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3.4 Power Connection
3.4.1 AC Power Connection and Grounding Cable Connection
Plug one end of three-core power cord to the power socket on the ECG and the other end to the
socket on the wall as shown below:
3.4.2 DC Battery
The battery is not put into the battery compartment when it is dispatched with the machine, it needs
installation after receive it. After receiving the ECG, if built
‐
in rechargeable battery is to be used,
check the battery capacity and condition.
Connect one end of the grounding cable to the instrument’s potential equalization and connect
the other end to the ground. It can enhance the reliability of ground connection .It is forbidden to
use water pipe or other pipes as grounding cable. Otherwise, the first-class safety protection will fail
and patients may get electric shock.
3.5 Principle and Schematic Diagram
3.5.1 Principle
Multi-channel ECG is made up of amplifier circuit, print controller, keyboard controller, LCD
controller, CPU system and other parts. Lead signals from optical coupler are received by
CPU .After digital filter, sensitivity adjustment and print driver, then the signals are sent to print
controller for the waveform printing. When printing finished, the measurement and analysis will be
processed by the CPU system. Besides, the CPU system will receive the interrupt signal and button
codes to finish the interrupt processing. And CPU system will handle lead-off signal
，
no paper
detection
，
auto power off of batter voltage management, sampling and print of CRO simulation
output and EXT input. Keyboard controller produces scanning signals, finishes the key
anti-vibration, generate keypad number and interruption signals, which are processed by the CPU
system. LCD controller receives the data and orders from the CPU system and achieves the display
for the ECG control state.
Summary of Contents for EM-1203
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