Automatic control circuit for compressed air operated doors - uses resistance voltage divider network to control transistor which reverses operation of door valve

摘要

The automatic control system for compressed air operated droos has a logic circuit. Associated with the logic circuit is a central control circuit which controls the door valve. This door valve opens a door or doors when an opening order is actuated by a passenger and the door control is released by the driver. A similar procedure is used for door closing, except that there is an opening maintenance time period for certain doors. The logic circuit has a resistance network whose resistance ratio are determined. This resistance network is made up of several voltage dividers which are combined with diodes. Whilst these resistors can be grouped and act with the diodes by adjusted potentials, the potentials applied to the dividers determine the control of a transistor. This transistor causes inverse operation of the door valve.