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Theory of Operation
Chapter 3: Theory of Operation
Advanta™ Bed Service Manual (man168ra)
Page 3 - 25
3
through R82, are used to configure the transformer’s primary coil for either
115V AC or 230V AC operation. Relay K1 acts as a supervisory switch for
solenoid power and logic power to the valve/sensor module. The relay is on
continuously during normal operation. It is turned off onlyif the cable is
disconnected, if a system failure is detected, or if the air system switch is
turned off.
The 4 amp triacs, Q3 - Q8 are driven by the opto-triac drivers U20 through
U25. Fuses F3 through F8 provide overcurrent protection for the cable and
valve/sensor module.
The circuitry surrounding U18 provides an O-ring feedback function to the
microprocessor. This circuit detects whether a triac is conducting. Resistors,
R50 through R55 are sized so that only when a triac is conducting will the U18
opto’s detector output switch. When a triac is conducting, the output of the
opto is a 50 or 60 Hz square wave. This square wave keeps capacitor C27
discharged so that the output of the Schmitt-Trigger Inverter is HI. When all
triacs are in the blocking state, C27 charges up via R66 and R69 which allows
the inverter output to go LO.
Compressor and Crossover Valve Drivers
The circuitry surrounding Q9, Q10, U26, and U27 makes up the compressor
and cross-over valve drivers. Q9 and Q10 are 800V, 8A, high noise immunity
triacs. The circuitry around U19 is another O-ring function similar to the one
previously mentioned.
Electrostatic Discharge (ESD) Protection
Some integrated circuits have a 100 ohm resistor in series with its Vcc pin to
limit Icc to 50 mA. This helps prevent latch-up. Switched inputs have RC
protection for debounce and static. Digital outputs have a 5.0v TVS zener, 1K
ohm resistor, and (Harris SP720) diode clamps.
LON Connector (P112, P113)
Pins 2 and 7 provide unregulated logic power to the board from the central
power supply.
Pins 3 and 8 are for unregulated logic power return.
Pins 4 and 5 are the Echelon net signal lines.
Pin 9 is the net shield connection.
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...