Patent ID: 6476618
Filing Date: 2002-11-05
Classification: H02H

Abstract:
A circuit for indicating abnormality of a three-mode surge absorber of a public electric power serially connected to an input and an output end of a public power supply, said input end having a line input end, a neutral input end, and a ground input end; said output end including a line output end, a neutral output end, and a ground output end for indicating abnormalities of a three-mode surge absorber f a public electric power completely; said circuit for indicating abnormality of a three-mode surge absorber of a public electric power comprising:a) a first two-end fuse having a first end coupled to said line input end; b) a first surge absorbing device coupled to a second end of the first two-end fuse and said neutral input end for absorbing a surge between said line input end and said neutral input end; c) a second surge absorbing device coupled to said line input end and said neutral end; d) an abnormal indication circuit coupled to said first surge absorbing device, said second surge absorbing device and said neutral input end for indicating abnormalities in three-mode of a public power supply wherein said abnormal indication circuit includes: i) a diode having an anode coupled to a line output end; ii) a first resistor having a first end coupled to a cathode of said diode; iii) a second resistor having a first end coupled to said second end of said first resistor and a second surge absorbing device; iv) a first transistor having a base coupled to said second end of said second resistor, and having an emitter coupled to said ground input end; v) a third resistor having a first end coupled to said cathode of said diode; vi) a fourth resistor having a first end coupled to said first resistor, a first end of said third resistor, and said cathode of said diode, and having a second end coupled to said collector of said first transistor; vii) a fifth resistor having a first end coupled to said second end of said fourth resistor and said collector of said first transistor; viii) a second transistor having a base coupled to said second end of said fifth resistor, and having a collector coupled to said second end of said third resistor; ix) a surge protection indicating having an anode coupled to said emitter of said second transistor, and having a cathode coupled to said neutral output end; and x) a Zener diode having a cathode coupled to said collector of said second transistor, and having an anode coupled to said neutral output end; and, e) a second two-end fuse having a first end coupled to said second surge absorbing device, and a second end coupled to said ground input end.