Importance

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Abstract

A privacy circuit for selective connection to a telephone line to provide for silencing of a preselected number of ringing signals before subsequent ringing signals are transmitted to a telephone to be heard by a user. The circuit derives power entirely from the ringing signal on the telephone line, counts the number of initial ringing signals and then actuates an electronic alternating-current switch when the preselected number of ring signals has been detected. A discharge circuit resets the device after ringing signals have ceased for a preselected time. The privacy circuit may also be used with its own annunciator rather than connected to a telephone.

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First Claim