4535 611 98931 iE33 Service Manual Page 72
CSIP Level 1 Theory of Operation: Physical Structure
Power
Subsystem
Power enters the iE33 system via the AC receptacle, located on the AC Tray. The AC Tray
includes an EMI filter, circuit breaker, OEM isolation transformer and OEM power relay. AC volt-
age is also routed to both custom power supplies (Acquisition and Platform). The Power Sub-
system (Figure 4-2) is controlled by the On/Standby switch, located next to the DVD drive. The
On/Standby switch, in conjunction with the Host Motherboard power control circuitry
(Figure 4-3), generates a PS_ON# signal, which activates the two system power supplies. The
power supplies are interlocked, which controls voltage application during power up.
The Acquisition and Platform supplies contain monitoring hardware, which prevent sustained
over- or under-voltage or over-current conditions. If one of the supplies does not meet specifica-
tion, the Power Subsystem shuts down. This condition requires the AC mains to be discon-
nected for at least one minute to discharge the power supply internal voltages and reset the fault
circuitry. There are no power supply adjustments. The power supplies are factory set and sealed.
When the Power Subsystem is in low-power sleep mode, the power supplies are shut down
except for +5STBY, which is required to support motherboard standby functions. When the sys-
tem is in standby mode (suspend-to-RAM), the Host software sets a battery enable register bit
on the AVIO-CAD Module and turns off both power supplies. In this state, the system is con-
suming less than 7 W of energy and stays in this state indefinitely while plugged into the AC
mains. The battery enable register bit allows the battery pack to provide energy to the Platform
Power Supply +5STBY circuit if the AC mains is disconnected.
The maximum duration of the mobile standby state is four hours. If the system is unplugged for
more than four hours and left in standby, a battery monitoring circuit senses the battery dis-
charge state and disconnects the battery from the Platform Power Supply, preventing battery
damage. By disconnecting the battery, the Platform Power Supply can no longer supply +5STBY
to both motherboards, and the system enters a complete power-down state. Subsequent iE33
power-up executes a cold boot cycle to obtain imaging operation. Normally, if the system is still
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