PURPOSE: To guarantee a fail-safe operation by outputting a brake command signal, when a train speed exceeds a limiting speed, by periodically checking whether an information through the output of a comparing means and speed information generating means is correct or not, and by outputting a brake signal also when the same check signal is outputted continuously.
CONSTITUTION: A signal as to whether a train speed deviates from a speed zone or not is outputted from speed comparing slots C1, C2. A signal as to whether the train speed exceeds a limiting speed or not is outputted from a speed comparing slot C3. A signal as to whether a tachometer generator 38 is out of order or not is outputted from a speed comparing slot C4. These signals are transmitted to a comparison results summarizing part 46. From a fault detection slot C5, an alternating signal, of which check results are alternately correct or incorrect, is generated normally and a high-level or low-level DC signal is continuously outputted at an abnormal time. When said output signal is inputted to an output gate 48, a brake command signal 106 is outputted to a braking part 36 and a braking force is given to a train.
TOYODA EIICHI
SEKINO SHINICHI