Originally Posted by F&G RY:
How does it work? With a disc on a arm that would open and cover the holes with a shaft or rod? Or with 5 bulbs, like the 440?
They directions imply one bulb.
My guess is there's one bulb in the head which lights up the chamber inside the head. The center hole in the face is always open and the light shines out thru it. The solenoid, activated by track trip, pulls the rod down which turns the disc a few degrees: holes in the disc are arranged so that when rotated, the horizontal holes in the face are uncovered and the light shines out, but the vertical holes in the face are covered. When the train passes, there is no longer power to the solenoid, and either a spring or gravity returns the disc to its default position, covering the horizontal holes and uncovering the vertical holes in the face which the light then shines out through.
The two green wires are hot and common for the light. They are wired to track or accessory power 12V so they are on all the time.
The two black wires are hot and common to the solenoid. The hot is wired to track or accessory power 12V. The common to the solenoid is attached to the outside rail of an insulated track section, or other trip device.
At least, sight unseen, that's how I can best explain and reconcile Marty's findings, the instruction sheet, the Greenberg description, and keeping in mind that Marx accessories were as simply and inexpensively made as possible.
It's pretty ingenious, this little device.