| 摘要 |
Disclosed is a system for supervising the level of input applied to a level regulator using a pilot signal. According to the invention, an input level supervisory circuit is provided which utilizes a level adjusting variable element of the level regulator, or employs a particular variable element arranged to be driven by means of the control voltage for said level adjusting variable element simultaneously with the latter element and having characteristics equal thereto, and which has a transmission ratio in a reciprocal or inverse relationship to the alternating current transmission ratio of a main signal alternating current transmission line of the level regulator. The input level supervisory circuit is supplied with an input voltage or current from a direct current constant-voltage power source or a direct current constant-current power source to generate an output voltage by means of which supervision of the level of the pilot signal input to the level regulator is performed. |
