In March 2015 the ANSYS Advantage magazine (volume IX, issue 1) will contain an article on magnetic nanoparticle force computations written by John R. Brauer. The article contains material excerpted from Chapter 7 of Magnetic Actuators and Sensors, 2nd edition, as well as new enhanced color displays of magnetic fields and forces. The article will appear at www.ansys.com/magazine .

# September 17th Talk on Magnetic Forces

A talk will be given at 5:30 PM on September 17, 2014 by John Brauer. Its title is

MAGNETIC PARTICLE FORCES FOR ACTUATORS, RECYCLING SEPARATORS, AND BIOMEDICAL APPLICATIONS.

Magnetic volume force densities are computed using finite element analysis. Computations on small permeable particles are shown to agree with a classical formula for magnetic separators. Such forces are important for magnetic particle brakes and clutch actuators, and for recycling separators of steel waste. Computations are also made for biomolecular screening using magnetic beads such as those made by GE Healthcare.

This talk is based largely on parts of Chapters 5 and 7 of Dr. Brauer’s book *Magnetic Actuators and Sensors, 2 ^{nd} edition, *Wiley IEEE Press, 2014.

The talk is sponsored by the IEEE Magnetics Society Milwaukee Chapter and the IEEE Engineering in Medicine and Biology Society Milwaukee Chapter. It will take place at the Milwaukee School of Engineering, Todd Wehr Auditorium, 1025 N. Broadway, Milwaukee, WI 53202. Admission is free to all, and snacks will be provided.

# ERRATA for 2nd Edition Magnetic Actuators and Sensors

Page 22 Above (2.30) last sentence should be: Thus (2.29) becomes:

Page 36 Fig. 3.2 Second column should have *E=V/l*

Page 38 should have R* _{Fe}*= 1.5/[(2000)(12.57E-7)(.01)] = 59666 (E3.1.1)

Page 52 should have *W=*(0.125)^{2}/[2(12.57E-7)(0.1)(0.1)(1)] = 62.2 J (E4.2.2)

This energy of the reluctance method is about 56% lower than the 141.65 J

I thank Ashish Deshpande and K. C. Fung for pointing out the errors above. Feel free to email your comments, errors, or questions to me at jbrauer@ieee.org.

# MAY 15 TUTORIAL BASED ON 2ND EDITION OF Magnetic Actuators and Sensors, 2014

A tutorial paper will be presented the morning of May 15^{th} at the Electrical Manufacturing and Coil Winding Expo in Milwaukee, WI. Titled “Variations of Coils and Steel for Optimum Design of Magnetic Actuators,” the paper is authored by Mark Solveson and John Brauer. Based on the 2^{nd} edition of *Magnetic Actuators and Sensors *published in early 2014, the tutorial will last almost an hour. For complete seminars for your staff, contact the author at jbrauer@ieee.org.

# Magnetic Actuators and Sensors 2nd Edition Now Available

Wiley IEEE Press has now published the Second Edition of Magnetic Actuators and Sensors by John R. Brauer, copyright 2014. It is about 25 percent larger than the first edition (2006). Besides many updates and clarifications, it has new sections on topics including:

Mechatronics, analogous circuits, Halbach magnets, magnetic volume forces, magnetic bearings, magnetic separators, saturable magnetic infusion and effusion, encoders, current sensors, GMR spin valve sensors, Chattock coils, SQUID magnetometers, actuator systems for 2D planar motion, actuator design optimization, and digital hydraulic valves.

For more information see http://amazon.com/books or http://wiley.com .

# Paper to be presented in January 2014

“Magnetic diffusion delays in steel and permanent magnets when coil currents are turned on and off,” has been accepted for the Magnetics 2014 Conference, Orlando, FL, January 29-30, 2014. This new paper is partly based on the 2nd edition of Magnetic Actuators and Sensors by John R. Brauer, to be published by Wiley IEEE Press in late 2013.

# My papers published since my 2006 book

[161] “Style and technology of IAS technical papers,” *IEEE Industry Applications Magazine, *Jan./Feb. 2011, pp. 8-10.

[160] “History of the preparation and appearance of IEEE papers,” *IEEE Professional Communication Society Newsletter, *2009 Dec.-2010 May.

[159] “Considering electromagnetic delays,” *Motion System Design* magazine, Sept. 2009, pp. 24-27.

[158] “Modeling force density distributions on biomolecular nanoparticles undergoing magnetic separation,” *Magnetics Business & Technology*, 2008 Feb.-March, pp. 26-27.

[157] with D. L. Cook and T. E. Bray, “Finite element computation of magnetic force densities on permeable particles in magnetic separators,” *IEEE Trans. Magnetics*, vol. 43, no. 8, August 2007, pp. 3483-3487.

[156] “Magnetic diffusion times for infusion and effusion in nonlinear steel slabs and cylinders,” *IEEE Trans. Magnetics*, vol. 43, no. 7, July 2007, pp. 3181-3188*. To improve accuracy of (2) and (6) for t<0.3τ_{m}, replace their factor cos(nπx/w) by sin(nπ(½-x/w)).*

[155] “Toward the instant-on actuator,” *Machine Design*, July 27, 2006.

[154] “Finite element computation of magnetic diffusion times in nonlinear steel with surface field turned on and off,” *Proc. Applied Computational Electromagnetics Society Conf.*, Miami, FL, 2006 March.

# I am available to teach you about magnetic actuators and sensors

I teach an interactive seminar “Magnetic Actuators and Sensors” over the telephone and internet for your company or institution. The seminar can be tailored to your needs but usually consists of four sessions of three hours each. Only a college freshman’s understanding of basic math and physics is needed as a prerequisite. Watch introductory video at:

http://www.youtube.com/watch?v=VpQ22-B5oz8

or download or watch at: http://www.kickyoutube.com/watch?v=VpQ22-B5oz8

Video recorded 2008 June by Susan M. Brauer.

For further information, please email me at:

**John R. Brauer, Ph.D., P.E., Life Fellow IEEE**