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:
Apr. 03, 1979
Filed:
Dec. 12, 1977
Orrin B O'Dea, Garden Grove, CA (US);
Communication Mfg. Company, Long Beach, CA (US);
Abstract
Disclosed is a telephone system test apparatus for a telephone switching system having tip and ring circuits which cause a control relay to close upon completion of a path therebetween and which cause the same relay to close upon further opening and closures of the path between the tip and ring circuits. Means monitors such a telephone system for detecting a preselected operative condition therein. Means detects a predetermined impedance condition across such tip and ring circuits. A dial pulse loop circuit is coupled across such tip and ring circuits and it normally has a high impedance condition. Means selectively switches a first low impedance condition around the dial pulse loop circuit upon detection of such predetermined impedance condition and thereby applies a margin test to the first relay. Means opens and closes the dial pulse loop circuit one or more times for applying dial pulses across the tip and ring circuits upon detection of the proper operating conditions and the non busy condition. Means switches a second substantially lower impedance, than the first low impedance, around the dial pulse loop intermediate each opening of the dial pulse loop to thereby ensure proper operation of the control relay.