HardwareTrain Track(1) Staging Yard 3 LED Signals This is an update to the 5vdc tri-color LED signal for the staging yard. The polarity has been changed to common +5vdc to match the configuration of the dwarf signals also used in the staging yard. Or the dwarf signal lights. with adaptor boards. Copyright © 1 June 2019 - 2022 by No One's Business. All Rights Reserved.