Importance

Loading Importance Indicators...

Abstract

A sealing current generator for a telephone circuit provides a conventional nominal DC bias current in a telephone loop, and also temporarily provides a higher 'zap' current whenever the DC current path is broken and then reapplied to the telephone loop. During the 'zap' period, the voltage placed across the telephone loop is progressively increased in a number of predetermined steps if the current actually measured in the telephone loop fails to exceed a minimum value. The voltage is then maintained at its last level for the remainder of the 'zap' period, after which the device returns to its base mode of providing a nominal DC bias current to the telephone loop.

Loading the Abstract Image...

First Claim