A loop-circuit for a telephone line is provided that includes a transistor having a first electrode directly connected to one of the wires of the line, a second electrode connected to the other of the wires of the line by means of a resistor, a gate electrode thereof being connected via a resistor to one of the wires of the line, and by means of a capacitor to the other wire of the line, wherein a switch is arranged to cut-off the transistor and another switch is arranged or provided to disconnect one of the plates of the capacitor from the rest of the circuit.
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