarding Digitrax:
http://www.digitrax.com/tsd/KB352/powering-your-digitrax-command-control-railroad/
Maybe you will find it useful.
Thank you, Ed
And make sure your system wants AC!
Are you wanting to power a DCC system with it??? If so, I would strongly suggest spending the $$$ and purchasing the proper regulated wall transformer for your DCC system.
That said, 12v would be preferable to 16v. My NCE Power Cab is a 13.8v system.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Have an industrial transformer with taps for 12 or 16 volts AC. Which would be prefered? Thank you