| 摘要 |
<p>PURPOSE:To prevent the burning of a rheostatic brake resistor by automatically opening a rheostatic brake command circuit after a fixed time passes after a braking command from a motorman's seat is transmitted. CONSTITUTION:When a brake command is outputted to a brake command line (a) line or (b) line from a motorman's seat, a line breaker 15 switching a main motor circuit through an auxiliary contact 7 for a reverser and an auxiliary contact 8 for a braking changeover switch and a cam shaft controller 9 for constituting a rheostatic brake circuit are excited. When a brake command is outputted, on the other hand, a relay 10 is excited, a contact 10a is closed, and a relay 12 is operated after the set time of a timer 11. Consequently, a contact 12a is opened, the line breaker 15 and the cam shaft controller 9 are demagnetized, and the rheostatic brake circuit is opened. Accordingly, the burden of braking force on the rheostatic brake system electric car side is reduced, thus preventing the burning of a main resistor.</p> |
