| 摘要 |
<p>The generator has a piezoelectric elements (1) comprising a disc (2) of ceramic or crystal, and two electrodes (3,4). The thickness of the disc (2) is relatively greater than the thickness of the pickoff disc to be calibrated. A capacitor (10) is used in series with the piezoelectric element (1). The voltage across the capacitor (10) is used to measure the electrostatic charge of the piezoelectric element (1). The generator also has a supply circuit to produce a short duration pulse and a known electric charge. A direct current supply (5) in series with a variable resistor (9), a fixed resistor (8) and a shunted diode charges the piezoelectric element (1). An avalanche circuit comprising an auxiliary pulse generator (13) and three transistors (T1,T2,T3) discharges the piezoelectric element (1) after a short time duration.</p> |
