| 摘要 |
PURPOSE:To decide the switching property, by measuring the voltage of a test current before and after electric conduction based on the charging current of a capacitor and calculating the switching loss from the difference voltage. CONSTITUTION:When the switch 2 is closed, the capacitor 4 is charged. When the charging is over, the switch 2 is opened to turn on the sample thyristor 7. Thus the electric charge of the capacitor 4 is discharged through the diode 11, reactor 6, sample thyristor 7 and current observing resistance 8 respectively. In the above- mentioned action, the charging voltage is measured V0 by a voltmeter 13 and in the initial mode, and then the voltage is measured V1 by a voltmeter 15 in the state under which the charging voltage of the capacitor 4 is inverted after a discharge with the switch 16 closed. Then the thyristor 7 is turned on after charging again the capacitor up to V0, and the voltage V2 is measured by the meter 15 after an inversion of the charging voltage. From the above-mentioned values, the loss of the thyristor 7 can be obtained from Pth=C[(V-V2)<2>-(V-V1)<2>]2. |
