| 摘要 |
PROBLEM TO BE SOLVED: To provide a pressure sensor unit, capable of reducing a distributed capacity caused by a lead wire for connecting a capacitance type pressure sensor to a capacitance value/voltage value conversion circuit or a capacitance value/oscillation frequency conversion circuit, in which the detected minute capacitance value is hardly influenced by the distributed capacity, caused by the lead wire or the influence of an external noise. SOLUTION: This sensor unit is equipped with the capacitance type pressure sensor 4, formed by facing a plate spring 11 made of a phosphor bronze plate to a conductor part 2 formed on an insulating substrate 5, and by arranging them at a prescribed gap though plural spacers 3A, 3B, and the capacitance value/voltage value conversion circuit 7 (or capacitance value/oscillation frequency conversion circuit 8), for detecting the magnitude of the pressure applied on the plate spring 1 as a change of the capacitance value between the plate spring 1 and the conductor part 2, and converting the change in the capacitance value into a voltage or an oscillation frequency and outputting it. The sensor unit is formed, so that the output of the capacitance type pressure sensor 4 is inputted directly into the capacitance value/voltage value conversion circuit 7 (8) which is arranged integrally on the insulting substrate 5.
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