| 主权项 |
1. A monitoring device comprising:
a first line section with a first connection point and a second connection point spaced apart from the first connection point in a direction of the line; a control unit; a first current sensing unit comprising: a first current source connectable to the first connection point via a first connecting line and connectable to the second connection point via a second connecting line, the first current source being configured to output a first current; a first switch having a control input, the first switch being inserted into the second connecting line and being configured to connect or disconnect the first current source to the second connection point; and a first differential amplifier having a first input, a second input, and an output, the first input being connectable to the first connection point via a third connecting line, the second input being connectable to the second connection point by a fourth connecting line; wherein the control unit is inserted between the output of the first differential amplifier and the control input of the first switch, wherein an actual current is passed through the first line section, wherein, in a first state, the first switch is closed and the first current is impressed on the first line section in addition to the first actual current and a first voltage determined by the amplitude of the actual current and the amplitude of the first current is present between the first input and second input of the first differential amplifier, wherein, in a second state, the first switch is open and a second voltage determined exclusively by the actual current is present between the first input and second input of the first differential amplifier, and wherein the control unit is configured to ascertain the amplitude of the actual current from the first and second voltage. |
