Early Proto-Sound Equipped Engine Compatibility With DCS

Early Proto-Sound equipped engines (PS1) built in 1995 and 1996 suffered operating anomalies when used with "shark-fin" or phase control AC Waveforms found in the AC track voltage of what were then considered modern-type transformers. Older transformers, like Lionel's ZW model or MTH's then newly released Z-4000 employed a more "pure" sine wave form of current for which the PS1 system was specifically designed.

Because these newer transformers could cause the sound system to act irregularly, MTH chose to disallow operation with any transformer type affected by the shark fin wave form rather than suffer complaints that the engine was defective. The affected transformer types were not listed in the approved transformer list found inside each engine produced during those years. Because so few of these "modern" transformers existed in the marketplace few consumers experienced the automatic transformer rejection.

By 1997, software designers had pinpointed the shark-fin problem and resolved it through software and hardware changes in the PS1 circuit board. Consequently 1997 and later PS1 engines do not require the shark-fin transformer rejection needed in 1995 and 1996.

Users of DCS may have experienced the shark-fin rejection when attempting to run those engines on a variable channel. This is because the DCS Track Interface Unit (or TIU) does not employ the more expensive pure sine wave form of current found in the MTH Z-4000 and instead relies on the less expensive phase control AC waveform. While the TIU waveform isn't as pronounced as that found in those early mid-1990's transformers, the PS1 software will still reject the current and not allow the locomotive to leave the RESET state.

DCS users experiencing this phenomenon should follow either of the following procedures to allow their PS1 engines to operate with the DCS system.

Z-4000 Remote Receiver Method

  1. With the PS1 engine on the track, employ the use of the MTH Z-4000 transformer for powering the variable or fixed channels of the TIU.
  2. Configure the TIU for a Z4K Channel. There are two ways to do this. Either step requires the use of the Z-4000 remote receiver (MTH part number 40-4002)
    1. Configure the Fixed channel by setting it up through the TIU setup menu as a Z4K channel.
    2. If using 2.1 software, you can configure a variable channel as a fixed channel as well. Once configured as a fixed channel via the TIU setup menu, the channel can be used as a Z4K channel.
  3. Give the fixed (or variable configured as fixed) Z4K channel full power from the Z-4000 transformer.
  4. Use the DCS remote to access the Z4K channels and adjust the track current appropriately to operate your PS1 locomotive. The shark-fin rejection will be disabled because the TIU is receiving full power from the Z-4000 transformer. The combination of full power with the use of the Z4K receiver eliminates the need for the TIU to regulate the current from the TIU to the track and thus does not "contaminate" the track current with a shark fin or phase control wave form. As a result, the track current isn't rejected by the PS1 hardware and the locomotive should operate normally.
  5. The engine will continue to function and respond to DCS commands as long as it is not shut down. When shut down, repeat the above procedure to get the engine to respond again.

Sine-Wave Trick Method

  1. With the PS1 engine on the track, employ the use of an MTH Z-4000 transformer or any older Lionel ZW or KW type transformer as the power supply for the Variable Channels.
  2. Apply power only to the TIU via either the Fixed 1 or Auxiliary Power input. Do not apply power to the variable channel at this time.
  3. Scroll the variable track voltage up to 22 volts using the DCS remote.
  4. Now apply 8 - 10 volts of current from the transformer to the Variable Channel you wish to control. At this point you have tricked the TIU into thinking it is passing current straight to the track and the PS1 locomotive should start up.
  5. Press the red Direction button on the remote to allow the PS1 engine to leave Reset. Press DIR again to park the engine in neutral.
  6. Adjust the transformer throttle up to full voltage. And lower the DCS voltage setting down to the desired operating voltage the user wishes to apply to the engine.
  7. The engine will now continue to function and respond to DCS conventional commands as long as it is not shut down. When shut down, repeat the above procedure to get the engine to respond again.

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