Abstract: Prior to beginning a dielectric withstand (leakage current) or insulative impedance test, but after applying the high voltage that will be used in the test, the temporary charging currents resulting from application of the high voltage are measured and analyzed to determine if the test sample is properly connected to the test apparatus. If no charging currents are measured, or if the insulation resistance is too high, then it is determined that the test sample is not properly connected and the test is terminated.

Abstract: An output open circuit test method including the steps of inputting the data of a predetermined charging current upper limit value and a predetermined test voltage and a predetermine test charging current time zone into a test apparatus, then employing a high voltage to the test sample, and then driving the test apparatus to measure the current between two ends of the test sample and to compare the measured current value with the predetermined charging current upper limit value, and then letting the test apparatus to start testing the leakage current of the test sample when the measured current value is below the predetermined charging current upper limit value.

Abstract: A high-voltage power supply circuit consisting of an amplifier, a sine wave generating circuit, an AC/DC converter, a microcontroller, a transformer, a rectifier diode, a filter capacitor, a first switch, and a second switch, in which the execution of the control program of the microcontroller controls the setting of the frequency of the sine wave signal, the start of the sine wave signal, the end of the sine wave signal, and the opening or closing of the relay switches; in which the sine wave signal from the sine wave generating circuit is amplified by an amplifier, boosted by a transformer, then rectified by a rectifier diode, and then filtered by a filter capacitor for output, or for feeding back to a negative terminal of the amplifier for comparison with the voltage at its positive terminal so as to stabilize the output voltage; and in which the execution of the control program of the microcontroller can also control the filter capacitor to discharge the voltage and the transformer to prevent damage to th