| 摘要 |
The vehicle alarm has an elastic tube contg. a deformation sensor with a circuit triggering an alarm when a defined degree of deformation is exceeded. It is applicable to safety of passengers in buses etc. when the doors are closing, and has a high degree of sensitivity independent of time and ambient influences. The tube (2) deformation sensor consists of a light source (3) and receiver (4) between which a light beam acts as a signal medium. A circuit dependent on the output signal of the light receiver regulates the intensity of the light source so as to compensate a variation in the light intensity received by the receiver. The circuit starts to react after a certain delay following the beginning of the variation in the receiver signal caused by the intensity variation. - |
