Microprocessor; 4-Way Solenoid Valve; Lcd Display; Audible Alarm - CAIRE Companion 5 Technical Manual

Microprocessor

The microprocessor is the only processing element of the CAIRE
Companion 5. It contains embedded software which is pro-
grammed with all of the parameters for alarm conditions and
settings of the concentrator. The microprocessor is directly respon-
sible for the following functions of the concentrator:
• Cycling (timing) of the 4-way solenoid valve
• Driving the LCD display
• Controlling the audible alarm
• Controlling the operational and warning LED lights
• Reading input from the OCSI sensor (OCSI models only)
The microprocessor is programmed with the alarm thresholds and
trigger points, as well as the timing of the 4-way solenoid valve
to cycle between sieve beds. A diagram of the input and output
of the microprocessor is shown below in Figure 5. Each input and
output is described further in the following sections.
Figure 5: Microprocessor Operation Block Diagram
Oxygen Concentrator

4-Way Solenoid Valve

The solenoid valve is connected to the circuit board's microproces-
sor by a 4-pin connector. The microprocessor is responsible for
sending the signal to open and close the valves. This cycles the air
through alternating sieve beds for the PSA process. The timing for
alternating the sieve beds is programmed into the microprocessor.

LCD Display

The 6-digit digital LCD display is mounted on the PCB and is vis-
ible on the front of the concentrator. Its purpose is to continually
count and display the hours that the concentrator has been in
operation and to display alarm conditions. The LCD display cannot
be re-set and displays time to the nearest tenth of an hour.

Audible Alarm

The CAIRE Companion 5 contains an audible buzzer that is sur-
face mounted on the PCB. Its purpose is to alert users of alarm
conditions. The microprocessor detects alarms by reading the
input from the OCSI sensor and the mains power switch. When
there is an alarm condition, the microprocessor sends a signal to
activate the audible alarm.

LED Lights

There are two (2) or three (3) (OCSI) LED lights that are surface
mounted on the PCB. They are visible from the front of the
concentrator and their purpose is to alert the user of operating
conditions or alarms.
The top LED indicator is green. It remains on at all times when the
power switch is in the "ON" (|) position and the electrical cord is
plugged in. A continuous green light indicates normal operation.
The next LED indicator will be red. This light will indicate mal-
functions with the device. When the microprocessor detects an
alarm condition from the power switch or the flow rate sensor, it
will send a signal for the red LED to illuminate. The red LED will
indicate a system malfunction, loss of power, or flow rate is out of
specifications.
The bottom LED indicator will be yellow (OCSI Models only). This
light will only indicate low oxygen concentration. This LED will
illuminate when the microprocessor detects an alarm condition
from the OCSI sensor. The LED will be solid if the oxygen concen-
tration is 70%-85%, and it will flash if the concentration is less
than 70%. The warning alarms section will describe these alarm
conditions in detail, and provide basic troubleshooting steps.
PN 14940837 B — 13