| 摘要 |
PURPOSE: An electrostatic-capacity level sensor is provided to control the contact sensitivity of electrode to liquid by controlling voltage applied to the electrode by a parameter when the electrode and a container form a condenser. CONSTITUTION: An electrostatic-capacity level sensor comprises an electrode(16), an oscillation circuit(22), a voltage control circuit(24), a detection circuit(26), a reference voltage circuit(28) and a comparison circuit(30). The oscillation circuit oscillates high-frequency voltage applying to the electrode. The voltage control circuit changes the high-frequency voltage. The detection circuit detects the change of the voltage in the electrode. The voltage reference circuit generates reference voltage, which determines the contact sensitivity of the electrode to liquid. The comparison circuit compares the voltage from the detection circuit with the reference voltage.
|
