| 摘要 |
PROBLEM TO BE SOLVED: To output a signal for indicating the capacity of a capacitive sensor as a digital signal by a simple configuration without any high voltage sources. SOLUTION: In this signal-processing circuit, one electrode of a capacitance microphone type detector 1 is alternately connected to a voltage source 2 and a distribution capacitor 3 by the switching of a switch SW1. The number of times for changing a switch SW1 is counted by a counter 7. When the voltage between both the poles of the distribution capacitor 3 exceeds a specific value Vs, a comparator 4 outputs a signal to a latch circuit 8, thus latching the count value of the counter 7, and outputting the latched value as a signal for indicating the capacitance of the capacitance microphone type detector 1.
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