| 摘要 |
<p>PURPOSE:To reduce the current consumption and enable long-time use with simple, small-sized constitution by detecting an external fine shock sensitively by a piezoelectric element and operating an FET for the 1st time with a piezo- voltage which is generated at this time. CONSTITUTION:The shock which is applied from outside is transduced by the piezoelectric element (piezoelectric element speaker) 10 into the pizeo-voltage, which is applied to the gate terminal G of an FET switching element 18. The base input voltage of the element 18, therefore, varies. The element 18 has the source S connected to a power source through a sensitivity adjusting resistance 14 and the drain D grounded through the parallel circuit of a resistance 20 and a capacitor 22. The element 18 turns on when the piezo-voltage exceeds a specific value. Only the elements 10 and 18 are in a stand-by state for monitoring the shock as mentioned above, the element 10 consumes no current, and the current consumption element 18 is nearly zero since the element is a voltage driven type. The total current consumption is considered to nearly be zero even while the elements 10 and 18 are in the shock monitoring stand-by state.</p> |
