GE Dash 3000, Service Manual

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Revision A Dash 3000/4000 Patient Monitor 9-5
2000966-339
Assembly Drawings: Theory Of Operation
Power Supply
The subsystems within the monitor operate from a common 9 to 18 V
power bus. Due to the wide variety of voltages required by the various
subsystems, power is converted locally by each subsystem. This
architecture results in an efficient and compact system by reducing the
number of conversions required and optimizing the physical size of each
converter for the specific application.
When operating on AC mains power, the power bus voltage is 18 V,
generated by the offline switching power supply.
No AC mains power switch is provided.
The line voltage range switch must be set to select 115 V or 230 V (90 to
132 VAC or 190 to 264 VAC, respectively).
Data Acquisition System (DAS)
All interfaces to the patient occur through the DAS. The ECG function
uses a direct connection to the patient; therefore it is separately isolated
from the other functions (except respiration, which shares the ECG
patient interface) to substantially reduce coupling of noise and leakage
currents to/from other functions. All remaining DAS functions (i.e., pulse
oximetry, NBP, invasive pressure, temperature, cardiac output, and
CO
2
) share a common isolation barrier.
NOTE
The monitor supports two SPO2 configurations, GE SPO2 and
Masimo SET SPO2.