Covidien Puritan Bennett 700 Series, Руководство по обслуживанию

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Theory of operation
2-48 10070389 Rev. A Puritan Bennett™ 700 Series Ventilator System Service Manual
Figure 2-35. External battery
2.3.4 Pressure solenoid PCB
The pressure solenoid PCB contains these circuits:
• The pressure transducer/interface circuit includes pressure transducers and supporting
circuitry used to obtain pressure measurements throughout the ventilator. (See Figure
2-36 for pressure solenoid PCB and Figure 2-37 for pressure solenoid installed in
ventilator.) These onboard transducers monitor these pressures:
– Inspiration/atmospheric
– Exhalation
– Cylinder
– Exhalation flow sensor differential (two inputs) (This sensor uses as inputs pressures
from either side of a fine mesh screen in the exhalation system. The pressure
differential is directly proportional to the exhaled flow.)
In addition, the circuit interfaces an oxygen regulator pressure transducer, which is
located in the oxygen solenoid assembly, and an oxygen sensor, which is located in the
inspiration manifold.
• The solenoid drive circuitry switches and drives the solenoids within the ventilator.
• The audible alarm drive circuit sounds the ventilator’s main speaker alarm. A separate
secondary piezo alarm driver circuit provides redundancy if the main alarm fails.
• 2 Kbits of serial EEPROM store pressure transducer offsets and gains.
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