
Theory of Operation
Chapter 3: Theory of Operation
Page 3 - 32
Advanta™ Bed Service Manual (man168ra)
The low-to-high transition of the inverted pulse at U4 pin 12 causes the start bit
to be clocked into the A/D as the first bit of the conversion instruction. The
remainder of the conversion instruction is sent by clocking in three more bits,
101, where 101 is the opcode for converting U4 CH 1 with respect to CH 0.
The next eight clocks at P131 pin 14 clock the eight bit A/D byte out of U4 pin
10 on the U4 pin 12 falling edge. The most significant bit (MSB) is clocked out
first, the least significant bit (LSB) last. If the voltage at CH 0 is greater than
Vcc/2, a second conversion is required. After clocking in the start bit as
described above, three more bits, 111, are clocked in, where 111 is the opcode
for converting U4 CH 0 with respect to CH 1. The next eight clocks at P131
pin 14 clock out the eight bit A/D byte as described above. C5 provides
decoupling.
Solenoid Drive
Connector P131, pins 7 - 12, routes the 24V, 50/60 Hz solenoid drive voltage
directly to the solenoid valves through P132 pins 13, 11, 8, 6, 4, and 2,
respectively. P132 pins 1, 3, 5, 7, 10, and 12 route the solenoid drive return to
P131 pins 21 - 24 through zero ohm resistor R99.
Grounds
Analog ground (Vss) and digital ground (GND) are tied together through zero
ohm resistor R29 to create a star ground configuration. This helps isolate noisy
digital return currents from the analog returns.
Capacitor C22 provides a path to chassis ground for chassis-referenced
transients on the circuit grounds.
Power Supply
Voltage regulator U8 maintains Vcc at 5 + 0.25 volts. C6 and C7 maintain
regulation stability. D2 provides a bleed off path for C6 during loss of power at
P131 pin 1 (VBB2SW). P131 pin 13 (CONN_CHK) returns Vcc to the control
processor board as an indication that the electrical connections between the
two circuits are made.
Resistors R14 and R16 voltage divides the unregulated supply VBB2SW by
0.263 to enable sampling by the A/D. Resistor R66 protects the A/D by current
limiting any transients on VBB2SW.
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...