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Operating Modes
Operating Modes
Operating Modes
Operating Modes
LP6 Plus, LP10, and LP20 Technical Manual
November 2000
Page 4-5
Page 4-5
Page 4-5
Page 4-5
AC power is available.
The AC power switch provides the disconnect of AC power, and the
mode switch on the ventilator front panel controls the operating
mode. With the AC power switch ON, the ventilator will operate on
AC power and will charge the batteries in all mode settings. With the
AC power switch OFF, the ventilator will operate on DC power and
will not charge the battery.
Power for the ventilator piston pump comes from six drive transis-
tors functioning as the motor commutator. The drive transistors’
current produces a magnetic field in the motor. This, in turn, causes
the motor to rotate under microprocessor control. Hall Effect sen-
sors detect the position of the rotor. The drive transistors then cause
the stator’s magnetic field to fluctuate, causing the 8-pole perma-
nent magnet rotor to follow that magnetic field. The fan (35) helps
dissipate motor generated heat.
Note
Schematic diagrams of the power/motor board, logic board, and
LED board are included in the back of this section.
Operating Modes
Operating Modes
Operating Modes
Operating Modes
Standby
Standby
Standby
Standby
The
MODE
MODE
MODE
MODE
switch in the Standby position applies AC power to the
unit, and provides battery charge voltage (13.8V on older models,
14.4V on newer models) to either the external battery or the internal
battery through the motor board. The battery charge mode is slower
than a standard charger, thereby an external charger is recom-
mended for the external battery. The battery charger has no prefer-
ence for either the internal or external battery. It simply chooses the
one having the lowest charge. When switching to a ventilation mode,
battery charge continues, functioning equally effectively in all
modes, whether the machine is running or not.
Assist/Control
Assist/Control
Assist/Control
Assist/Control
The system’s microprocessor reads the
MODE
MODE
MODE
MODE
and other switches 10
times a second and controls ventilator operation in accordance with
what it reads. With the
MODE
MODE
MODE
MODE
switch in Assist/Control, the micropro-
cessor initiates appropriate action only when it reads the switch
position and the interrelated controls, i.e.,
VOLUME, BREATHING RATE,
VOLUME, BREATHING RATE,
VOLUME, BREATHING RATE,
VOLUME, BREATHING RATE,
INSPIRATORY TIME, BREATHING EFFORT.
INSPIRATORY TIME, BREATHING EFFORT.
INSPIRATORY TIME, BREATHING EFFORT.
INSPIRATORY TIME, BREATHING EFFORT.
The patient’s breathing efforts control
rate as an assister. Flow is actually set by volume and I-time. Exha-
lation time is a function of rate and I-time.