Patent ID: 6054865
Filing Date: 2000-04-25
Classification: G01R

Abstract:
A safety compliance test instrument, comprising:a high voltage DC hipot test circuit arranged to output an adjustable DC voltage having a maximum amplitude of at least 1000 volts and of measuring leakage current to ground in a device to which the high voltage is applied in order to perform a hipot test;a high voltage AC hipot test circuit arranged to output an adjustable AC voltage having a maximum amplitude of at least 1000 volts and of measuring leakage current to ground in the device to which the high voltage is applied;an insulation resistance test circuit arranged to output a DC voltage of between 100 and 1000 volts and apply it to a device in order to perform an insulation resistance test on the device and display an equivalent resistance of the device; anda current supply circuit arranged to output a low voltage AC current in order to perform tests of a ground circuit of the device,wherein the DC hipot, AC hipot, insulation resistance, and current supply circuits share a common power supply, control circuit, and user interface andwherein the common power circuit for the instrument includes:a potential transformer arranged to convert input line power to a low voltage sinusoidal waveform;a rectifier arranged to convert the low voltage sinusoidal waveform output by the potential transformer into a low voltage DC signal;a multistage amplifier arranged to be controlled by the control circuit to convert the low voltage DC signal into a low voltage, high current output signal;a voltage amplifying transformer arranged to convert the low voltage, high current signal output by the multistage amplifier into a high voltage AC output for use in an AC hipot test; anda high voltage rectifying circuit arranged to convert the high voltage AC output into a DC voltage for use in the DC hipot and insulation resistance tests.