The Preponderance of Power Packs Puzzle!

[Anonymous]

Somehow, through various train purchases in N scale and from people who have given me these things, I have ended up with three (3) like Bachmann Power Packs. Can (or shall I ask if it is wise) these units be used in tandem to boost the power going through the rails?

Is there anyway to accompli***his or is this a Tuesday afternoon fantasy flight of fancy?

[bman36]

Capt. C.,
Far as I know there is no way to wire these in tandem. My best advice is to give them away to another modeler who is in need. They don't have enough jam for what we run. I'm sure someone out there can always use a spare for their HO or N layout. Remember you reap what you sow, so giving is good. Hope that helps you. Later eh...Brian. [tup]

[Anonymous]

QUOTE: Originally posted by bman36

Capt. C.,
Far as I know there is no way to wire these in tandem. My best advice is to give them away to anther modeler who is in need. They don't have enough jam for what we run. I'm sure someone out there can always use a spare for their HO or N layout. Remember you reap what you sow, so giving is good. Hope that helps you. Later eh...Brian.

Thanks, pay it forward asthey say!

[RhB_HJ]

Yes, they can be wired to boost the voltage, if you like to live very dangerously!!!
And no, the power capacity will not increase while the voltage goes up.

[Anonymous]

Joe;

Contrary to what you have been told; I do not agree with these gentlemen, you can operate power supplies in parrallel (not tandem please). I am a qualified Electrical engineer (old qualifications though) and I sold transformers and power supplies for about twenty years; about twenty years ago, then I moved into high tech batteries prior to retirement.

For instace I have operated two LGB 1 amp power supplies inparrallel for years, to drive my big Mallet Loco with illuminated carriges.

If they are identical, just connect the outputs in parrallel, ie red to red and black to black but make sure the control knobs are centred or at least working in the same direction. What helps a lot, is if you connect one at the furthest distant part of your layout from your origonal one, this gives a much more even distribution of voltage over the entire layout. If you make a mistake the overloads should protect them, if not be careful!

If they are different, try to see if their specifications are similar, if so give it a try. If they are quite different, well send me through the details and I will give you an opinion, it will cost you a beer if and ever we meet inn the flesh.

Paralleling power supplies will provide you with the sum of their capacities and will not affect voltage, this is why they should be very similar. I cannot see any valid reason to connect them in series, ie red to black then use the red and black left over and even I wouldn't do it.

However before you do anything, look at the specifications for your loco and make sure it matches the specifactions of your power supply, if not see two paragraphs above


Regards


ian.

[RhB_HJ]

There was an instance in the 1950s in Switzerland on a display layout where two transformers were wired in parallel. By some fluke the one transformer got unplugged and someone touched the plug and received a fatal shock. (I guess 220 and a hefty power pack will do that)
This is not urban legend, I was only 9 years old when this happened, but I remember.
BTW we built our own transformers at school way back then, had to do the calculations for how many windings, what size wire etc. etc.
That was lots of fun, as was having a real "train nut" for a teacher. Much of this stuff was "applied math" at its very best. Wonder if one could do that today, eh?!?

[Anonymous]

Hi Captain,

Loose 'em. You can connect them but as soon as you start drawing power you'll probably cause a multi state blackout! Our gear draws too much, my 5amp was cutting out on Sunday with just 1 2-8-0 and some lighted stock - hot day though and the transformer was outside! Look in electrical supply mags for industrial transformers that are giving around 20v dc with 10amp power. They are quite cheap and you can them put a walk round throttle control in circuit.
Cheers,
Kim
[tup]

[bman36]

iandor,
Thanks for the info. As a kid I tried this and it all went up in smoke. Chances are something was wrong with one of the packs or I wired it wrong. Scared my mother and left my dad grinning. Still alive so this is good. Posted based on my experience...then again I was a crazy kid. Later eh...Brian.

[RhB_HJ]

The moral of the story is:

when working with voltages above 50V one does everything in the safest manner possible.
When the power is used in the garden one increases the vigilance by two steps because of the environment.

Of course this is just from an old fool who likes to live a little longer and takes the necessary precautions.

While I've been zapped in my previous profession (you work on electrically powered machinery, it can't be avoided) it was always minor zaps and I like to keep it that way.

[Anonymous]

Thanks for the posts. I will take the advise of reason and simply buy a power pack that is designed for my purposes.

Vic and others, can you give me a product number from the Aristo Craft items at Trainword1.com that will best serve my needs. I'm looking for a simple power pack that can run a considerable outdoor layout (I'm going to rig some battery powered lighting systems that I will use my basic electrical engineering skills to construct for strucutres.)

I am "in the dark" about what sort of thing that would really work. I am confused by some of the jargon I am running into as to transformers and power packs in regards to Large Scale. Please advise...

[Anonymous]

Well Joe here it is, you asked for it.

A transformer is an electro magnetic device that converts one voltage to another, its capacity to do this is mesured in VA. This is the same as watts including power factor.
So if you have a transformer of 100 VA with an input for you Americasns is 115V 60 Hz RMS, you merely divide the VA by the output voltge in this instance say 12 V which means 100VA/12v = 8 odd amps. And that is all you will get is AC out from AC in nothing else. In a perfect world it will draw 100VA / 115 V = 0.87A from the mains however transformers are very efficient devices but nothing is 100 % so this would probably be more like 1 Amp or a bit less.

Now a power supply is just that, a device that supplies power as and when required.In general in the old days, this meant a transformer to give you the voltage you want and a rectifier to convert it into DC, if required. But this is very basic and the variations on this theme are just astronomical.

You may consider in this modern day of solid state electronics that many things are required and many sources of power are available. I know a guy that runs a Gas Cromatograoph from natural gas using a generator power supply and a Heinkel engine that runs off natural gas to drive the generator. So as I have said the rquirements are endless.

Leaving MTS out of it the normal way a model train power supply works is a transformer from AC to DC, a rectifier to get to DC and a device called a Rheostat. This is essentially a variable resitance with a centre point at which the output voltage is zero.

If you want to go forward you turn the controller to toward the forward position, which will increase the voltage thereby causing your train to go faster and faster the further forward you turn it. Reverse is just the opposite.

Again the VA rating of your power supply will be the limiting factor as to how much equipment you can run off it. The amperage is only a resultant of the VA rating divided by the voltage.


Regards Ian etc.