Abstract: An automatic gain control circuit optimizes a follow-up performance of an automatic gain control loop to thus assure a good receiving operation. A generation timing or a generation period of a control signal GC is decided in response to a lapsed time in operation of the receiver device. For a predetermined rise period from a non-operated state to the steady operation state when a power supply is shifted from its OFF state to its ON state (power supply is turned ON) or at the time of intermittent receiving operation, the generation period of the control signal GC is set shorter than the generation period in a steady operation state so as to accelerate the response characteristic of the automatic gain control gain rather than the steady operation condition, and then switched to the generation period in the steady operation state after a predetermined time.

Abstract: An automatic gain control circuit optimizes a follow-up performance of an automatic gain control loop to thus assure a good receiving operation. A generation timing or a generation period of a control signal GC is decided in response to a lapsed time in operation of the receiver device. For a predetermined rise period from a non-operated state to the steady operation state when a power supply is shifted from its OFF state to its ON state (power supply is turned ON) or at the time of intermittent receiving operation, the generation period of the control signal GC is set shorter than the generation period in a steady operation state so as to accelerate the response characteristic of the automatic gain control gain rather than the steady operation condition, and then switched to the generation period in the steady operation state after a predetermined time.

Abstract: A telephone with a call-incoming-operation limiting function which has a clock means 2 for measuring the time and changes over call-incoming operation according to the time, comprises: a ringer-tone-volume controlling means 4 for controlling the tone volume of a ringer 5 during call incoming; and a call-incoming-operation limiting function controlling means 3 for instructing the ringer-tone-volume controlling means at the time set by a user to change over the tone volume of the ringer to a tone volume set by the user. By designating the time when the surroundings become quiet and by lowering the tone volume of the ringer, the user is able to know call incoming without imparting discomfort and annoyance to the surrounding people.

Abstract: An automatic gain controller has variable gain amplifiers (11a), (11b) for variably amplifying the input signals (RI1), (RI2) and a control loop that respectively performs automatic gain control of these variable gain amplifiers (11a), (11b) via feedback control of the output signal level. Variation amount in the detected output of the demodulated outputs (RD1), (RD2) is detected in the variation amount detector (20). The control section (19) selects the control loop where the output signal level is the highest when the variation amount is small and the system is in the stable state, and performs automatic gain control via a gain control signal in this control loop and correction gain control signals in the other control loops, and places in the non-operating state the gain control signal generator of the other control loops.

Abstract: An automatic gain controller has variable gain amplifiers (11a), (11b) for variably amplifying the input signals (RI1), (RI2) and a control loop that respectively performs automatic gain control of these variable gain amplifiers (11a), (11b) via feedback control of the output signal level. Variation amount in the detected output of the demodulated outputs (RD1), (RD2) is detected in the variation amount detector (20). The control section (19) selects the control loop where the output signal level is the highest when the variation amount is small and the system is in the stable state, and performs automatic gain control via a gain control signal in this control loop and correction gain control signals in the other control loops, and places in the non-operating state the gain control signal generator of the other control loops.

Abstract: An automatic gain control circuit having a plurality of receiving systems is structured to unify the receiving systems for performing level detection into one system and feedback data for controlling the gains of variable gain amplifiers 11a and 11b is subjected to correction of dispersion of the temperature characteristics between the variable gain amplifiers 11a and 11b of the receiving systems by operating a thermistor 31 so that a portion of an automatic gain control loop is made to be common without use of automatic gain control loops by the number corresponding to the number of the receiving systems.