| 摘要 |
PURPOSE:To monitor the air-pressure of tyre through means only at the body side, by sensing rotation of each wheel through sensors then specifying the wheel having different rotation (a tyre having abnormal air-pressure) and producing an alarm. CONSTITUTION:A rotation sensor 3 is provided in the vicinity of each wheel then the output signal from each sensor 3 is shaped 9 and provided to a pulse interval counter 10 to count the pulse interval. The output from said circuit 10 is stored in a memory 11 and updated every time when the pulse interval is measured. Then the output from each memory 11 is scanned sequentially by a comparator 13 and compared with the content in a maximum level memory 12 and if the scanned memory content is higher, it is stored in the memory 12. Thereafter the output from a divider 14 for obtaining the ratio (a) between the outputs from said memories 11 and 12 is compared with a constant beta in a comparator 15, and if alpha<beta an alarm 18 for corresponding wheel is operated through a flipflop 16. |
