18
KX-FT981LA-B / KX-FT987LA-B
6.3.5.
RTC Back up Circuit
1.
Function
This unit has a lithium battery (BAT1) which works for the Real Time Clock (RTC, Integrated into ASIC:IC1).
The RTC continues functioning, even when the power switch is OFF, backed up by a lithium battery.
2.
Circuit Operation
When the power is turned ON, power is supplied to RTC (IC1).
At this time, the voltage at pin 14 of RTC (IC1) is +3.3V. When the power is turned OFF, the battery supplies the power to RTC
through JS1, R30, D14. At that time, the voltage at pin 14 of IC1 are about +2.5V. When the power is OFF and the +5V and
+3.3V voltages decrease, the LOW is input to pin 114 of IC1. Pin 111 of IC1 outputs the reset signals. Pin 11 of IC1 become
low, then RTC (IC1) go into the back up mode, when the power consumption is lower.
Summary of Contents for KX-FT981LA-B
Page 11: ...11 KX FT981LA B KX FT987LA B 6 Technical Descriptions 6 1 Connection Diagram ...
Page 13: ...13 KX FT981LA B KX FT987LA B 6 2 1 General Block Diagram ...
Page 21: ...21 KX FT981LA B KX FT987LA B 6 4 2 Block Diagram ...
Page 23: ...23 KX FT981LA B KX FT987LA B ...
Page 63: ...63 KX FT981LA B KX FT987LA B 11 2 2 User Mode KX FT987 ...
Page 71: ...71 KX FT981LA B KX FT987LA B Countermeasure ...
Page 72: ...72 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 73: ...73 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 74: ...74 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 75: ...75 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 76: ...76 KX FT981LA B KX FT987LA B ...
Page 77: ...77 KX FT981LA B KX FT987LA B ...
Page 78: ...78 KX FT981LA B KX FT987LA B REFERENCE Test Mode P 54 ...
Page 82: ...82 KX FT981LA B KX FT987LA B ...
Page 108: ...108 KX FT981LA B KX FT987LA B NG Wave pattern Note Refer to NG Example P 113 ...
Page 110: ...110 KX FT981LA B KX FT987LA B I O and Pin No Diagram ...
Page 113: ...113 KX FT981LA B KX FT987LA B 12 5 6 2 NG Example ...
Page 115: ...115 KX FT981LA B KX FT987LA B ...
Page 120: ...120 KX FT981LA B KX FT987LA B 12 5 9 2 Troubleshooting Flow Chart ...
Page 126: ...126 KX FT981LA B KX FT987LA B 12 5 13 Thermal Head Section Refer to Thermal Head P 22 ...
Page 127: ...127 KX FT981LA B KX FT987LA B 13 Service Fixture Tools ...
Page 130: ...130 KX FT981LA B KX FT987LA B 14 1 2 How to Remove the Cutter Unit KX FT987 only ...
Page 131: ...131 KX FT981LA B KX FT987LA B 14 1 3 How to Remove the Lock Lever and Thermal Head ...
Page 133: ...133 KX FT981LA B KX FT987LA B 14 2 2 How to Remove the P C Boards and Power Cord ...
Page 136: ...136 KX FT981LA B KX FT987LA B 14 3 2 How to Remove the Operation Board LCD and Platen Roller ...
Page 137: ...137 KX FT981LA B KX FT987LA B 14 3 3 How to Remove the Separation Rubber Flap ...
Page 138: ...138 KX FT981LA B KX FT987LA B 14 4 Installation Position of the Lead Wires ...
Page 139: ...139 KX FT981LA B KX FT987LA B ...
Page 147: ...147 KX FT981LA B KX FT987LA B 15 2 3 4 Copying REFERENCE Sensor Section P 123 ...
Page 152: ...152 KX FT981LA B KX FT987LA B 16 1 4 Power Supply Board ...
Page 154: ...154 KX FT981LA B KX FT987LA B 16 3 Test Chart 16 3 1 ITU T No 1 Test Chart ...
Page 155: ...155 KX FT981LA B KX FT987LA B 16 3 2 ITU T No 2 Test Chart ...
Page 168: ...168 KX FT981LA B KX FT987LA B MEMO ...
Page 178: ...178 KX FT981LA B KX FT987LA B 20 1 1 Operation Panel Section KX FT981 ...
Page 179: ...179 KX FT981LA B KX FT987LA B 20 1 2 Operation Panel Section KX FT987 ...
Page 180: ...180 KX FT981LA B KX FT987LA B 20 1 3 Upper Cabinet Section ...
Page 181: ...181 KX FT981LA B KX FT987LA B 20 1 4 Lower Cabinet Section ...
Page 182: ...182 KX FT981LA B KX FT987LA B 20 1 5 Gear Block Section ...
Page 183: ...183 KX FT981LA B KX FT987LA B 20 1 6 Screws ...
Page 184: ...184 KX FT981LA B KX FT987LA B 20 1 7 Accessories and Packing Materials ...
Page 192: ...192 KX FT981LA B KX FT987LA B K N KXFT981LAB KXFT987LAB ...