Service manual

Servo Ventilator 300/300A Introduction
E382 E380E 061 01 03 01 Siemens-Elema AB 19
1
Expiratory feedback control system
17
The expiratory feedback control system
uses cascade control. It is active only during
expiration time in all modes. It applies
PRESSURE regulation.
•DESIRED VALUE is the PEEP LEVEL signal from
the PANEL SECTION (according to front panel
setting)
•ACTUAL VALUE is the EXP. PRESSURE signal
from the expiratory PRESSURE TRANSDUCER.
• The actuating signal from the PEEP PID
CONTROL
block is the POSITION REF. signal
used as DESIRED VALUE for the POSITION PD
CONTROL
.
•ACTUAL VALUE is the EXP. VALVE POSITION signal
from the POSITION SENSOR in the EXPIRATORY
VALVE
.
• The actuating signal from the POSITION PD
CONTROL
block is the EXP. VALVE CURRENT REF.
signal used as DESIRED VALUE for the CURRENT
CONTROL
& CURRENT POWER block.
• The ACTUAL CURRENT VALUE is an internal
feedback signal used in the CURRENT
CONTROL
block.
• The actuating signal from the output stage
of the CURRENT CONTROL & CURRENT POWER is a
pulse train with pulse width modulation
used to actuate the EXPIRATORY VALVE
SOLENOID
which generates a certain
opening of the EXPIRATORY VALVE.
POSITION
SENSOR
EXPIRATORY
VALVE
CONTROLLED SYSTEM
VALVE
SOLENOID
PRESSURE
TRANSDUCER
PEEP PID
CONTROL
CURRENT
CONTROL
&
CURRENT
POWER
POSITION PD
CONTROL
DESIRED EXPIRATORY
PRESSURE VALUE
EXP. VALVE
CURRENT REF.
PRESSURE CONTROL
ACTUAL POSITION VALUE
POSITION
REF.
ACTUAL
EXPIRATORY
PRESSURE
VALUE
PEEP LEVEL
EXP. VALVE POSITION
ACTUAL CURRENT VALUE
DESIRED
CURRENT
VALUE
DESIRED
POSITION
VALUE
EXP.
PRESSURE
300-A11E