The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 24, 1976
Filed:
Aug. 01, 1975
Louis W Champan, Bellevue, WA (US);
Melco, Bellevue, WA (US);
Abstract
A test unit for testing the wiring connections in modular telephone installations. The unit consists of a housing with an input jack to receive the standard plug used to connect the telephone wiring to a handset. The jack has four terminals, one pair corresponding to the green and red(tip-ring) line wires, and the other pair corresponding to the yellow and black (ground and lamp a.c.) line wires. The tip-ring terminals are connected in the housing through a first diode, a Zener diode and a resistor to a 'tip-ring' L.E.D. The a.c. terminals are connected in the housing to a 'lamp' L.E.D. through a diode and a transistor, controlled by a network including a blocking capacitor. When the telephone line plug is inserted in the test unit jack, the 'tip-ring' L.E.D. will light only if the 'tip-ring' line voltage is correct in magnitude and polarity, and the tip ring line conductors have not been interchanged with the a.c. line conductors. The 'lamp' L.E.D. will light to indicate proper a.c. voltage on the a.c. line conductors. If the a.c. voltage is too low the 'lamp' L.E.D. will be dim. The 'lamp' L.E.D. will not light if the a.c. line conductors carry d.c. voltage.