| 摘要 |
Metal locating instruments are used in the household field for locating metal objects located in masonry, especially electric wires. A method for distinguishing such metal objects from voltage-carrying electric wires is known, in which the electromagnetic alternating field of the voltage-carrying electric wire is received by an antenna, amplified and indicated by means of a signal lamp. In order to locate an electric wire, especially one laid in masonry, an alternating voltage is superposed on a pulse generated by an audio frequency transmitter, and the combined signal generated in this way is coupled capacitively to the wire. For the superpositioning, two transistors in push-pull operation are described, which are connected to the audio frequency transmitter.
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