| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid level detector preventing DC power from being applied to a liquid level sensor via an AC voltage generation circuit when a microcomputer stops its operation. SOLUTION: The liquid level detector 1 includes a CPU 55 for controlling a main unit and also generating an AC signal, the AC voltage generation circuit 70 for supplying AC voltage in response to the AC signal to the liquid level sensor 63 for sensing a level 62a of a liquid reserved in a predetermined vessel 61, a liquid level detection circuit 52 connected with the circuit 70 for detecting a change in voltage of the liquid level sensor 63 due to the change in the liquid level 62a and informing the CPU 55 of the change, and a power-off part 2 for cutting the power supply from the circuit 70 to the sensor 63 when the AC signal stops. COPYRIGHT: (C)2009,JPO&INPIT
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