| 摘要 |
PROBLEM TO BE SOLVED: To provide a capacitance detector which is small in the radiation noise coming from an oscillation circuit. SOLUTION: This capacitance detector for detecting a capacitance C4 by using an oscillation signal of the oscillation circuit 10 includes: a hopping means 30, TR1, C2 subjecting the oscillation frequency of the oscillation circuit to frequency hopping by a pseudo-random signal; and a detection means 40 for detecting the capacitance using the oscillation signal subjected to the frequency hopping. Frequency hopping is carried out, by changing over the capacitance of an LC resonance circuit by the pseudo-random signal, or is carried out by adjusting the variable capacitance diode of the LC resonance circuit by an analog signal generated from the pseudo-random signal. COPYRIGHT: (C)2009,JPO&INPIT
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