GE Medical Systems marquette Dash 2000, Service Manual, Page: 37 / 202

EQUIPMENT OVERVIEW: Theory of Operation
Revision A DASH 2000 Patient Monitor 2-15
2000 412-001
Components
Power Supply PCB The power supply PCB mounts internally to the monitor rear casting
assembly. ItÕs a 40 Watts controllable single output, universal input
switching power supply, which has been designed to meet the safety
ground leakage current requirements laid down by IEC 60601 and
UL 544.
Acquisition PCB
The acquisition PCB, or data acquisition system (DAS), located in the
monitor, is responsible for the acquisition of all vital-sign patient data.
Analog sensor/electrode input signals are amplified and conditioned by
hybrid assemblies, then converted to digital data. The digital patient
data is transferred across an isolation barrier via high-speed
opto-couplers to the main processor PCB for analysis and display.
The DAS consists of two isolated and one non-isolated sections which are
separated by a barrier that is capable of withstanding up to 6000 VDC
with respect to earth ground. Isolation is accomplished by using a
coupled inductor power supply and opto-isolation for signals crossing the
barrier.
Main Processor PCB The main processor PCB provides signal processing, system control, user
interface, and communications functions for the monitor, both color LCD
and monochrome LCD display versions. It receives and processes
digitized patient data from the isolated DAS assembly (acquisition PCB),
text and waveform information for the video display, interfaces with the
operator via the front panel switches and Trim Knob, and communicates
with other products on the network using a built-in Ethernet interface.
Main Connector PCB
The main connector PCB is connected to the main processor board and is
responsible for the dispersion of signals between the processor PCB and
the monitor rear panel connectors. Ethernet, AutoPort communication,
ECG/Defib syn and the docking station are the primary functions of the
board.