| 摘要 |
<p>The device enables the conventional mechanical vibrator in d.c. to a.c. converter to be replaced by an electronic generator. This allows higher reliability, lower unit weight and higher output voltage, which allows high probe shunt capacitance measurements to be tolerated. A conventional a stable multivibrator generates a variable frequency signal which is power amplified and applied to the primary of a high turns-ratio transformer (11). Robust anti-surge damping circuitry (19, 22) prevents damage due to shorting of the secondary. The output voltage, multiplied (12) to a max. of 25kV, is applied via a probe (6) to the insulation test piece. A circuit (13) sensing the potential of a probe voltage reference point (24) activates an alarm (14) in the event of insulation breakdown causing a short circuit condition.</p> |
