SPEED SCANNER FOR AUTOMATIC TRAIN STOP SYSTEM

摘要

PURPOSE:To eliminate fail-out elements upon breakdown of individual elements, by carrying out speed scanning based on an Ac logic. CONSTITUTION:A limit speed is set in a speed pulse count setting section 3 while the diameter of wheel and the number of tooth at speed reducing section are set in a comparison clock pulse setting section 4. A counter 1 counts rotary speed pulses corresponding to the limit speed and provides a carry signal every time when counting is finished. A counter 2 counts a high speed clock pulse signal between the output carry signals from the counter 1, and provides a carry output signal if the value thereof exceeds over a preset value. Then the signal is converted at a frequency converting section 5 into an AC signal of about 200Hz then it is converted at an AC/DC converting section 6 into a DC signal, i.e. a brake output.