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KX-FT931LA-B
[Surge Absorber Circuit]
This circuit is for absorbing surge voltage generated by the Q1.
[Control Circuit and Detecting Circuit]
The control circuit amplifies the output with increased voltage detected in the error detecting circuit. Then it drives the main transis-
tor.
In this power supply, the oscillation frequency(f) of the main transistor is defined by changing the output load.
This is shown as follows.
When the output voltage of the 24V circuit increases, the current of the photo coupler PC101 increases, the pulse width of the out-
put control circuit becomes higher and the ON period of Q101 becomes shorter.
[Over Current Limiter (O.C.L)]
The highest drain current (Q1) is limited by controlling f of Q1 of 24V. The 24V output is limited by this circuit.
[Over Voltage Circuit]
If the 24V output increases because the error detecting circuit or control circuit is broken, output becomes 0V by turning on the
zener diode D105.
Dummy load method (to quickly check the power supply output)
Refer to
Power Supply Board Section
(P.109).
Summary of Contents for KX-FT931LA-B
Page 11: ...11 KX FT931LA B 6 Technical Descriptions 6 1 Connection Diagram ...
Page 21: ...21 KX FT931LA B 6 4 2 Block Diagram ...
Page 23: ...23 KX FT931LA B ...
Page 66: ...66 KX FT931LA B ...
Page 67: ...67 KX FT931LA B CROSS REFERENCE Test Mode P 54 ...
Page 68: ...68 KX FT931LA B CROSS REFERENCE Test Mode P 54 ...
Page 69: ...69 KX FT931LA B CROSS REFERENCE Test Mode P 54 ...
Page 70: ...70 KX FT931LA B ...
Page 72: ...72 KX FT931LA B ...
Page 73: ...73 KX FT931LA B ...
Page 74: ...74 KX FT931LA B CROSS REFERENCE Test Mode P 54 ...
Page 101: ...101 KX FT931LA B NG Wave pattern Note Refer to NG Example P 106 ...
Page 103: ...103 KX FT931LA B I O and Pin No Diagram ...
Page 105: ...105 KX FT931LA B ...
Page 106: ...106 KX FT931LA B 12 5 5 3 NG Example ...
Page 110: ...110 KX FT931LA B 12 5 7 2 Troubleshooting Flow Chart ...
Page 115: ...115 KX FT931LA B 12 5 11 Thermal Head Section Refer to Thermal Head P 22 ...
Page 116: ...116 KX FT931LA B 13 Service Fixture Tools ...
Page 119: ...119 KX FT931LA B 14 2 Disassembly Procedurel 14 2 1 How to Remove the Operation Panel Block ...
Page 120: ...120 KX FT931LA B 14 2 2 How to Remove the Operation Board LCD and Platen Roller ...
Page 121: ...121 KX FT931LA B 14 2 3 How to Remove the Separation Holder and Document Feed Support ...
Page 122: ...122 KX FT931LA B 14 2 4 How to Remove the Image Sensor CIS and Feed Roller ...
Page 123: ...123 KX FT931LA B 14 2 5 How to Remove the Lock Lever and Thermal Head ...
Page 124: ...124 KX FT931LA B 14 2 6 How to Remove the Bottom Frame ...
Page 127: ...127 KX FT931LA B 14 2 10 Installation Position of the Lead Wires ...
Page 133: ...133 KX FT931LA B 15 2 3 Mechanical Movements in the Main Operations 15 2 3 1 Idle Status ...
Page 135: ...135 KX FT931LA B 15 2 3 4 Copying CROSS REFERENCE Sensor Section P 113 ...
Page 139: ...139 KX FT931LA B 16 1 4 Power Supply Board ...
Page 142: ...142 KX FT931LA B 16 3 Test Chart 16 3 1 ITU T No 1 Test Chart ...
Page 143: ...143 KX FT931LA B 16 3 2 ITU T No 2 Test Chart ...
Page 144: ...144 KX FT931LA B MEMO ...
Page 151: ...151 KX FT931LA B MEMO ...
Page 160: ...160 KX FT931LA B MEMO ...
Page 162: ...162 KX FT931LA B 20 1 2 Upper Cabinet Section ...
Page 163: ...163 KX FT931LA B 20 1 3 Lower Cabinet Section ...
Page 164: ...164 KX FT931LA B 20 1 4 Gear Block Section ...
Page 165: ...165 KX FT931LA B 20 1 5 Screws ...
Page 166: ...166 KX FT931LA B 20 1 6 Accessories and Packing Materials ...