Mallinckrodt Nellcor N-20 Service Manual page 5

CONTENTS
Figure 9-15: Address Demultiplexing Circuit .................................................................................................... 9-15
Figure 9-16: Address Decoding Circuit .............................................................................................................. 9-16
Figure 9-17: CPU Memory Circuit ..................................................................................................................... 9-17
Figure 9-18: Input Port Circuit ........................................................................................................................... 9-18
Figure 9-20: Real-Time Clock Circuit ................................................................................................................ 9-19
Figure 9-21: Audio Output Circuit ..................................................................................................................... 9-20
Figure 9-6: Display Control Block Diagram ...................................................................................................... 9-20
Figure 9-23: User Controls Circuit ..................................................................................................................... 9-22
Figure 9-26: Analog Reference Voltage Circuit................................................................................................. 9-25
Figure 9-27: Ambient Light Circuit .................................................................................................................... 9-25
Figure 9-28: Ambient Temperature Circuit ....................................................................................................... 9-26
Figure 9-29: Battery Voltage Circuit .................................................................................................................. 9-26
Figure 9-30: Battery Type Circuit....................................................................................................................... 9-26
Figure 9-32: Printer Flex Circuit ........................................................................................................................ 9-28
Figure 9-8: LED Drive Circuit ........................................................................................................................... 9-30
Figure 9-9: Differential Synchronous Demodulation Circuit .......................................................................... 9-30
Figure 9-10 N-20 HSO Timing Diagram............................................................................................................ 9-30
Figure 9-13: AC Variable Gain Control Circuits .............................................................................................. 9-30
Figure 9-19: Output Port Circuit ........................................................................................................................ 9-30
Figure 9-22: Display Control Circuit .................................................................................................................. 9-30
Figure 9-24: Power Supply Circuit ..................................................................................................................... 9-30
Figure 9-25: Power Control Circuit.................................................................................................................... 9-30
Figure 9-31: Printer Interface Circuit ................................................................................................................ 9-30
Figure 9-33: N-20 SpO 2 Analog Block Diagram................................................................................................ 9-30
Figure 9-34: CPU Circuit..................................................................................................................................... 9-30
Figure 9-35: N-20 Main PCB Schematic Diagram............................................................................................. 9-30
Figure 9-36: N-20 Auxiliary PCB Schematic Diagram...................................................................................... 9-30
Figure 9-37: N-20 Flex Circuit Schematic Diagram .......................................................................................... 9-30
TABLES
Table 4-1: Microprocessor Error Codes............................................................................................................... 4-7
Table 8-1: Sensors................................................................................................................................................... 8-3
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