Smiths Graseby 3200, Техническое и сервисное руководство

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Smiths Medical International Ltd.
Issue 5 (August 2004)
3200 Service Manual 4 — 1
CHAPTER 4
CIRCUIT DESCRIPTIONS
This Chapter describes the action of the circuits that operate the 3200. It also shows the
associated circuit diagrams and circuit board layouts.
The 3200 contains six circuit boards as follows:
• Main.
• Regulator (power supply).
• Syringe size sensors.
• Status sensors.
• Distribution.
• Pressure sensing module.
Introduction
The overall block diagram for the 3200 is shown in Figure 4.1 .
The status sensor, syringe size sensor and the pressure sensing module boards provide a
mounting for the various sensors, and also junction points for the outputs of these boards,
thus enabling the outputs to be connected to other circuits.
Circuit descriptions
The block diagram for the Main board is shown in Figure 4.2 . It comprises the following sub-
circuits which are individually described in the sections that follow:
• Processor core.
• Motor interface.
• Power control.
• Sensors and pressure sensing interface.
• RS232 serial interface.
• Umbilical connector.
• Input/output interface.
Main board
The Processor core forms part of the Main board (see Figure 4.2 ). It is used to process all the
operating activities of the 3200.
The Processor core circuit is shown in Figure 4.3.
The microprocessor chip (IC14) has an on-board EEPROM which stores the programmed
settings. IC14 also incorporates an on-board RAM; an Analogue-to-Digital (A-to-D) converter;
timing circuitry; 4 pulse width modulated outputs; communications circuitry and an internal
watchdog.
Processor core