Packaging & Interconnects: PWM Fans For Thermal Cooling Minimize Power-Switching Noise

May 24, 2004

A new line of pulse-width-modulated (PWM) thermal-cooling fans performs at low noise levels by eliminating the power-switching noise of the fan, whose coils switch at 20 kHz. An external PWM signal controls fan speed. The fans ramp up linearly from a 20% duty cycle to the maximum rated speed. A soft-start circuit limits inrush currents during high duty cycles. These PWM fans are available in sizes of 70 by 15 mm, 70 by 25 mm, 80 by 25 mm, 92 by 25 mm, 120 by 25 mm, and 120 by 38 mm. Additionally, the PWM motor drive also is implemented in the company's 97- by 33-mm blower design. Prices range from $4 to $15 each, depending on fan size, features, and quantities ordered.

JMC Productswww.jmcproducts.com
(866) 776-3267

About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.