Power pack

Discussion in 'FAQs' started by CPRail, Jun 20, 2004.

  1. CPRail

    CPRail Member

    hi everyone, is there anyway i can increase the amps that my powerpacks puts out? right now my powerpack is quiting on me after usin it for 5 minutes powering 3 athearn locos wit out any cars :curse: ( nothin wrong wit locos there bascially brand new, and have been tested at my local club!!). it is a tech 2 1400 made by MRC. i wuz thinkin about making a home made amp/booster 2 try and put out more amps. i want 2 use this power pack for my mainline run which is about 100' long (not yet completed), but it will be cut up into several smaller blocks. Anybody have any ideas how i can solve this problem?

  2. RailRon

    RailRon Active Member

    Hi Joel,

    by googling around I found out that your MRC 1400 power pack has a power output of about 14 VA. (VA or Watt is the physical unit for measuring power. You get the power by multiplying Volt times Ampere)

    This means, that with an output voltage of 12 Volts (normal for H0) you can only draw a bit more current than 1 Ampere. If you run 3 locos and every one of them draws only a current of 0.5 Ampere, you already have an overload: 1.5 Ampere x 12 Volt = 18 VA! :( ) The transformer overheats - and pop goes the circuit protector... :mad: And if you add additional loads at the AC terminal (signal lamps, turnout motors...) it gets even worse. :curse:

    Such is physics - you simply can't get more power out of of a transformer than it is designed for. Therefore there is no such thing like an Amp booster! :( To get more power from your pack, you had to rewind the whole transformer. BUT: Hands off from such an enterprise! This could be VERY dangerous - you don't want to be electrocuted, would you?

    Sorry to say, but it looks like your power pack was simply not powerful enough to run your whole layout. So most probably you'll have to swallow the bitter pill and hunt for a more powerful pack. I'd recommend something with a 30 to 50 Watt power rating. In the long run you are better off when you pay a bit more, but then you have ample power to run all your lokeys! :thumb:

  3. Fred_M

    Fred_M Guest

    Back in the 70's we built a dc powerbooster using a 16volt 10 amp transformer and used the old powerpack's variable output to supply the base power to some power transistors (6 from memory) which would then control the output of the 10 amp power pack. It was hard to adjust, keep working, and expensive to build. I would say you would be time and money ahead to buy a bigger MRC pack and use the little one for the yards or powering the buildings. We got the plans from an early 70's Model Railroader mag. Seems we spent over $120 building it back then. The heatsink for the transistors was a 1/8 sheet of Al about 12 X 18 inches and got really hot. Fred
  4. Pitchwife

    Pitchwife Dreamer

    If you break up your track electricly so that you have several power blocks and only use one controller per train then you shouldn't have any trouble with your power pack. You will need to set up your switch pannel so that as the train goes from one block to another you can switch the controler for that train to the new block. Only one train will run on a given block at a time. Then all you need is one or two more regular control boxes depending on how many trains you plan to run at any one time.
  5. Fred_M

    Fred_M Guest

    Clark, Only trouble with that is I sometimes run 4 or 5 locos as a consist and that powerpack wouldn't handle them. I'm thinking that's what CPRail is trying to do too. Fred
  6. Russ Bellinis

    Russ Bellinis Active Member

    I think you need a bigger power pack. You should be able to get a bigger MRC pack for a reasonable price from one of the big discount mail order/on line train stores like Train World, Standard Hobby Supply, etc. You might also put a "wanted" add in some of the model railroad sites like this one. The Tech 2 2400 or 2500 would be good choices. With the number of modelers switching to dcc, there might be some nice used power packs available. You might also check out ebay.
  7. Jodam

    Jodam Member

    I plan to use a 12V car battery as my power source, left on trickle charge.
    With control through a Talking Electronics Throttle cct. If extra amps are needed through the throttle i'll parallel up the output transistors. All accessories can then run off plug packs.
  8. jon-monon

    jon-monon Active Member

    I believe the MRC output is Pulse Width Modulated DC (PWM), which is esssntially a squarewave. It would be easer to build a new throttle than to add to the output of a PWM throttle.

