Service manual

2
Servo Ventilator 300/300A Description of functions
E382 E380E 061 01 03 01 Siemens-Elema AB 65
8.15 Flow calculator
The flow depending signal from 8.13 DELTA
PRESSURE
AMPLIFIER and the absolute supply
pressure depending signal from 8.11
PRESSURE CALCULATOR are used to generate a
linearized actual gas flow signal (AIR FLOW).
This flow signal is a flow measurement
referenced to standard barometric pressure
(1013 mbar, 760 mm Hg). For conversion to
ambient pressure, see section "Conversion
for flow and volume to achieve reference to
ambient pressure" in the Operating Manual.
8.16 Flow I control
Controller block comparing actual AIR FLOW
and desired AIR FLOW REF. The actuating
output signal is used to influence the block
8.17 COMPENSATION ±5%.
8.17 Compensation ±5%
The output signal corresponds to the input
signal AIR FLOW REF with an adjustment
controlled by the block 8.16 FLOW I CONTROL.
The adjustment (compensation) is limited to
a maximum of 5%.
8.18 Valve position calculator
This function is an additional compensating
element for the regulation where the actual
absolute supply pressure value from the
block 8.11 PRESSURE CALCULATOR and the
desired AIR FLOW REF signal compensated in
the block 8.17 COMPENSATION ±5% generate
an activating signal which is used as a basic
reference for POSITION of the inspiratory valve.
8.19 Flow PI control
Controller block comparing actual AIR FLOW
from the block 8.15 FLOW CALCULATOR with
desired AIR FLOW REF signal compensated in
the block 8.17 COMPENSATION ±5%. The
actuating output signal is added as a final
adjustment to the basic position signal from
the block 8.18 VALVE POSITION CALCULATOR
generating the desired POSITION REF signal for
the block 8.20 POSITION PD CONTROL.
8.20 Position PD control
Controller block comparing actual INSP. VALVE
POS
. value from the position sensor in the
block 8.7 INSPIRATORY SOLENOID WITH POSITION
SENSOR
and desired POSITION REF signal
mentioned in the block 8.19 FLOW PI CONTROL.
The actuating output signal (together with a
signal compensating for the supply
pressure) is used as the desired INSP. VALVE
CURRENT
REF signal in the block 8.21 CURRENT
CONTROL
.
8.21 Current control
Consists of the board PC 1585 CURRENT
CONTROL
.
Controller block regulating the current going
to the block 8.7 INSPIRATORY SOLENOID WITH
POSITION
SENSOR according to the desired input
signal IINSP. VALVE CURRENT REF from the block
8.20 POSITION PD CONTROL. The actuating
output signal is a pulse train with constant
frequency of 30 kHz and pulse width
modulation used in the block 8.22 CURRENT
POWER
.