Credit-card sized infrared badge communicator system for user identification

摘要

The infrared badge communicator system is a thin card with a self contained battery (12,13) and having two receive infra-red diodes (1,2) to switch on and off the battery. The first infra-red diode is connected across a transformer to a transistor (15) connected across a transformer to a transistor (15) connected across the battery, so that when a coded signal is received the battery is turned on. The second diode is connected via a line and capacitor to the transistor, which is switched off and prevents current flow in the feed circuit (36,37). When the battery is switched on, a transmitter infra-red diode is operated transmitting coded signals.