Patent ID: 6128368
Filing Date: 2000-10-03
Classification: H04M

Abstract:
An apparatus for monitoring telecommunication transmission, comprising:a resistance detection unit for detecting a leakage current flowing therethrough and generating a leakage signal in response thereto, said resistance detection unit being connected between an input terminal of a transformer in a power supply at an absolute ground potential and a high voltage output terminal of the transformer at a relative ground potential, said resistance detection unit including:a. a plurality of resistors connected in series between the input terminal of the transformer at the absolute ground potential and the output terminal of the transformer at the relative ground potential for generating a voltage in response to the leakage current;b. at least one photo-coupler transistor connected in parallel with at least one of the plurality of resistors, said photo-coupler transistor being conductive when the leakage current flows through the plurality of resistors; andc. a logic gate connected to said photo-coupler transistor for generating the leakage signal when the photo-coupler transistor is conductive; anda central processing unit coupled to an output of the logic gate for shutting down the power supply in response to reception of the leakage signal.