Sumpthin fer electronal weenies to think about

Discussion in 'FAQs' started by jon-monon, Nov 27, 2002.

  1. jon-monon

    jon-monon Active Member

    Last night I was runnin' my "new" Fleischmann switcher around and round the test loop. It runs pretty smooth. It's got a coil (choke) in series with the motor. What would the effect be. Oppses AC or changes in DC. So, what's the effect? Smoother starts and stops? Sort of electronic flywheel? I don't think this particular coil is big enought o have a significant effect. It responded well to pulsing, and I would expect a coil to remove the pulses or smooth them out. How about a big cap between the "rails" or across, parallel with motor? It should atleast give a little coasting action. I might play with some big caps. I'm going to build a high freq pulse DC supply and I might put an RC on the control circuit so as you cut back quickly, the pulses get narrower slowly. Any thots? Is anyone else interested in making their own hi end analog supply?
  2. RailRon

    RailRon Active Member

    Hi Jon,
    electric motors back in the 50's and 60's did quite a lot of sparking with their brushes. I had a loco then whose commutator sparked so badly that she really STANK from ozone. If we had such motors today, environmentalists would try to ban model railroading because of the danger of poisoning the whole neighborhood with ozone! :D :D :D
    This sparking also caused interference with the radios. You ran your model railroad OR you listened to the radio.
    Then the German manufacturers started to add these choke coils to kill the high frequency noise. When memory serves me right, in Geremany they even had a law (enforced by the postal services) which obliged the manufacturers to add these gizmos to model motors.
    If this choke coil combined with a hi freq DC supply has any side effect I don't know, though. Just one way to know: Put the loco on the track, power ON and --- SMOKE TEST ;)
    (What smokes first, the loco or the power supply???)
  3. Vic

    Vic Active Member

    Hey Jon, the choke coil is for EFI, RFI and TVI supression. Small DC motors can kick up quite an electrical racket at certain frequencies and European radio and TV falls within those frequencies. Most motors for R/C race cars use a capacitor across both brush terminals of the motor to accomplish the same keep the RFI of the motor from interfering with the radio control receiver.
  4. jon-monon

    jon-monon Active Member

    Oh, yes, I shoulda thota that. I have a pocket full of FETs and 555 timers and some vector board, so I'm ready to go on a new power supply. I'm going to go for about 20 KHz, or whereever my ears stop hearing it. Should keep the motors cool, the torq. hi and the yard master happy :D :D :D
  5. tomfassett

    tomfassett Member

    Oh man, you're gonna' set the drapes afire one of these days, I just know it!...:eek: :rolleyes: :p

    Tom F
  6. tomfassett

    tomfassett Member

    One more thing. If you are going to play with caps, don't make the same mistake I did and assume "blasting caps" hold a charge better than an electrolytic. I got a charge out of it when I put a charge in, but I was unable to duplicate the results as I could not find enough pieces of the loco to make a decent scrap pile on the layout...:D Next time, I'm going to have one of the gandy dudes switch the power since they need the work...

    Tom F
  7. rich maiorano

    rich maiorano Member

    i got a couple of narrow gauge engines that have that coil on them only one works the others are in parts got them in with alot of n-scale stuff cool little engine:D :D :D
    ps I was wondering what that coil was for it was the first time I ever saw one:D :D :D :D :D rich
  8. shamus

    shamus Registered Member

    Hi Jon,
    Most of the loco's back in my good old days had these radio supression coils fitted to the motor, didn't seem to do alot of good, but they were there. Come to think of it, my shay could do with one on as I cannot listen to my CD player when she runs around. Too much crackle.

  9. kf4jqd

    kf4jqd Active Member

    Thanks for the Reminder, Vic!

    I will have to remember about this little tid bit of information when I get on 160M. I imagine the FCC wouldn't like it if I cause interference over a broad specturm of frequencies! I wonder if Uncle Charlie would fine me if my Athearn caused RFI on 80m? What do you think Vic?

  10. Vic

    Vic Active Member

    Hi Andy, don't think that it's gonna cause any RFI to anyone but you!!!:D :D .... kinda like an electric shaver running when the radio is on:D :D 'Course I do recall the Sun night you were runinng trains, talking on the 2 meter net and talking to me via the computer:) :D :D

    Course there is a simple solution...go buy you one of those whiz-bang $5,000 transcievers:D :D :D

    73, K4VIC

    BTW...Did you ever get Echo-Link? If so and if you see W4CVY/R on the list connect to it and give me a call. I monitor that one.
  11. kf4jqd

    kf4jqd Active Member

    Echo Link

    I do have Echo Link. However, with my poor IP connection. I am very choppy!:eek: I will give it a try sometime.

    As for talking on the 2m repeaters and running trains. They can hear bells in the background and call it QRN. Not me! Most of the time I get the question. "Is that a train I hear in the background?" Of course I have to say, "Yes it is!"

    I have to decide to ask Santa if I want some Rock Island stuff or an Icom 706. Maybe I'll get both!:D

  12. McFortner

    McFortner Member

    Well, I would have to ask for a house so I can set up both a train room and a radio room. Living in a ground floor apartment makes it hard to set up both a train layout and working anything below 2 meters a bear.

    Well, maybe next year? :confused:

    73 de N0YBC/5

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