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System Functional Descriptions
6-16
Battery/Power Functions
Refer to Figure 6-3 for the following descriptions.
Contacts/Battery Type
The battery mates with contacts on the Battery PCA. Power from the battery
flows through the Main Fuse on the Battery PCA, and then through separate
wires to the Power PCA for distribution to the rest of the unit.
The Battery PCA also detects whether the installed battery is a Philips
approved battery or not. It does this with a microswitch on the battery PCA,
which detects if a dimpled recess is present in the end face of the battery.
Philips M3516A/M5516A batteries have this dimple, while other batteries -
even those that are otherwise mechanically compatible - do not.
This information is passed via a separate pair of wires to the Power PCA and
from there to the Control PCA. During defibrillation, the Control PCA will
direct the Power PCA to charge the defibrillator capacitor more slowly if there
is a battery other than an M3516A present. This is done to reduce current
drain on the battery and thus avoid tripping the thermal cutout present on
many other batteries. Philips M3516A batteries do not have this cutout; so
their current delivery can be greater, allowing the defibrillator to charge more
quickly.
Charging
Power for charging the battery and running the unit can be supplied via the
Battery Charger Connector. This power can be from either an AC Power
Module (M3517A/M5517A) or a DC power Module (M3518A/M5518A).
Power flows directly from the Battery Charger Connector to the Battery PCA
via a separate wire pair. Instrument ground is connected to minus (-) of the
Power Module output.
Monitoring the battery and controlling the charging process are both handled
by the Power Module being used. The Power PCA receives status informa-
tion via connections both directly to the Power Connector and to the battery.
The Power PCA then sends this status information to the Control PCA via a
large ribbon cable. When the unit is powered on while the Power Module is
connected, the Power PCA instructs the Power Module to enter "power sup-
ply" mode.
The M3500B/M5500B uses approximately 250-400 uA of 12 V DC when
powered off to maintain configuration settings, system clock, etc. When pow-
ered on in Monitoring Mode, the unit consumes approximately 400-500 mA.
Theory of Operation
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