| 摘要 |
RF output level detector circuit. The RF output level detector circuit 1, applied particularly in collective TV antenna amplifying apparatus, comprises a block 4 of four comparator circuits 21 to 24 which activate three LEDs Dr, Dv, Da to signal the five possible output level states of the RF selector units 11 to 18, by means of a combination of one or two simultaneously-activated LEDs. The points of reference of the input of the comparators are situated at a DC voltage value representing the extreme values of the three ranges of useful level states. Once the adjustment process has been completed the detector circuit is deactivated by means of an electronic switch 6 and the units which are not used are deactivated by means of their corresponding manual switches. <IMAGE>
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