The main characteristics of the adjustable capacity power frequency series resonance AC withstand voltage test device are:
(a) Lightweight, requires small power capacity, and outputs a 50HZ power frequency voltage.
(b) The resonant frequency of the test device is fixed at 50Hz, and the combination of fixed inductance and tuning capacitor is adjusted to achieve resonance in the test circuit. Due to the fixed inductance of each tuning inductor and the capacitance of the tuning capacitor, different combinations can only be used to make the inductance and capacitance values of the test circuit as equal as possible. Therefore, the adjustment is not very convenient and the quality factor is relatively low (generally less than 40).
(c) The device adopts unidirectional power supply and requires a large input current.
(d) The frequency of the test power supply is fixed at 50Hz, and a portable self coupling regulator is used to adjust the input voltage. Since the capacity of the regulator is not large, it is required that the capacity of the tested object should not be too large, and there should be slight distortion in the test voltage waveform.
(e) The volume of inductance is relatively large.
(f) Suitable for AC withstand voltage testing of specimens with small capacitance.
(g) The voltage regulator in the device has moving components, which have a short mechanical life.