Patent ID: 6115469
Filing Date: 2000-09-05
Classification: H04M

Abstract:
A circuit for providing a ring signal and DC power to a telephone line, comprising:a rectifier operative to convert AC power into DC power to be provided to the telephone line as a DC voltage and a DC current, the AC power having a substantially sinusoidal voltage component of a predetermined frequency substantially greater than the ring signal to be provided to the telephone line;a sampling circuit operative to sample the AC power at the frequency of a pulsed sampling signal, the sampled power being additively combined with the DC power from the rectifier to form a ring signal component of the power to be provided to the telephone line; anda control circuit operative to pulse the sampling signal at a first predetermined frequency when a ring signal is not to be provided to the telephone line and to pulse the sampling signal at a second predetermined frequency when the ring signal is to be provided to the telephone line, the second pulse frequency being different from the frequency of the AC voltage and current by the frequency of the ring signal, and the first pulse frequency being equal to the frequency of the AC voltage and current.