| 摘要 |
This device comprises means 1 capable of sensing an electromagnetic signal which is radiated by a television receiver 2 during operation and whose frequency has a first or a second value depending on whether the television receiver is or is not receiving a television transmission, and which are capable of producing in response to the said signal an output signal having a first or a second amplitude depending on whether the frequency of the signal received by the sensor means has the first or the second value, respectively, a threshold circuit 3 which takes a first or a second state depending on whether the output signal from the sensor means has the first or the second amplitude, respectively, and means 4 for controlling the interruption of the current supply to the receiver 2 when the threshold circuit is in the second state. <IMAGE>
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