晶体管测试仪m328_Vloss定义

xingjilang · 发表于 2023-7-14 09:01:56

本帖最后由 xingjilang 于 2023-7-14 16:59 编辑

不同材质电容的Q值和VLOSS有一定的对应关系。

Capacitor voltage loss (Vloss)Additionally a new parameter is output for capacitors with more than 5000 pF and low quality factor. This parameter is the voltage loss (Vloss) immediately after a load pulse. Some older paper capacitors make problems to get the right capacity. The error can be more than 100%. Also other instruments have problems to measure the right capacity for that capacitors. For type of capacitor a voltage loss of more than 10% is measured, so the Tester gives you a warning hint with the Vloss. VLOSS = Initial capacitor voltage loss due to the energy required to complete the switchover operation (see Figure 4).

Voltage loss after a load pulse, Vloss1[ With the measurement of capacitors with big capacity values the voltage loss after the loading is analysed. The reached load voltage is lost with electrolytic capacitors after a short periode. This voltage loss can be caused by a parallel connected resistor. But I assume, that this voltage loss of electrolytic capacitors is caused by a internal load dispersion directly after the load pulse. By loading the capacitors with the 470 kohm resistor, as it is done for little capacity values, this dispersion is already done after switching o the current. No voltage loss is detectable for this case. But if you load the same capacitor with a short current pulse, you can also detect the voltage loss for capacitors with lower capacity. The same e ect with lower loss can also be noticed for ceramic type capacitors.I have noticed, that capacitors with more than some % voltage loss are suspect. Especiallynoticable with respect to the voltage loss are older paper type capacitors, which are for other measurement a problem too. Some measurement examples will be shown in the following table.1 TransistorTester with AVR microcontroller and a little more Version 1.12k Karl-Heinz Kubbeleler

In this table you will find, that the capacity of all foil type capacitors can be measured by allintruments with good precision. The capacity values and the quality factor Q of the PeakTech LCR meter are minimum and maximum values of the measurements in the frequency range 100 Hz to 100 kHz . At all examples in the table the voltage loss Vloss of the TransistorTester is big, if the capacitors have a low quality factor. Only in this case the di erences of the capacity measurement results are also big. The TransistorTester can onlydetermine the voltage loss, if the measured capacity is more than 5000 pF.

以下百度翻译：
电容器电压损失（Vloss）此外，对于超过5000pF且质量因数较低的电容器，还输出了一个新参数。该参数是紧接在负载脉冲之后的电压损失（Vloss）。一些较旧的纸电容器在获得合适的容量方面遇到了问题。误差可能超过100%。此外，其他仪器在测量该电容器的正确容量方面也存在问题。对于电容器类型，测量到的电压损失超过10%，因此检测仪会用Vloss向您发出警告提示。VLOSS=由于完成切换操作所需的能量导致的初始电容器电压损失（见图4）。

负载脉冲之后的电压损失，V损失1[通过对大容量电容器的测量，分析了负载后的电压损失。电解电容器在短时间后会损失达到的负载电压。这种电压损失可能是由并联电阻器引起的。但我认为，电解电容器的这种电压损失是由负载脉冲后的内部负载分散直接引起的用470kohm电阻器加载电容器，就像对小容量值所做的那样，这种分散已经在切换电流后完成。在这种情况下，无法检测到电压损失。但是，如果你用短电流脉冲加载同一个电容器，你也可以检测到容量较低的电容器的电压损失。陶瓷型电容器也可以注意到损耗较低的相同效果。我注意到，电压损耗超过%的电容器是可疑的。关于电压损失，特别值得注意的是老式纸型电容器，这对于其他测量来说也是一个问题。一些测量示例将显示在下表中。1带有AVR微控制器和更多版本1.12k Karl Heinz Kubbeller的晶体管测试仪

在这张表中，你会发现，所有箔型电容器的容量都可以用全阻抗测量，精度很高。PeakTech LCR仪表的容量值和质量因数Q是在100 Hz至100 kHz频率范围内测量的最小值和最大值。在表中的所有示例中，如果电容器的品质因数较低，则晶体管测试仪的电压损失Vloss较大。只有在这种情况下，容量测量结果的差异也很大。晶体管测试仪只能在测量的容量大于5000 pF的情况下确定电压损失。