Huawei ATN 950B - Page 32

Figure 3-2 Block diagram for the working principle of the AND1FAN
Fans x 6
12 V power shut signals
12 V
Inter-board communication bus
Board in-position
module
PWM signals
Communication unit
module
CXP
Fan rotating speed signals
Fan in-position signals
12 V
12 V
12 V
Filter module
CXP
CXP
CXP
CXP
CombinerStart-delay
12 V
CXP
Intelligent fan speed
adjustment module
PWM driver
module
Fan speed
reporting module
Combiner/
soft-start module
Start-delay/Combiner Module
This module provides start delay to the combined two 12 V power supplies and protecting fans
against overcurrent.
Filter Module
This module filters the LC low frequency to enhance the EMC feature of the system.
Communication Unit Module
This module reports the board manufacturing information, PCB version, and environment
temperature information. In addition, this module provides 12 V power shut signals to the start-
delay module.
Intelligent Fan Speed Adjustment Module
This module reports information about the fan rotating speed to the AND1CXPA/
AND1CXPB and adjusts the fan rotating speed according to the pulse-width modulation (PWM)
signals received from the AND1CXPA/AND1CXPB.
Board In-Position Module
This module reports the board in-position signals to the AND1CXPA/AND1CXPB.
ATN 950B Multi-service Access Equipment
Hardware Description 3 Heat Dissipation System
Issue 03 (2012-07-23) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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