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12.6. Parallel Connection Detect Circuit
Function:
In order to disable call waiting and stutter tone functions when using telephones connected in parallel, it is necessary to have
a circuit that judges whether a telephone connected in parallel is in use or not. This circuit determines whether the telephone
connected in parallel is on hook or off hook by detecting changes in the T/R voltage.
Circuit Operation:
Parallel connection detection when on hook:
When on hook, the voltage is monitored at pin 86 of IC501. There is no parallel connection if the voltage is
1.65 V or higher, while a parallel connection is deemed to exist if the voltage is lower.
Parallel connection detection when off hook:
When off hook, the voltage is monitored at pin 90 of IC501; the presence/absence of a parallel connection is determined when
the voltage changes by 0.2 V or more.
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KX-TG5621BXS / KX-TGA561BXS
Summary of Contents for KX-TG5621BXS
Page 8: ...4 2 2 Handset 4 3 Displays 4 3 1 Display Items 8 KX TG5621BXS KX TGA561BXS ...
Page 9: ...4 3 2 Troubleshooting Handset LCD 9 KX TG5621BXS KX TGA561BXS ...
Page 12: ...4 4 2 2 Programming using the Direct Commands 12 KX TG5621BXS KX TGA561BXS ...
Page 14: ...4 5 Troubleshooting 14 KX TG5621BXS KX TGA561BXS ...
Page 15: ...15 KX TG5621BXS KX TGA561BXS ...
Page 18: ...6 HOW TO REPLACE THE HANDSET LCD 18 KX TG5621BXS KX TGA561BXS ...
Page 21: ...Note DSP is IC501 7 2 Check Battery Charge 21 KX TG5621BXS KX TGA561BXS ...
Page 27: ...7 4 5 RF DSP Interface Signal Wave Form Test Burst Mode 27 KX TG5621BXS KX TGA561BXS ...
Page 28: ... Test Burst Mode 28 KX TG5621BXS KX TGA561BXS ...
Page 71: ...21 EXPLANATION OF IC TERMINALS RF PART 21 1 IC701 71 KX TG5621BXS KX TGA561BXS ...
Page 72: ...21 2 IC801 Backside Terminal GND 72 KX TG5621BXS KX TGA561BXS ...
Page 73: ...21 3 IC851 Backside Terminal GND 73 KX TG5621BXS KX TGA561BXS ...
Page 78: ...24 CABINET AND ELECTRICAL PARTS BASE UNIT 78 KX TG5621BXS KX TGA561BXS ...
Page 80: ...26 ACCESSORIES AND PACKING MATERIALS 80 KX TG5621BXS KX TGA561BXS ...
Page 96: ...Memo 96 KX TG5621BXS KX TGA561BXS ...
Page 100: ...Memo KX TG5621BXS KX TGA561BXS 100 ...
Page 104: ...104 KX TG5621BXS KX TGA561BXS I N N KXTG5621BXS KXTGA561BXS ...