LIFEPAK 15 Monitor/Defibrillator
Service Manual
Device Description
Functional Descriptions
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When the device is OFF, closure of the device power control activates A03 Power PCB circuitry to alert the power processor, which
chooses the appropriate source to originate SW_VB (switched battery voltage) power. SW_VB is then routed, in turn, to the A04
Therapy PCB and A01 System PCB for use, as is, and for further processing into system power supply voltages.
Closure of the power control when the device is ON triggers an orderly device shutdown prior to turning off SW_VB.
Therapy PCB (A04)
The A04 Therapy PCB maintains the patient interface for therapeutic purposes. In addition to developing defibrillation and
noninvasive pacing energies, the A04 Therapy PCB ensures safe delivery of those energies, captures ECG paddles, and monitors
attachment of the QUIK-COMBO electrodes.
The major subsystems of the A04 Therapy PCB and their basic functions are as follows:
Defibrillator processor
The defibrillator processor manages the defibrillator energy storage and delivery functions using serial inputs from the A01
System PCB ASIC, hardware inputs from external paddles, and inputs from other A04 Therapy PCB circuitry. Status of the
defibrillator subsystem is reported serially to the A01 System PCB ASIC.
Energy storage capacitor charger (ESCC)
Under control of the defibrillator processor, the ESCC converts COM_VB (common battery voltage) to high voltage for
application to the energy storage capacitor. Circuitry within the ESCC performs comparisons between stored energy and
target energy to limit charging to the value selected by the user. Additional circuits compensate the ESCC for low battery
voltage, provide over-voltage protection, and send divided capacitor high voltages to separate safety monitoring and energy
display circuits.
Transfer relay control
To enable the transfer of defibrillation energy, the A04 Therapy PCB integrates control signals from the
SHOCK
button (or
external paddles’
SHOCK
buttons), defibrillator processor, ESCC, and the A01 System PCB ASIC. The transfer relay will be
activated only to deliver energy to the defibrillation electrodes when all conditions are satisfied in each system component.