Operating mechanism for doors of model railway carriages - uses diodes connected in parallel with solenoids to open or close doors

摘要

The doors (1) of the carriage of a model railway are mounted on hinges attached to the door frame (2). A double solenoid (3) (4) with a common armature (5) is mounted above the door. The mid-point of the armature (15) is connected by pivoted rods (6) (7) to the edges of the doors (1). the solenoids (3) (4) are connected in series and a diode is connected in parallel with each solenoid. When a voltage is applied to the circuit the current is blocked by one diode so that the current flows through its associated solenoid. The other diode permits the flow of current so that its associated solenoid is by-passed. When the current flow is reversed the actions of the solenoids are reversed. Thus one solenoid (3) opens the doors and the other solenoid (4) closes the doors.