Patent ID: 8027182
Filing Date: 2011-09-27
Classification: G01R

Abstract:
1. An electric current measurement apparatus for measuring an electric current value flowing to a desired electrode of an electron tube, comprising: a transformer having a primary winding of input side and a secondary winding of output side; a detection resistor connected in series in an ampere meter route of the desired electrode through which a measurement target electric current flows; a voltage detection unit which detects electric potential difference at the detection resistor and outputs pulse signals having pulse attribute corresponding to a detected value of the electric potential difference; a switching part connected between two wirings of the secondary winding of the transformer for providing a short circuit of the secondary winding according to the pulse signals outputted from the voltage detection unit; and a measurement current value output unit which measures pulse attribute of pulse-shape electric currents being induced on the primary winding of the transformer caused by intermittent short circuit of the secondary winding provided by the switching part, and outputs a value of the measurement target electric current flowing through the detection resistor based on a measurement result of the pulse attribute of the pulse-shape electric currents with referring to a predetermined relationship between a value of the electric current flowing through the detection resistor and the pulse attribute of the pulse signals generated in the voltage detection unit.