| 摘要 |
PURPOSE:To detect troubles such as disconnection or short-circuiting of an output signal transmission line by connecting a voltage detection element in series to a detection coil in a vibration sensor designed to detect vibration with the detection coil. CONSTITUTION:Direct current flows through resistances 21 and 12 by way of a detection coil 11 built into a vibration sensor 1 and a split-point voltage Vs develops at the receiving end (a). In case an output signal transmission line of the detection coil 11 is short-circuited to an earth electrode, DC voltage at the receiving end (a) is made down to zero or a very low level and the voltage end (a) is made down to zero or a very low level and the voltage level of the inversion input of a first comparator 31 falls so much below the Vref 1 that the output turns to the high level from the low level. In case disconnection occurs in the detection coil 11 or the output signal transmission line, the DC voltage at the receiving end (a) becomes the power source voltage level Vcc and the voltage level of the non-inversion input of a second comparator 32 rises so much above the Vref 2 thereby, the output turns to the high level from the low level. |
