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System Control
System Control
System Control
System Control
LP6 Plus, LP10, and LP20 Technical Manual
November 2000
Page 4-13
Page 4-13
Page 4-13
Page 4-13
Alarm Lights; Front Panel Push Buttons
Alarm Lights; Front Panel Push Buttons
Alarm Lights; Front Panel Push Buttons
Alarm Lights; Front Panel Push Buttons
Alarm light signals are sent from the microprocessor to the LED dis-
play board by way of U2 on the older through-hole board, or U19 on
the newer surface-mount board. The
ALARM SILENCE
ALARM SILENCE
ALARM SILENCE
ALARM SILENCE
and
BATTERY TEST
BATTERY TEST
BATTERY TEST
BATTERY TEST
push button switches also come off of the display board and feed
into U4 on the older through-hole board, or U12 on the newer sur-
face-mount board. The microprocessor detects if these switches are
pressed individually, simultaneously, or in the case of
BATTERY TEST
BATTERY TEST
BATTERY TEST
BATTERY TEST
,
three times to initiate a graphic printout.
Error Detection
Error Detection
Error Detection
Error Detection
Normally, the circuit through resistor R12 on the older through-hole
board, or R41 on the newer surface-mount board, has a constant
high/low excursion. Should this excursion cease for a time period in
excess of 1/10th of a second, a microprocessor error has been
detected. If this occurs, motor movement will cease, all front-panel
LEDs will light, and a continuous tone alarm will sound.
Power/Motor Board
Power/Motor Board
Power/Motor Board
Power/Motor Board
Refer to the Power/Motor Board schematic at the end of this man-
ual. The basic function of the power/motor board is to control the
motor speed and position, and to provide power to the rest of the
ventilator.
All components outside the dotted line are external to the board.
This includes the power sources and associated circuitry, as well as
the motor end stroke sensor, exhale solenoid valve, and the fan
assembly.
The magnetic sensor senses the position of the piston and compares
it to constants stored in the EEPROM on the logic board. This allows
the microprocessor to know the location of the crank arm that
drives the piston. From there it counts the Hall Codes per revolu-
tion.
The circuitry on page 2 of the schematic is motor control circuitry.
Power transistors Q8 - Q13 on the older through-hole board, or Q6,
Q7, Q8, Q10, Q12, and Q14 on the newer surface-mount board,
supply power to the motor. These outputs are controlled by U10 on
the older through-hole board, or U4 on the newer surface-mount
board. Various address lines control the output, some from Hall
sensors and some from the microprocessor.
The microprocessor sends three signals:
•
Motor on or off
•
Motor forward, motor reverse
•
Solenoid