DC: Multiple units vs amp draw

It's always been my experience that each time I add a locomotive to a mutiple unit train on a DC system, each locomotive loses power. I think it's because of the amps each additional locomotive draws. If I'm correct, is there anything I can do to increase amps besides buy a stronger/better power pack? I have 4 power packs. Could I increase amps by connecting multiple power packs to the same track? I definitely don't know enough about electricity to know if that's a possible/safe solution.

 

Since power packs have variable voltage output, there is no way to connect them to the same track. Your only real alternative is to purchase or built power packs with more current output.
Retired electrical engineer

 

Keith is correct to a point. The VA rating is the total output rating of model railroad power supplies. Most commerical model railroad power supplies have a 16 VAC accessory output as well as the track power output. The VA rating is the total output of both outputs combined. It is given as VA instead of wattage because the voltage on the two outputs is different, 16 VAC on one and 0-12 VDC on the other. And most all of the commerical model railroad power supplies are unfiltered DC track power, they usually call it Pulse power or something simular. That is because they have to be able to run the old cheap motors which you had to pulse or kick to get them to start moving. Such pulse power has not been needed for over thirty years in the hobby. On some power supplies you can turn it off. Your better power supplies are electronic and/or transistorized now a days. Get the highest rated VA output you can afford. a voltmeter and ampmeter are also very nice to have on your power supply.

 

Getting back to an old topic that's been on my back burner...

1. Is there any way to add an amp booster to an existing DC power pack that has a total output of 6VA? Probably not but I had to ask.
2. If not (assuming not), what is the most amps a DC power pack can supply to track?
3. Will each additional locomotive slow down all units because of amp draw... no matter what? (Again... DC) I believe the anwser is yes but I'm not 100% certain.

I will eventually make the "leap" to DCC but I would still like to weigh the "cost vs benefit" factor of suppling more amps to my current DC layout until I take the DCC plunge... which will be after we move. I'm not sure when or where we'll be moving but sooner or later we will be moving. That's all I'm waiting on... a reason to start a new layout... only with DCC the next time.

 

I would just go ahead and "make the leap." Installing the DCC power supply to the layout is simple--just hook up two wires and you are done. It can be a bit of a pain installing decoders in your motive power fleet depending upon how many locomotives you are operating and what brand/how old they are. Newer units are often plug-and-play, so you can have them set to go in about the time it takes to remove and replace the shell (on a diesel). Older units will require a bit of soldering, but even the toughest ones I encountered (mostly prehistoric Proto E8s) only took about an hour. That said, I did not install sound decoders, mostly because of cost, but that's a matter of choice. In either event, it took me about a month, converting one or two units per night and setting the CVs (you will learn about those when you buy the starter set. There is nothing to those). When it's done you will be much happier with your layout, and if you want to add power boosters you can do it.

GS

 

Perhaps this will prove illuminating.

GS

http://model-railroad-hobbyist.com/node/19588

 

I went for DCC for just the opposite reason. I wanted sound and then found out the benefit of multiple unit lashups and running longer trains. I then added a room onto the den to run longer trains a longer distance. I base all of this on the change over to DCC. so beware mktjames. The $ for the radio throttle and Zephyr and sound decoders was just the beginning but I would not go back to DC it is way to limiting on any kind of operations.

 

I went with NCE as well, and Jim is right. It's the best thing I ever did. My railroad requires 6-8 operators and with DC it was just a nightmare.

GS

 

So can anyone tell me how the output of a simple HO scale NCE Powercab system?
Volts?
Amps?
Thanks. - Brandon

 

I have a MRC Railpower 1300 power pack with an output of 7VA. How much more power would a MRC Railpower 1370 power pack with an output of 18VA produce? What I really want to know is, would I notice a considerable difference in power output? If so, about how much?

Another question about power packs...
I have 2 life-like power packs (they're blue). They are about 24 years old. Once in a while, I'll here a "click" or a "boing" (like a spring or something) and they stop working. After a rest period, they start working again. Are they just overheating and shutting off or what?

Thanks in advance for the replies.
- Brandon

 

Thanks for the explanation on the Lifelike power packs, Keith. That was my guess (overheating protection) but I wasn't sure. I get that V x A = VA = watts or that VA/V = A and that 18 VA = 2.57 x 7 VA. Wouldn't an 18VA power pack with an output of 12V and 1.5A provide 2.57 times as much locomotive performance as a 7VA power pack with an output of 12V and 0.583A?

-Brandon