| 摘要 |
PURPOSE:To reduce a consumption electric current and to measure flow rate strong in noise with high reliability by confirming both states when a read switch is on or off and then, first processing count of the flow rate. CONSTITUTION:In case the reed switch is on, the voltages of both ends of a capacitor 3 of the 1st series circuit are monitored with a signal processing circuit 8 with the timing when the pulse voltages are generated on both ends of resistance 4 of the 2nd series circuit by the electric discharge of the capacitor 3 of the 1st series circuit and further, in case the switch 1 is returned to off by an OR circuit 7, the voltages of both ends of the capacitor 3 of the 1st series circuit are similarly monitored with the circuit 8 with the timing when the pulse voltage is generated on output of a trailing edge detection circuit 6. Then, the count of the flow rate is first processed with the circuit 8 when the states of an and off are detected. As a result, the flow rate can be measured with the high reliability without a fear of the wrong count even if the pulse voltage by the noise is generated when the reed switch is on.
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