    Jodam, I haven't looked at the TE throttle in a while. I hope it's a FET output. If not, you might look into a FET output throttle for high current. The beauty of a FET is that it conducts less as it heats up, resulting in automatic thermal protection. You can parallel two or more, and if one gets warm, it will essentially shut down and the other(s) will take over. Standard silicone transistors behave quite the oposite. FETs are suitable for DC or PWM. You can get power FETs for under $1. Let us know how your project goes!!!
  9. CPRail

    CPRail Member

    thanks guys for all the advice. i think i might put out some wanted posts on several MR fourms, and i'am going 2 look around at the different hobby shops for the MRC 2500. i guess the bigger the better because i want 2 run up 2 4 locos in one train!
  10. Fred_M

    Fred_M Guest

    Only one thing I wish to ask Damien, and it's just a question I wonder if you have thought about? Car batteries on trickel charge will emit a fine vapor of sulfuric acid as they charge which will over time corrode any metal in the room. Have you thought about this and took action to vent the battery outdoors? Fred
  11. Silicon

    Silicon New Member

    Yikes!:eek: Please tell me you're going to have a fuse or circuit breaker on the output. Car batteries can provide hundreds of amps of current, so a short could easily arc weld things to your track.
    The evaporating electrolyte in the battery is a long-term concern. But you should also be careful of the hydrogen gas (think "Hindenburg":eek:) produced by lead-acid batteries while they are charging.
  12. jon-monon

    jon-monon Active Member

    The track itself will serve as a 50 AMP fuse :D :D :D j/k

    I'm thinking the benifits of such a system won't outweigh the costs of a DC power supply that has a high enough current capacity to meet the pikes needs.

    12 V at 3 A for $10 (needs case and wiring, probably a load resistor or light bulb to meet minimum load when trains are not running.)
  13. Fred_M

    Fred_M Guest

    The booster we built was in the March 1973 issue of MR on page 62. Fred
  14. Jodam

    Jodam Member

    A note to allay your fears, this bloke from down under has no intention of blowing himself Up over :eek:
    I may be a renewing newbie in M/railways, however before being invalided out of the work force, i was an Electronics Engineer, with extensive experience in 12V home power systems, amongst many other things.

    That said the battery will be in a sealed box, similar to Race Cars, except it will vented via a fan to the outside via a catch tank/condenser for the fumes. As with any Electrical/Electronic application, Short/overload protection is a safety must.

    Hope this takes away the need for the Valium Guys.
    Cheers, Damien.
  15. Woodie

    Woodie Active Member

    Talkin; bout this sorta thing, has, or does anyone run their layout on solar power?
    Round my part of the world, it can cost a fortune to get the electricity connected. ($20 - $30,000 AUS), so they run their houses etc on solar panels.
  16. Jodam

    Jodam Member

    Hi woodie,
    The Solar systems, are configured in several ways. The most common i've worked on, have banks of either 2 or 12V batteries for storeing the Solar Energy, these can be Paralleled to give massive Amps at 12V or Series coupled to give 240V with several 240V banks in parallel. Most common is the 12V system running a High output inverter.
    The Solar Cells provide the Battery charging, in the main, if they're set up with sun tracking they are useful for daytime power as well.
    Although i've not been involved in this area for some time, Technology advavces may have progressed in leaps and bounds.
    Either of these systems will power Any Train controller, with the possible exception, of those that require a Sine wave AC input supply.

  17. jon-monon

    jon-monon Active Member

    Good to hear you will be OK Damien! So you can help us instead LOL

    Woody, look into solar panals for sail boats. Then use a marine deep cycle battery, monitor it's voltage so you don't discharge it too far, and you should be able to run all night and charge all day :D A lot cheaper than $20-30K!

    BTW: You can't run your own wiring to an outbuilding there? I think we can here, if not I would do it at night :)
  18. Woodie

    Woodie Active Member


    I've got no probs with mains power at my place. I am towards the "end of the line", though, so failures are quite common. Especially summertime when it's storm time. (thunder & lightning). Slighest flash and bbbbzzzzzzt..... off it goes.

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