How to test the current on a motor?
Oscilloscope sensitivity is very high, there are tens of MV signal can be stable observation, if elected 5A out of 100mVThere are: 0.1V/5A=0.02 europe.For such a small resistance, the motor running state has little influence, if there is no instrument to do the measurement, you can take the current voltage method,Is to use a section of wire, through the 5A, and then measured the voltage =100mV at both ends of the wire, do not meet the change of wire length.
String into the known small resistance, take the resistance on the pressure drop, memory oscillograph to record the waveform, and then converted to the current value.If an electric current clamp is used, the current clamp is certainly possible, but it is necessary to understand the proportional relationship between the current clamp and the transmitted signal.Resistance sampling is simple and practical.
String into the pointer ammeter to see the impact value of the pointer (not very accurate)
