Pulse Width Modulation
(PWM) Technology
Advanced Cooling Solutions Deliver Superior
Performance and Greater Efficiency
PWM Saves Energy and Extends the Life
of Delta Fans
Delta’s thermal technology continues to provide
better performance, high reliability and cost-effective
thermal cooling solutions. PWM is one of the primary
reasons Delta fans have a clear advantage over
other manufacturers.
Internal vs. External PWM Control
Delta’s internal PWM signal control fans deliver
a variety of advantages over external PWMcontrolled devices:
• Wide PWM frequency range input
(30Hz-30kHz)
• Lower vibration at lower duty cycle
• Prevent spike current on fan speed control
• Better motor efficiency
• Lower fan switching noise
The PWM Advantage
PWM regulates the voltage signal between fully on
and fully off, controlling the speed of a fan. The main
advantage is that power loss in the switching device
is very low. When a switch is off, there is practically no
current, and when it is on, there is almost no voltage
drop across the switch. Therefore, power loss is
close to zero.
PWM Control
Internal PWM Fan Curve vs. External PWM Fan Curve
4000
RPM
3500
Full
3000
RPM
2500
2000
1500
0
100%
Duty Cycle
1000
500
0
10
Duty cycle (%)
20
30
40
50
60
70
Blue: NEW DESIGN AFB0912VH-SP03 ( 4 wires)
Orange: External control AFB0912VH-F00
80
90
100
Wide PWM frequency range input (30Hz-30kHz) means lower vibration
and less noise.
Fan Speed Control Function
Vcc
Red Wire
Tach Signal Input
Control Chip
Blue Wire
(EX: ADT7463)
PWM Signal Output
Yellow Wire
Delta PWM
Control Fan
System
Black Wire
GND
Delta’s internal PWM signal control delivers a clear advantage over
external PWM controls.
The PWM function is commonly used in OEM cases. Delta also provides
standard PWM through distribution channels.
Selected PWM models are available from Delta. If you would like to
find out more, please contact your nearest distributor or contact us
at DCfansales@delta-corp.com.
4405 Cushing Parkway | Fremont, CA 94538
tel. 1.888.979.9889 | www.delta-americas.com
© 2011 Delta Products Corporation. All Rights Reserved. Delta PWM Technology - 08/11