Phase Selection Power-Off Device for the Residual Voltage Testing
LI Lizhuo1, CAO Li2
1.Beijing Institute of Medical Device Testing, Beijing 101111, China;
2.Medical Electrical Equipment Room, Hunan Institute of Medical Device Testing, Changsha Hunan 410001, China
Abstract:The residual voltage testing is an important test project in electrical safety field. At present, the laboratory often used
the artificial simulation to pull out the device to operate the power off. However, we could not find the maximum residual voltage
value by this testing method and repeatability of measurement was poor. In order to solve these problems, a device which could be
cut off at any phase point during a period of alternating current was proposed. To achieve the precise power requirements, a variety
of methods were adopted, such as adopting the simulation of the circuit to detect the alternating current zero, using single chip
microcomputer to phase delay time and coordinating with mechanical relay for accurate power off during the process of developing.
The test results showed that the power failure accuracy of the device could reach ±0.3 ms. The repeatability of measurement was 7.5
times higher than the manual device. The maximum value of residual voltage can be easily found and the measurement stability can
be improved significantly by using this device and oscilloscope measurement.
李立焯1,曹俐2. 一种用于剩余电压测试的相位选择断电装置[J]. 中国医疗设备, 2018, 33(8): 46-49.
LI Lizhuo1, CAO Li2. Phase Selection Power-Off Device for the Residual Voltage Testing. China Medical Devices, 2018, 33(8): 46-49.