| 摘要 |
PURPOSE:To enable the use of a battery as a power source by achieving the reduction of power consumption by intermittent driving, by applying a high frequency signal to the power amplifier for a detection coil only for the output period of an intermittent signal. CONSTITUTION:The oscillation output of a quartz oscillator subjected to 1/2-frequency dividing by a binary counter 2 is counted by a preset counter 6 which in turn outputs a pulse with predetermined amplitude and a predetermined cycle every when the counted value reaches predetermined numbers corresponding to the preset due to a cycle setting device 5 to open an AND gate 3. Whereupon, the high frequency signal from the counter 2 through the gate 3 is applied to a power amplifier 7 and metal detecting coils 9, 10 are driven through a transformer 8. By this intermittent driving, the power consumption of a metal detector is reduced and a battery is used as a power source to enable the portable use of the metal detector. |
