Universal telephone ringing generator

Abstract From the Canadian patent

Abstract of the Disclosure A high level signal generator provides a wide range of ringing signals in response to a periodic clock signal and as addressed by d plurality of manually setable binary words. The binary words are gated one after the other from a corresponding plurality of binary word sources in response to a control signal. An analog signal source generates an analog signal with a frequency as selected by an instant gated binary word. A control signal generator generates the control signal having a plurality of states, each corresponding to d one of a corresponding plurality of cadence phases. Each of the cadence phases is of a duration consistent with an occurrence of a …