| 摘要 |
Means for detecting a metallic object comprises a coil system with a transmitter coil (5) for generating an electromagnetic field and a receiver coil (6) subject to an electromotive force induced by the resultant of the field generated by a metallic object and the field generated directly by the transmitter coil (5). An oscillator (1) is provided for generating a sinusoidal signal for the transmitter coil (5) and a variable attenuation or amplification circuit (2) is provided for controlling the amplitude of the signal, this circuit (2) being controlled by a signal (Im) emitted by the coil system and then rectified (8) and compared (9) with a reference voltage (Uref), the arrangement being such as to control the amplitude of said electromagnetic field. In an alternative embodiment (Figure 2) the signal emitted by the transmitter coil itself is rectified and compared with Uref. The detection means may be used in an electromagnetic proximity fuze. <IMAGE> |
