| 摘要 |
An improved transceiver for use in ultrasonic echo-ranging systems is disclosed together with a system for its use. The transceiver comprises a capacitor to store power received from a central location during an inactive mode, and switching means to disconnect the capacitor from the power supply during the active mode. The capacitor is used both to supply power to an electrostatic transducer to generate an ultrasonic pulse and also to provide a noise free bias voltage to the transducer to enable it to receive the reflected pulse. An amplifier is provided as part of the transceiver so that long transmission lines between transceiver and controller are possible without undue noise. The power supply line can also be used as the signal transmission line and can be provided in a simple two-wire shielded cable, the other wire being used for logic level control signal transmission, thus allowing simplified multiplexing of a plurality of transceivers.
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