Hoist drive control system with encoder and decoder - galvanically sepd. by opto-isolator in data lines powered by 40 V line driver for interference suppression

摘要

An overhead travelling hoist is operated from a sliding suspended switch unit (2) in which an encoder (7) scans the switch elements (6) at intervals of about 15 ms, sending signals over two data lines (8) to an opto-isolator (9) in a decoding unit (10) connected to the power lines (5). The data transmission cable (3) includes also two power supply lines (13) for the encoder (7). An additional switch (15) is provided on the suspended unit (2) and connected to a separate control line (14) for emergency stop purposes. ADVANTAGE - Fewer control wires are needed with commercially available components of control system.