Maquet Servo ventilator 900 C, Руководство по обслуживанию

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35
= Not valid for SV 900 E
Electronic unit – Monitoring
Description of block diagram
The text also refers to circuit diagrams.
Set O
2
alarm limits (PC board no 9)
The settings on the front panel knobs for O
2
CONC.
ALARM LIMITS are sensed in this block.
The output signal O
2
CONC. ALARM UNSET is a
digital signal (V15:10) which will be active (LO) if:
– the front panel knob LOWER ALARM LIMIT for O
2
CONC. is close to its left (counter clockwise) end
position (out of scale) and/or
– the front panel knob UPPER ALARM LIMIT for O
2
CONC. is close to its right (clockwise) end position (out
of scale).
This output signal (V15:10) activates the yellow lamp
SET O
2
ALARM on the front panel via the block ALARM
LAMP DRIVER.
The output signals furthered to the block O
2
CONC.
MONITORING correspond to:
– O
2
conc. lower limit
– O
2
conc. upper limit
– signal level corresponding to 18% O
2
(21% if R61 =
1 k Ω is in use).
O
2
conc. monitoring (PC board no 9)
The input signal is the O
2
CONC. from the amplifier for O
2
concentration. The scale factor is 50 mV/%.
The signal is compared with the preset alarm limits
from the block SET O
2
ALARM LIMITS. An alarm pulse is
generated to the ALARM LAMP DRIVER (for O
2
CONC.
ALARM) if the signal O
2
CONC. value is:
– less than the setting of the front panel knob
LOWER ALARM LIMIT for O
2
concentration or
– more than the setting of the front panel knob
UPPER ALARM LIMIT for O
2
concentration or
– below 18% independent of front panel setting
(21% if R61 = 1 k
Ω
is in use).
Set minute volume alarm limits
(PC board no 6)
The settings on the front panel knobs concerning ALARM
LIMITS for EXPIRED MINUTE VOLUME are sen sed in this
block.
The output signal is the signal MINUTE VOL. ALARM
UNSET (V10-L37&L38) which will be active (HI) if:
– the front panel knob LOWER ALARM LIMIT
for EXPIRED MINUTE VOLUME is close to its
left (counter clockwise) end position (out of scale)
and/or
– the front panel knob UPPER ALARM LIMIT for
EXPIRED MINUTE VOLUME is close to its right
(clock wise) position (out of scale).
The signal MINUTE VOL. ALARM UNSET activates a
flashing yellow light, SET MIN. VOL. ALARM on the front
panel via the block ALARM LAMP DRIVER.
Exp. minute volume monitoring
(PC board no 6)
The actual value EXP. MINUTE VOL. MONITOR from
the EXP. FLOW AVERAGER and the settings of the front
panel knobs concerning the ALARM LIMITS for EXPIR-
ED MINUTE VOLUME are sensed in the EXP. MINUTE
VOLUME MONITORING block.
The output (V9:7) is the signal EXP. MIN. VOL. LIMIT
EXCEEDED which will be active (HI) if the actual value of
EXP. MINUTE VOL. MONITOR is:
– more than the setting of the front panel knob
UPPER ALARM LIMIT for EXPIRED MINUTE
VOLUME.
– less than the setting of the front panel knob
LOWER ALARM LIMIT for EXPIRED MINUTE
VOLUME.
The signal EXP. MINUTE VOL. LIMIT EXCEEDED
acti vates a red flashing lamp, EXP. MINUTE VOLUME
ALARM, on the front panel and the AUDIBLE ALARM via
the block ALARM LAMP DRIVER.
Gas supply monitoring (PC board no 6)
The actual value of INSP. FLOW from INSP. FLOW LINE-
ARIZATION and the actual value of AIRWAY PRESSURE
(I) from AIRWAY PRESSURE (I) AMPLIFIER as well as
the control signal INSP. VALVE OPENED (LO) from END
POSITION PROTECTOR are sensed.
The output signal (V7:7) GAS SUPPLY FAILURE, will
be active during all modes except MAN. VENT. MODE if
the following occurs at the same time:
– INSP. FLOW is less than 0.3 l/second,
– AIRWAY PRESSURE (I), is less than 22 cm H
2
O and
– INSP. VALVE is fully open.
The signal GAS SUPPLY FAILURE activates the flash-
ing red alarm lamp, GAS SUPPLY ALARM, on the front
panel and the AUDIBLE ALARM via the block ALARM
LAMP DRIVER.