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Theory of Operation
Chapter 3: Theory of Operation
Page 3 - 22
Advanta™ Bed Service Manual (man168ra)
Patient Position Monitor (PPM)
Power is supplied to the Scale/PPM module via connector P5, by the P1600
central power supply. The power supply provides a pre-regulated 12-14V DC
referenced to signal VSS at 400mA maximum, 200mA typical, and another
unregulated 9-18V DC referenced to signal chassis digital ground at 200mA.
The voltage referenced to chassis digital ground is only used for the bed exit
ARMED signal that goes to the CIB. This is for field compatibility. The
supply with respect to signal VSS is distributed throughout the rest of the Scale
system/PPM from this assembly.
There is an on-board piezo speaker. The microprocessor allows it to turn on
with a logic level high to the base of a NPN transistor which sinks enough
current to turn the buzzer on. There are three output lines from the
microprocessor for three volume levels. This is achieved by placing multiple
resistor values in series with the piezo. A capacitor is connected across the
piezo to keep the voltage up when a resistor is used in series with the piezo.
The piezo is connected to 12 volt DC to achieve maximum decibel (db) level.
Steering diodes on the base of all three NPN keep the piezo attenuated when
the microprocessor is in a reset condition.
The Watch Dog Timer and Reset Circuit monitors VCC and when it comes up
to 4.75 volts, the reset line is released after a 250ms delay. The reset line goes
high if the strobe line is not strobed within 1.2 seconds. The inverse reset pin is
used to keep the piezo off when the controller is in reset.
Three Force Sensing Resistors (FSR) are located on the sleep surface. The
head sensor is the only one used for the position mode. Two FSR are located
in the thigh area and are used in the exiting mode as well as the head sensor.
Load beams are used to detect that a patient has left the bed. The FSR output
decreases in resistance with increased force. The PPM sensor (FSR) input
signal enters the board through P6, P7, and P8. Each sensor goes into one of
the four channels on the 8-bit A/D. The data is then read serially by the
embedded controller.
The inside (left) siderail LED is on whenever the PPM/bed exit system is on.
This lets the patient and caregiver know the system is on from the right side of
the bed. It is controlled by the microprocessor and switched via an NPN
transistor on P5.
The PPM caregiver interface, located on the outside of the left siderail is used
to initiate functions, mode selection and alarm volume level. The LEDs’
indicate status of the PPM/bed exit system.
Содержание Advanta P1600
Страница 2: ......
Страница 6: ...Revisions Page iv Advanta Bed Service Manual man168ra NOTES...
Страница 22: ...Chapter 1 Introduction Page 1 4 Advanta Bed Service Manual man168ra NOTES...
Страница 66: ...Warning and Caution Labels Chapter 1 Introduction Page 1 48 Advanta Bed Service Manual man168ra NOTES...
Страница 141: ...Chapter 3 Theory of Operation Advanta Bed Service Manual man168ra Page 3 3 3 LON Communication Error 3 45...
Страница 142: ...Chapter 3 Theory of Operation Page 3 4 Advanta Bed Service Manual man168ra NOTES...
Страница 190: ...Chapter 4 Removal Replacement and Adjustment Procedures Page 4 6 Advanta Bed Service Manual man168ra NOTES...
Страница 310: ...Warranty Chapter 5 Parts List Page 5 4 Advanta Bed Service Manual man168ra NOTES...
Страница 321: ...Weigh Frame Assembly Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 15 5 NOTES...
Страница 347: ...Right Head End Siderail Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 41 5 NOTES...
Страница 353: ...Footboard P1606 Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 47 5 NOTES...
Страница 357: ...Head and Foot Hilow Drive Assembly Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 51 5 NOTES...
Страница 361: ...Head Drive Screw Assembly Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 55 5 NOTES...
Страница 365: ...Knee Drive Screw Assembly Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 59 5 NOTES...
Страница 371: ...Power Module Chapter 5 Parts List Advanta Bed Service Manual man168ra Page 5 65 5 NOTES...
Страница 384: ...Permanent IV Rod P2221 Chapter 5 Parts List Page 5 78 Advanta Bed Service Manual man168ra NOTES...
Страница 386: ...Chapter 6 General Procedures Page 6 2 Advanta Bed Service Manual man168ra NOTES...
Страница 402: ...Tool and Supply Requirements Chapter 6 General Procedures Page 6 18 Advanta Bed Service Manual man168ra NOTES...
Страница 404: ...Chapter 7 Accessories Page 7 2 Advanta Bed Service Manual man168ra NOTES...
Страница 411: ...Schematic Wiring Diagram Scale Bed Exit Analog Board P N 4975102 FO 3 1 m168_101 Back to Chapter 3...
Страница 412: ...Schematic Wiring Diagram Patient Switch Board P N 67208 FO 3 2 m168a103 Back to Chapter 3...
Страница 413: ...Schematic Wiring Diagram J Box UTV Board P N 64935 FO 3 3 m168_107 Back to Chapter 3...
Страница 414: ...Schematic Wiring Diagram Footboard Scale Switch Display P N 63344 FO 3 4 m168_109 Back to Chapter 3...
Страница 415: ...Schematic Wiring Diagram Footboard Function Switch Footboard LED PN 63280 FO 3 5 m168_111 Back to Chapter 3...
Страница 416: ...Schematic Wiring Diagram ZoneAire Sleep Surface Switch Footboard LED Board P N 63276 FO 3 6 m168a113 Back to Chapter 3...
Страница 417: ...Schematic Wiring Diagram Logic Board PN 63285 FO 3 7 m168_115 Back to Chapter 3...
Страница 418: ...Schematic Wiring Diagram Power Board PN 63349 FO 3 8 m168_118 Back to Chapter 3...
Страница 419: ...Schematic Wiring Diagram Frame Interface Board PN 63352 FO 3 9 m168_120 Back to Chapter 3...
Страница 420: ...Schematic Wiring Diagram Scale Bed Exit Control Board P N 63217 FO 3 10 m168a123 Back to Chapter 3...
Страница 421: ...Schematic Wiring Diagram ZoneAire Sleep Surface Interface Board P N 6339601 FO 3 11 m168a126 Back to Chapter 3...
Страница 422: ...Schematic Wiring Diagram Sensor Board PN 4474001 FO 3 12 m168_128 Back to Chapter 3...
Страница 423: ...Schematic Wiring Diagram Air Control Board PN 44760 Sheet 1 of 2 FO 3 13 1 m168_147 Sheet 2 of 2 Back to Chapter 3...
Страница 424: ...Schematic Wiring Diagram Air Control Board PN 44760 Sheet 2 of 2 FO 3 13 2 m168_177 Sheet 1 of 2 Back to Chapter 3...
Страница 425: ...Schematic Wiring Diagram Head Sensor Assembly P N 63888 FO 3 14 m168a186 Back to Chapter 3...
Страница 426: ...Schematic Wiring Diagram Advanta Bed Wiring Diagram A model beds FO 3 15 m168a185 Back to Chapter 3...
Страница 427: ...Schematic Wiring Diagram HIlow Knee Sensor PN 63885 FO 3 16 m168_178 Back to Chapter 3...
Страница 428: ...Schematic Wiring Diagram Inner Patient II Board P N 67203 B model beds FO 3 17 m168a179 Back to Chapter 3...
Страница 429: ...Schematic Wiring Diagram Advanta Bed Wiring Diagram B model beds FO 3 18 m168a180 Back to Chapter 3...