| 摘要 |
Disclosed is a very low frequency (VLF) test generator (1) for generating a high voltage (Us) having a low frequency (fs) in order to test the insulation of capacitive loads (2), in particular power cables. Said VLF test generator (1) comprises two oscillators (6, 7), the frequencies (f1, f2) of which differ from one another by twice said low frequency (fs), a resonance circuit (8, 9) which is fed in an interfering manner by the oscillators (6, 7), is adjusted to the oscillator frequencies (f1, f2), and causes a voltage rise (UR) of the interfering oscillator frequencies, and a demodulator for disconnecting the low-frequency high voltage (Us) generated by the interference from the resonance circuit (8, 9) and applying the same to the load (2). |
