Patent · US Expired

Compact telephone line test apparatus

US4920555A · kind A · utility

10Cited by
5References
17Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 27, 1988
Grant dateApr 24, 1990
Priority date
Expiry dateSep 27, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M1/24
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A telephone line test apparatus is provided for determining the operational status of a telephone line. The apparatus has a cylindrical and compact housing structure, a light emitting diode, a resistor, an electrical interface, and an elongated cable with a terminal modular connector. The electrical interface is disposed within the housing structure and connects the light emitting diode and the resistor in series. The modular connector is communicatively connected to the electrical interface and flexible extends from the housing structure for easy and reliable use. The light emitting diode is a tri-state LED which indicates the presence of D.C. voltage and polarity, as well as A.C. voltage.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.