Chapter 3
Theory of Operation
REF 1029568 Rev B
BiPAP Focus Ventilator Service Manual © Respironics, Inc.
3-7
3.2.3
VGA Interface PCB
•
STN blue mode transmissive viewing
•
One-quarter VGA (320 x 240)
•
Dot pitch 0.36 x 0.36 mm
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Backlight inverter integrated
•
Real-time clock with battery backup
•
Microprocessor watchdog
3.2.4
VGA Display
•
STN blue mode transmissive viewing
•
One-quarter VGA (320 x 240)
•
Dot pitch 0.36 x 0.36 mm
3.2.5
External AC/DC Power Supply
•
90-240 VAC, 40-60 Hz input
•
120 W, 18 VDC output
•
3-wire, line cord connection, provides functional earth ground
3.2.6
Internal Battery
•
9.6 V, 3.7 Ah, nickel metal hydride (NiMH)
•
In-line thermal fuse
•
Built-in thermistor for temperature monitoring
•
Nominal charge time under 5 hours
•
Nominal run time 45 minutes at default settings