Can someone help clear this up?

Discussion in 'DCC & Electronics' started by vanda32547, Sep 20, 2004.

  1. vanda32547

    vanda32547 Member

    Since I am switching over to a DCC System I have been reading and researching the components I want to add to my layout...such as auto reverse looping, and switch machine control. Here is my question;

    I have been considering the the purchase of a few Lenz LS150 decoders to control my Atlas Snap type swtich machines, which seems to have the features I want for the price I can afford. :)

    However here is the confusion... :confused:
    It says this unit needs a seperate AC power supply to operate the switch machines. AC? :eek: I thought those were DC operated from my old setup transformer from the accessories terminals. Am I wrong? Is that AC as in 110 AC? Won't that blow out the little components inside those switch machines?

    I'm sorry to seem so dumb when it comes to this but I want to make sure I purchase the right equipment for my new layout.

    Thanks in advance,

    Attached Files:

  2. Gary Pfeil

    Gary Pfeil Active Member

    Twin coil switch machines will run on either AC or DC, 12 to 16 volts, at least when controlled conventionally. Apparently for DCC operation they are suggesting an AC power supply.

  3. siderod

    siderod Member

    DCC is both DC and AC...there is constantly about 18-volts DC to the track, hence the constant lighting, amoung other things. DCC, is an AC "signal" sent via the track to the decoder...the decoder converts (or decodes, hence the name) that signal and moves the locomotive or shuts the lights off, or whatever else.

    This is kinda off-topic, but it might help clear the confusion...AC or DC, it shouldn't matter
  4. Gary Pfeil

    Gary Pfeil Active Member

    DCC (at least Digitrax) systems actually have two outputs, track power and, in the case of Digitrax, loconet. The track power is actually a square wave AC. Both outputs carry the signals from the processor, only the track output is boosted to provide power to run locos. Since I have no interest in operating my turnouts with my DCC throttle, I'm not sure how the stationary decoders are wired to the processor, but I'm inclined to think it is from the Loconet, not track power. I would think the turnout decoder is simply turning power on and off to appropriate outputs to throw the turnout, and that the power supply that is being connected and disconnected is independent of the DCC system. Hence, the requirement of a seperate power supply. Why it has to be AC, I don't know. A look at the wiring diagram for the stationary decoders would be helpful.

  5. COlin_McLeod

    COlin_McLeod New Member

    Never coonect 110 AC to the track or point motors.
  6. SteamerFan

    SteamerFan Member

    Bob, All DCC systems suggest running non-track items on a second power supply. Usually you cantake that old DC power unit and plug any non-track items into it's AC outlet (which is usually 12 Volts).

    The LS150 is designed to handle up to 6 different turnouts, the manual states the following:

    And later goes on to with the following warning:
    So it seems that twincoil machines work better with AC rather than DC power.

    That said, the LS150 should use a 12 volt (they say max of 16, but i'd stick with 12-14) AC power supply seperate from the Power supply for your DCC system. the AC power supply will be connected to the Spot marked with the funky double wave with a line through it and the track leads would be connected to the JK terminals (this is just for the DCC signal, not power).

    Hope that helps.
  7. vanda32547

    vanda32547 Member


    THANKS....That helps me out alot and clears up my confusion with the whole DC/AC old transformer issue.

  8. Boyds-trains-WM

    Boyds-trains-WM New Member


    The use of AC seems to be a short cut to control the two wire LGB and motorized switch machines. I had forgotten the LGB operation until my son needed some help with it. LGB uses AC and diodes to be able to change the polarity on the two wires controlling switch machine (instead of a DPDT switch and DC, or three wires etc.). Figure 1 of the user manual downloaded from the Lenz web site shows a motorized switch machine hooked up with a couple of diodes; I believe the LGB machine with its two wires will connect the same way. Though, unless I got my brain on backwards at the moment, the way the diodes are connected are opposite the polarity of the markings on the device (not that it should exactly matter it seams as long as it is matches the desired switch action).
    ( )
    ( )

    Otherwise adapters like the two transistor circuit for the LS-100 shown on
    ( )
    are needed (or more complicated and expensive circuitry in the device).

    Happy trains,
  9. kchronister

    kchronister Member

    I'm on the Lenz system and run my switches with LS150's. I use the "accessory" AC output from my old DC power supply to supply the juice, which has worked perfectly.
  10. vanda32547

    vanda32547 Member

    That is what I decided to try...

    That is exactly what I decided to do. :D
    However I noticed that the maximum number of turnouts I can control on a route is 3. :(

    I wonder if a better power supply might give me capability of contolling more?


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