question about transformers

Discussion in 'HO Scale Model Trains' started by yronbay, Aug 9, 2004.

  1. yronbay

    yronbay New Member

    Hi folks - I'm new to the forum.
    My sons love Thomas the Tank and I've picked up several of the new Bachman engines (Thomas/Percy/James) as a way to transition them from the wooden toys to the world of model railroading. I got only the engines - not the 'starter set' packages. I'm trying to run these on my dad's old HO layout that he pieced together many years ago. The transformers I have are old Tyco gold boxes - probably about 20-25 yrs old (some of this layout was actually mine when I was a teenager). They still work because all of our old engines run fine with them. However, when I put the new Bachman engines on the layout, even when I just barely turn the transformer on, they take off like a bat out of he** and run off the track because they can't take the corners that fast. Have things changed in the specs of how HO works these days compared with older sets, or is something else amiss here? Do I need a new/different type of transformer for these engines to get them to slow down? Any suggestions/recommendations?

    Also - these Bachman engines and cars seem to have trouble staying on the tracks of this old layout (my old trains do fine). I'm not sure if this is related to the engines running too fast or if it is a separate problem.

    Thanks for any advice!
  2. Fred_M

    Fred_M Guest

    Thomas uses less amps than the old HO locos did and run like you say with them older rheostat transformers. A newer MRC powerpack will fix that. As to staying on the corners that is a problem with Thomas and his friends. They sell him as a starter unit but in a lot of ways he is harder to run than a medium quality Athearns or Proto 2000, etc. loco. Thomas also don't handle turnouts too well either. Thomas also don't handle dirty track too well. That's why I kind of dislike Thomas in HO. They tend to sour the spirits of new people to the hobby who get them not realizing they are some of the poorest running locos sold. My grandkids have Thomas but never run him, instead they run a $3x dollar Athearns F-7 pulling $6 gondolas with which they do things like hauling Thomas and his friends to the junkyard. I'm serious, they actually do that as one of their games. They are 7 and 4. Fred
    PS Welcome to the Gauge.
  3. jwmurrayjr

    jwmurrayjr Member

    Thomas can be made to run pretty well with DCC but he's still finicky about dirt.

    A new MRC DC pack would probably make all of your trains run better.

    Have fun,
  4. RioGrande

    RioGrande Member

    The problem with some locomotives, is the fewer the wheels, the less there is in contact with the track to pick up electricity reliably. Most American diesels have 8 wheels on the tracks and that works well... Thomas has only 6, and it makes a difference. I've had that old Bachman 4 wheel switcher which didn't pick up power very well at all.
  5. Vic

    Vic Active Member

    I dug one of those old Tyco Gold Boxes out of the junk box and made a couple of measurements on it.

    Under no load conditions the starting voltage is 6.3VDC. With a load, the motor from a Tyco/Mantua Pacific, starting voltage dropped to 4.0 volts.

    Those old power packs were designed to operate open frame motors which had a high start voltage. The Thomas engine probably has a start voltage of around 2 VDC with a draw of less than .25AMP so its gonna go like a rocket when you just crack the throttle. Any newer power pack would not have that problem.

    Hope this helped.
  6. Fred_M

    Fred_M Guest

    Just a note for Vic and whoever else cares, I tried Thomas with a "brown plastic" bachmann style powerpack from an HO kit from the "trash box". He won't stop moving on clean track. :) I was running him on a homemade power supply made from an LM350 voltage regulator. Fred
  7. pjb

    pjb Member

    Just put some resistance (lamps, etc.)in the circuit
    between the Powerpack and track connection and the
    remaining juice will operate your new Bachmann toy train.
    As noted elsewhere, if you want to do more and stay
    at running trains, then you should buy other components.
    Good-Luck, PJB

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