Circuit Description; Introduction; Digital Printed Circuit Assembly - Fluke MPS450 Service Manual

MPS450 SERVICE MANUAL

CIRCUIT DESCRIPTION

INTR ODUCTION
Refer to the Equipment-Relationship Illustration in Chapter 1, "General Information." As shown in the
illustration, the MPS450 comprises three printed circuit assemblies (PCAs), each portrayed as a
separate block on the diagram:
Digital Assembly
Analog Assembly
ECG Post Assembly
Each of these circuit blocks is described below. (See also the MPS450 PCA images, available in the
section called "Top-Level Assembly" in Chapter 6, "MPS450 Parts.")
D IG I TAL PR INT ED C IRCU I T A SS E MB LY
The Digital PCA is the location of the microcomputer that controls all instrument functions, as well as
general power supplies and digital circuits:
Power on/off control
o
Power supplies
o
± 5 V
MicroController:
o
Microprocessor
RAM
FLASH
EEROM
Timers
Serial ports
Keyboard Interface
o
Display interface
o
RS-232 port:
o
Level shifters
Transmitter/receivers
Digital/Analog PCA interface
Connectors:
o
External power-source connector
Internal power-source (battery) connector
Display connector
Digital/Analog PCA connector (controls patient-simulation circuits)
FUNCTIONAL DESCRIPTION
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