42
KX-FC265GR-T
6.8.
ITS (Integrated Telephone System) and Monitor Section
6.8.1.
Speakerphone Circuit
Function
This circuit controls the automatic switching of the transmitted and received signals, to and from the telephone line, when the
unit is used in the hands-free mode.
Circuit Operation
The speakerphone can only provide a one-way communication path.
In order words, it can either transmit an outgoing signal or receive an incoming signal at a given time, but cannot do both simul-
taneously. Therefore, a switching function is necessary to control the flow of the outgoing and incoming signals.
This switching function is contained in IC4 and consists of voice detector, TX attenuator, RX attenuator, comparator and attenu-
ator control. The function analyzes whether the TX (Transmit) or the RX (receiver) signal is louder, and then it processed the sig-
nal such that the louder signal is given precedence. The vice detector provides the attenuator control corresponding to the TX
signal. The comparator receives a TX and RX signals to the attenuator control corresponding to the RX signal. The attenuator
control provides a control signal to the TX and the RX attenuator to switch the appropriate signals ON and OFF. The attenuator
control also detects the level of the volume control to automatically adjust for changing ambient conditions.
Summary of Contents for KX-FC265GR-T
Page 13: ...13 KX FC265GR T 4 2 1 2 Error Messages Report 4 2 2 Cordless Handset ...
Page 22: ...22 KX FC265GR T 6 4 2 Block Diagram ...
Page 24: ...24 KX FC265GR T ...
Page 61: ...61 KX FC265GR T Note Refer to Program Mode Table P 102 ...
Page 69: ...69 KX FC265GR T 11 2 Cordless Handset ...
Page 72: ...72 KX FC265GR T 11 3 2 Service Mode Settings Note The above values are the default values ...
Page 80: ...80 KX FC265GR T Countermeasure ...
Page 81: ...81 KX FC265GR T REFERENCE Test Mode P 62 ...
Page 82: ...82 KX FC265GR T REFERENCE Test Mode P 62 ...
Page 83: ...83 KX FC265GR T REFERENCE Test Mode P 62 ...
Page 84: ...84 KX FC265GR T REFERENCE Test Mode P 62 ...
Page 85: ...85 KX FC265GR T ...
Page 86: ...86 KX FC265GR T REFERENCE Test Mode P 62 ...
Page 87: ...87 KX FC265GR T REFERENCE Test Mode P 62 ...
Page 91: ...91 KX FC265GR T ...
Page 116: ...116 KX FC265GR T ...
Page 123: ...123 KX FC265GR T I O and Pin No Diagram ...
Page 126: ...126 KX FC265GR T 12 5 5 2 NG Example ...
Page 130: ...130 KX FC265GR T 12 5 7 2 Troubleshooting Flow Chart ...
Page 136: ...136 KX FC265GR T 12 5 11 Thermal Head Section Note Refer to Thermal Head P 23 ...
Page 145: ...145 KX FC265GR T 13 Service Fixture Tools ...
Page 150: ...150 KX FC265GR T 14 3 Disassembly Procedure 14 3 1 How to Remove the Image Sensor CIS ...
Page 151: ...151 KX FC265GR T 14 3 2 How to Remove the Thermal Head ...
Page 152: ...152 KX FC265GR T ...
Page 153: ...153 KX FC265GR T 14 3 3 How to Remove the Bottom Frame ...
Page 154: ...154 KX FC265GR T 14 3 4 How to Remove the P C Boards and Speaker ...
Page 155: ...155 KX FC265GR T 14 3 5 How to Remove the Power Supply Board and AC Cord ...
Page 156: ...156 KX FC265GR T 14 3 6 How to Remove the Gear Block and Separation Roller ...
Page 157: ...157 KX FC265GR T 14 3 7 How to Remove the Gears Motors and Arms of the Gear Block ...
Page 158: ...158 KX FC265GR T ...
Page 159: ...159 KX FC265GR T 14 3 8 How to Remove the Charger Board A ...
Page 160: ...160 KX FC265GR T 14 3 9 How to Remove the Back Cover ...
Page 161: ...161 KX FC265GR T 14 3 10 How to Remove the Platen Roller and Lock Lever ...
Page 162: ...162 KX FC265GR T ...
Page 163: ...163 KX FC265GR T 14 3 11 How to Remove the Pickup Roller and Antenna ...
Page 164: ...164 KX FC265GR T 14 3 12 How to Remove the Operation Panel ...
Page 165: ...165 KX FC265GR T 14 3 13 How to Remove the Operation Board MIC Board and LCD ...
Page 166: ...166 KX FC265GR T 14 3 14 How to Remove the Separation Holder and Exit Roller ...
Page 167: ...167 KX FC265GR T 14 3 15 Installation Position of the Lead Wires 14 3 15 1 Lower Section ...
Page 168: ...168 KX FC265GR T ...
Page 169: ...169 KX FC265GR T ...
Page 170: ...170 KX FC265GR T ...
Page 171: ...171 KX FC265GR T 14 3 15 2 Operation Panel Section ...
Page 172: ...172 KX FC265GR T 14 3 15 3 Back Cover Section ...
Page 173: ...173 KX FC265GR T 14 3 16 How to Remove the Cordless Handset Board ...
Page 174: ...174 KX FC265GR T 14 3 16 1 How to Replace the LCD ...
Page 203: ...203 KX FC265GR T 17 1 7 Cordless Handset Board ...
Page 208: ...208 KX FC265GR T 17 4 Test Chart 17 4 1 ITU T No 1 Test Chart ...
Page 209: ...209 KX FC265GR T 17 4 2 ITU T No 2 Test Chart ...
Page 210: ...210 KX FC265GR T 17 4 3 Test Chart ...
Page 211: ...211 KX FC265GR T Memo ...
Page 224: ...224 KX FC265GR T Memo ...
Page 243: ...243 KX FC265GR T Memo ...
Page 261: ...261 KX FC265GR T Memo ...
Page 271: ...271 KX FC265GR T ...
Page 272: ...272 KX FC265GR T K T KXFC265GRT ...