摘要 |
A protection circuit for telecommunications equipment powered remotely through a twisted pair subscriber loop, comprising: a charge storage circuit, coupled to the subscriber loop through an arm switch in parallel with an inrush resistor, for storing charge received from the subscriber loop, the charge storage circuit coupled to the telecommunications equipment for providing the charge thereto; a fault detection circuit for setting a first signal during a period of normal operation of the protection circuit and for resetting the first signal for a predetermined period during a fault; a processor adapted for setting an arm signal during the period of normal operation of the protection circuit; and, an AND logic circuit coupled to the arm switch, fault detection circuit, and processor for comparing the first and arm signals and for setting a third signal for opening and closing the arm switch.
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