Automatic door opening system for apartment building - has rest contact in door opening line providing feedback signal to display stage in series with opening button

摘要

The door opening system allows the main door to be opened upon operation of a door opening button (1) provided in each apartment, upon the caller being interrogated via an intercom system. The opening and subsequent re-closing of the door is detected via a rest contact (6) inserted in the door opening line (4), with a display stage (3) provided in series with the door opening button (1) within each apartment. Pref. the rest contact (6) is provided by a sensor responding to the door being opened, the delay stage (3) pref. using a LED in parallel with a resistor. ADVANTAGE - Provides feedback signal when door is opened.