| 摘要 |
<p>PURPOSE:To facilitate a balance adjusting work by arranging a voice device or a light emitting device to indicate an output voltage level of an imbalance signal which is generated due to deviations in position and diameter of a transmitting coil and a receiving coil. CONSTITUTION:After detected 14, an imbalance output of an amplification circuit 13 is passed through a filter 15 and converted 16 to a digital signal. An imbalance output level is applied to a voice device 23 or a light emitting device through a switch 20 to be outputted as changes in sound volume and an intermittent interval or the quantity of light and the intermittent interval. When there are any deviation in relative position between a transmitting coil P and receiving coils S1 and S2 and the like and than in the diameter of the coils and the like, an imbalance output is generated in a blancing circuit even if no metal exists. Thus, prior to the detection of metal, a balance adjustment is performed to zero a balance output.</p> |
