| 摘要 |
Two reed switches are alternately closed by a magnet rotating with a shaft of a water meter or the like which is to be read remotely. A capacitor discharges through the reed switches when the same are closed, increasing the switch current without increasing the external power source current, thereby producing temporary partial fusion of the switch contacts and maximum contact effectiveness. A low-pass filter and a snap action circuit such as a Schmitt trigger are connected to the switches to eliminate the effects of contact bouncing and noise signals from the output of the circuit.
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