Internal resistance of the high voltage module

High voltage module output resistance

 

01 High voltage module

---

I. Introduction

  Here is a high-voltage module that is often used in experiments. ·In fact, the original oscillator based on ZVS high-voltage package has been refitted. -The original self-excited oscillation is replaced by a newly added drive circuit. In this way, the primary oscillating AC voltage of the high voltage pack can be changed by changing the power supply voltage of the oscillation circuit, thereby changing the output of the high voltage pack. The high-voltage output is drawn out through two high-voltage insulated wires, and the high voltage is applied to the 108 ohm current sampling resistor to measure the output resistance of the high-voltage module.

2. Measurement results

1. Output voltage under no load

  Put the output of the high voltage module under no load, and measure the relationship between the operating voltage and the output high voltage. Using the straight line fitting method, a linear equation between the output high voltage and the working voltage is established. Here the linear fit parameters are given. The slope is 607, and the intercept is negative 22.6V.

▲ 图1.2.2 空载电压变化过程

  The relationship between operating voltage and output no-load voltage:

2. Measure the output current

  Next, add a 108 ohm resistor to the output port of the high voltage module as a current sampling resistor. By measuring the magnitude of the output current under different operating voltages, + in turn calculate the output resistance of the high voltage module. The no-load voltage under different operating voltages has been measured before, so the output resistance can be obtained by the ratio of the no-load voltage to the output current. This is the theoretical basis of the measurement. 
  Here, 200 data points are obtained when the operating voltage changes from 0V to 2V, where the yellow curve is the magnitude of the output current.

▲ 图1.2.2 设置电压与输出电流之间的关系

▲ 图1.2.3 设置电压与输出电流之间的关系

from headm import *
from tsmodule.tsstm32       import *
from tsmodule.tsvisa        import *

'''
setv, volt = tspload('OC', 'setv', 'volt')

for i in range(len(setv)):
    plt.clf()
    plt.plot(setv[:i+1], volt[:i+1], lw=3)

    plt.xlabel("Set Voltage(V)")
    plt.ylabel("High Voltage(V)")
    plt.grid(True)
    plt.tight_layout()
    plt.draw()
    plt.pause(0.001)
    pltgif.append(plt)
'''

setv = linspace(0, 2, 200)

dh1766volt(setv[0])
time.sleep(2)
volt = []
curr = []
R = 108

for v in setv:
    dh1766volt(v)
    time.sleep(2)

    meter = readmeter()
    volt.append(meter[0]*1000)
    curr.append(meter[1]/R*1000)

    plt.clf()
    plt.plot(setv[:len(volt)], volt, lw=3, label='Voltage(V)')
    plt.plot(setv[:len(volt)], curr, lw=3, label='Current(mA)')

    plt.xlabel("Set Voltage(V)")
    plt.ylabel("Current(mA)")
    plt.grid(True)
    plt.legend(loc='upper right')
    plt.tight_layout()
    plt.draw()
    plt.pause(0.001)
    pltgif.append(plt)

    tspsave('curr', setv=setv, volt=volt, curr=curr)

pltgif.save()
dh1766volt(0)
printf('\a')

plt.show()

  Next, according to the measured data, - to calculate the output resistance of the high-voltage module under different operating voltages. From the changing trend, the output resistance of the module is very high at the beginning, but when the operating voltage exceeds 0.25V, the output impedance drops below 400k ohms. The lower the operating voltage of the high-voltage module, the larger the output resistance. Here it shows that when the operating voltage exceeds 0.25V, the general change law of the output resistance.

▲ 图1.2.4 不同工作电压下的输出电阻

▲ 当工作电压超过 0.25V 之后的输出电阻

 

※ Summary  ※

---

  This article measures the output resistance of the high voltage module. Use an external resistor to measure the output current of the module. Divide the no-load voltage by the output current to obtain the output resistance of the module. The output resistance of the module varies with different operating voltages. = When the working voltage exceeds 0.25V, the corresponding output resistance is less than 400k ohms.

---

● Links to related diagrams:

• Figure 1.2.2 No-load voltage change process
• Figure 1.2.2 The relationship between setting voltage and output current
• Figure 1.2.3 The relationship between setting voltage and output current
• Figure 1.2.4 Output resistance under different operating voltages
• Output resistance when the operating voltage exceeds 0.25V