Siemens Servo Ventilator 300, Service Manual

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2
Servo Ventilator 300/300A Description of functions
E382 E380E 061 01 03 01 Siemens-Elema AB 63
8.7 Inspiratory solenoid with
position sensor
The gas flow through the
INSPIRATORY VALVE
UNIT
is regulated by the
INSPIRATORY SOLENOID
via the 8.6
NOZZLE UNIT
.
The solenoid receives power from the block
8.22
CURRENT POWER
. The current supplied to
the solenoid is regulated so that the
inspiratory valve unit will deliver a gas flow
according to the front panel settings.
An optical sensor on the board PC 1593
POSITION SENSOR I
mounted at the bottom of
the inspiratory solenoid detects its position
and the resulting
INSP
.
VALVE POSITION
signal is
used in the block 8.20
POSITION PD CONTROL
.
8.8 Valve code transponder
The inspiratory valve units are provided with
an electrical code that states the valve type
(AIR, O
2
, etc). This valve type information is
transmitted back via the 15
VALVE CONTROL
to
the 7.1
MIXER CPU
if required by the 7.1
MIXER
CPU
.
The
VALVE CODE TRANSPONDER
handles this
serial communication between the inspi-
ratory valve unit and the 7.1
MIXER CPU
.
8.9 Inspiratory valve key
The inspiratory valve units are provided with
a mechanical key,
INSPIRATORY VALVE KEY
, to
prevent that the inspiratory valve unit is
mounted in the wrong slot.
The valve key consists of a plastic guide
mounted underneath the inspiratory valve
unit and a corresponding guide mounted on
the pneumatic section base.
8.3 Inspiratory valve temperature
sensor
The temperature of the supplied gas is
measured by the
INSPIRATORY VALVE
TEMPERATURE SENSOR
. This sensor is a part of
PC 1637 and it is situated in the gas flow.
The output signal from this sensor is used in
8.13
DELTA PRESSURE AMPLIFIER
to compensate
for gas temperature variations.
8.4 Supply pressure transducer
The pressure of the supplied gas is
measured by the
SUPPLY PRESSURE TRANSDUCER
.
The output signal from this transducer is
amplified in 8.10
PRESSURE AMPLIFIER
and then
used in 8.11
PRESSURE CALCULATOR
to calculate
the absolute pressure of the gas.
8.5 Delta pressure transducer
and net
The gas flows through a net (resistance)
which causes a pressure drop. The pressure
is measured on both sides of this net and
the differential pressure value is then
amplified in 8.13
DELTA PRESSURE AMPLIFIER
.
8.6 Nozzle unit
The
NOZZLE UNIT
contains an O-ring and a
valve diaphragm. The valve diaphragm,
controlled by the 8.7
INSPIRATORY SOLENOID
,
regulates the gas flow through the
inspiratory valve unit.
Service interval 3000 h of operation for
exchange of the valve diaphragm and O-ring.
After replacement, allow the diaphragm to
settle during approx. 10 minutes before gas
pressure is connected to the inspiratory
valve unit.