Patent ID: 6795531
Filing Date: 2004-09-21
Classification: H04M

Abstract:
An annunciator for use with a telephone set, said annunciator being adapted to play a recorded message as a response to an incoming call to the telephone set, said annunciator comprising:a voice ROM for storing said message and for producing an audio signal corresponding to said message when activated, a line current modulator coupled with said voice ROM and said telephone line, an on/off control circuit for said voice ROM for selectively turning said voice ROM on and off, a pair of input terminals for connection with the respective telephone wire pair of the telephone line, a start-up power supply including a storage capacitor coupled with said input terminals for storing a charge in response to a ring signal on the telephone line, a main power supply, an off-hook detector circuit powered by the start-up power supply and responsive to an off-hook signal from said telephone set for connecting the main power supply to the telephone line to receive power therefrom, a DTMF tone decoder coupled with said input terminals for decoding at least one DTMF code signal on said telephone line, a DTMF code signal detector coupled to said DTMF tone decoder and responsive to a selected one of the decoded DTMF code signals to provide a trigger signal to said on/off control circuit, said on/off control circuit being responsive to said trigger signal for turning on said voice ROM whereby the telephone line current is modulated by said line current modulator in accordance with the audio signal from said voice ROM.