4. Result and Discussion
The typical high voltage switching signal measured by Tektronix oscilloscope is shown in Figure (4). The input signal from control unit via PIC16F84A generated 10 microseconds pulse (bottom signal in Figure (4)). After the high voltage supply is switched to ground, the voltage is raised again within 90 microseconds (upper signal of Fig. 4). In this experiment, the maximum supply of DC voltage was 4.5 kV. Figure 5 shows the switching signal at 4.36 kV with a time scale of 4 ns time/division. The voltage reached its ground level within 3.04 nanoseconds. The falling time of high voltage switching was measured using Tektronix high voltage probe and Tektronix oscilloscope 5 GHz sampling rate.