Telecom Cooling Redesign Project using 48V 4-Wire Fans
The challenge of this telecom cooling application was to maintain maximum fan speed control performance over an input voltage range of -33 to -72 VDC. Dual “boost” regulators were designed to ensure that the fans could maintain full speed capability when the supply voltage dropped below 48V. Dual passive filters were added to meet EMI regulatory requirements. Fan speed control based on temperature was implemented using a PWM control algorithm.
CRI’s electronic design and manufacturing facilities have the capability to provide complete custom fan speed control design for telecom cooling applications from prototype to production.
Telecom Cooling – Custom Fan Speed Control Specifications
- Supply Voltage: -33 to -72 VDC
- Fans: Four 48 VDC, 2.91A, 4-Wire Fans
- Dual “boost” regulators. Maximum peak fan current 7A per regulator, running fan current 5.5A per regulator at 75°C
- Fan Speed Control based on temperature from a remote thermistor
- Provides fan status based on monitoring fan tach pulses
- Open collector alarm outputs for fan failure and over temperature conditions
- Dual passive filters for EMI requirements
Additional Custom Fan Speed Control Designs for Telecom Cooling Applications
Telecom Cooling Fan Control using 48V Fans
FEATURES:
- Supply Voltage: -33 to -72 VDC
- Four 4-wire 48 VDC fans
- Dual “boost” regulators up to 5.5A per regulator
- Fan Control: PWM signal based on temperature
Telecom Cooling Fan Control using 24V Fans
FEATURES:
- Supply Voltage: -36 to -72 VDC
- Six 4-wire 24 VDC fans
- Dual “buck” regulators up to 5A per regulator
- Fan Control: PWM signal based on I2C command
Telecom Cooling Fan Control using 12V Fans
FEATURES:
- Supply Voltage: -36 to -72 VDC
- Six 4-wire 12 VDC fans
- Six individual 2A “buck” regulators for a total of 12A
- Fan Control: PWM signal based on remote command
Custom Fan Speed Control – Telecom Cooling Application
SmartFan® Design Group