Compaq ProLiant 6500 Compaq ProLiant 7000 Server Technology - Page 15

Power Down Controls, Load Balancing, Power Factor Correction, Both Novell

Page 15 highlights

ECG078/0698 TECHNOLOGY BRIEF (cont.) ... Power Down Controls As shown in Figure 10, the server power switch connects to the microcontroller rather than directly to the power line. This means that turning off the power switch does not turn off power instantly. Instead, the microcontroller communicates with the system board and the OS by way of the I2C bus. The power down controls can be configured in one of three ways: • Secure Mode - Power supply will not shut down if power switch is flipped. • Delay Mode - Power supply will shut down after a 10-second delay. This allows time to reactivate the switch if it was mistakenly flipped. • Graceful Shut Down - A 10-second delay counter begins as a message warning of an imminent power-down goes to Compaq Insight Manager and the IMD. Because of the communication between the microcontroller and the OS, the OS can delay the power down until all running applications have properly closed. Should the OS not be running, the power goes down when the delay counter expires. The power down control feature is supported under Microsoft Windows NT 4.0. Both Novell and SCO are planning to implement the power down control in the future. Power Backplane Power Supply DC AC/DC AC Converter OS System Board I2C Bus Microcontroller Power Switch Power On Soft Power Down Figure 10: Power supply schematic. Load Balancing The power supplies automatically load balance to within 10 percent of the average current of all supplies. Before the power comes up, the master power supply matches its output load rails to those of the other power supplies so that the load is automatically balanced across all power supplies. If one supply fails, the load balancing feature allows the other supplies to pick up the remaining power load quickly. Power Factor Correction Compaq's intelligent power supplies have built-in power factor correction to synchronize the voltage and current phases. This ensures maximum power is available. It also reduces the return current in the ground line, which reduces the overall power consumption. 15

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T
ECHNOLOGY
B
RIEF
(cont.)
15
ECG078/0698
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Power Down Controls
As shown in Figure 10, the server power switch connects to the microcontroller rather than
directly to the power line.
This means that turning off the power switch does not turn off power
instantly.
Instead, the microcontroller communicates with the system board and the OS by way of
the I
2
C bus. The power down controls can be configured in one of three ways:
Secure Mode - Power supply will not shut down if power switch is flipped.
Delay Mode - Power supply will shut down after a 10-second delay.
This allows time to
reactivate the switch if it was mistakenly flipped.
Graceful Shut Down - A 10-second delay counter begins as a message warning of an
imminent power-down goes to Compaq Insight Manager and the IMD.
Because of the
communication between the microcontroller and the OS, the OS can delay the power down
until all running applications have properly closed.
Should the OS not be running, the power
goes down when the delay counter expires.
The power down control feature is supported under Microsoft Windows NT 4.0.
Both Novell and
SCO are planning to implement the power down control in the future.
System
Board
OS
Power
Backplane
Power Supply
AC/DC
Converter
AC
DC
Microcontroller
Power
Switch
Power On
Soft Power Down
I
2
C Bus
Figure 10: Power supply schematic.
Load Balancing
The power supplies automatically load balance to within 10 percent of the average current of all
supplies.
Before the power comes up, the master power supply matches its output load rails to
those of the other power supplies so that the load is automatically balanced across all power
supplies.
If one supply fails, the load balancing feature allows the other supplies to pick up the
remaining power load quickly.
Power Factor Correction
Compaq’s intelligent power supplies have built-in power factor correction to synchronize the
voltage and current phases.
This ensures maximum power is available.
It also reduces the return
current in the ground line, which reduces the overall power consumption.