Robert J Sims

US Patent:

40566870, Nov 1, 1977

Filed:

Aug 16, 1976

Appl. No.:

5/714592

Inventors:

Robert Dennis Sims - Addison IL

Assignee:

Western Electric Company - New York NY

International Classification:

H04M 322
H04B 346

US Classification:

179 16F

Abstract:

A common control circuit is disclosed for controlling bypassing relays to disconnect telephone line auxiliary circuits from their respective lines preparatory to line testing or for other desired purposes. The control circuit responds to a bypass request signal applied to a line by operating an associated bypassing relay and by activating a timing circuit. The timing circuit and other circuitry cooperate to hold the bypassing relay operated for a time interval sufficient for fulfilling the purpose of the bypass. For serving a bypass request received while another request is being served, the appropriate bypassing relay is operated when the subsequent request is received and the timing circuit is reactivated to insure a sufficient test time for the subsequent request. All operated bypassing relays are held operated until the expiration of a time interval during which no new bypass requests are received. The control circuit includes monitoring circuitry operative to detect selected internal and external failure conditions.