Motors follow the path of less reluctance to rotate. Thus, you need timing of applied power to get them moving. Part 1 and Part 2 of this FAQ looked at brushed and brushless DC motors, permanent-magnet and wound-rotor synchronous motors, and induction motors. These motors all have drawbacks, including mechanical wear of commutators, slip rings […]
EMI/EMC/RFI
How to use RF current probes for EMI: Part 2
In Part 2, you will learn how to use an RF current probe to calculate E-fields and troubleshoot EMI emissions from cables. Free and low-cost software tools let you customize the calculations based on your current probe’s data. As I mentioned in Part 1, RF current probes are one of my most useful troubleshooting tools. […]
How to use RF current probes for EMI: Part 1
DIY and commercial RF current probes let you find which cables act as EMI-emitting antennas. RF current probes are one of my most useful troubleshooting tools. Because most radiated emissions failures are due to attached cables acting as transmitting antennas, clamping an RF current probe around a wire or cable will measure the common mode […]
EMC summit gives engineers tips and fundamentals
An IEEE EMC Society chapter provided training on FCC Part 15, shielding effectiveness, and EMC art & science. Boxborough, Mass — Interference among electronic devices never goes away. Engineers who aren’t EMC experts seem to need constant introductions and reminders of how to reduce interference because every design is different. EMI/EMC issues keep popping up, […]
How do I choose an electric motor, and how do I test it? part 2
Learn the basics of back EMF, how to measure it, and the advantages and disadvantages of different motor types. In Part 1 of this FAQ, we looked at brushed DC and brushless DC (BLDC) motors, with the latter having some similarities to a permanent-magnet synchronous motor (PMSM). The simplified PMSM diagram in Figure 1 resembles […]
How to choose and test an electric motor: part 1
Motors bridge electronics with electromechanical devices. To learn how to test motors and their electronics, you should first understand how motors work. Electric motors are ubiquitous, appearing in everything from electric toothbrushes to electric locomotives. There are, however, seemingly almost as many motor types and configurations as there are applications, which makes choosing and testing […]
How to locate EMI emissions with near-field probes: Part 3
Part 3 of a series on using near-field probes for detecting EMI sources shows you how to set up a spectrum analyzer and how to detect emissions problems. Now that we’ve discussed the theory of measuring near-field emissions (Part 1) and how to use near-field probes (Part 2) to make the measurements let’s discuss how to […]
How to locate EMI emissions with near-field probes: Part 2
Now that you know a little theory of near-field measurements, how do you use near-field probes and a spectrum analyzer to help you troubleshoot and mitigate emissions issues? Remember, as mentioned in Part 1, that deciding whether to use an H-field or E-field probe depends on whether you’ll be probing high switching currents — di/dt […]
How to locate EMI emissions with near-field probes: Part 1
Near-field probes let you find the sources of near-field and far-field EMI that ruin your design, and your day. You don’t need to know Maxwell’s Equations to troubleshoot your designs.
IEEE EMC Symposium 2023: Presentations
Long known for its academic papers and presentations, the EMC+SIPI Symposium in 2023 featured more practical tutorials and workshops than ever before. See photos from the technical sessions and workshops.
