Collaborate Disseminate
Here’s a question for you: when your PCB has a ground plane layer, where do return signals flow? It seems like a trick question, but as [Kristof Mulier] explains, there’s …read more Continue reading Proper Routing Makes for Many Happy Return Paths
Unable to account for the strange glitches he was seeing on his DIY CNC router, [Daniël Van Den Berg] wondered if his electronics might be suffering from some form of electromagnetic …read more Continue reading Simple Probe Sniffs Out EMI
Radio frequency electronics can seem like a black art even to those who intentionally delve into the field. But woe betide the poor soul who only incidentally has to deal with it, such as when seeking to minimize electromagnetic interference. This primer on how RF chokes work to reduce EMI …read more
Next time you get a new device and excitedly unwrap its little poly-wrapped power supply, remember this: for every switch-mode power supply you plug in, an amateur radio operator sheds a tear. A noisy, broadband, harmonic-laden tear.
The degree to which this fact disturbs you very much depends upon which …read more
Continue reading The RFI Hunter: Looking for Noise in All the Wrong Places
It’s one thing to know that your device is leaking electromagnetic interference (EMI), but if you really want to solve the problem, it might be helpful to know where the emissions are coming from. This heat-mapping EMI probe will answer that question, with style. It uses a webcam to record …read more
Continue reading Camera Sees Electromagnetic Interference Using an SDR and Machine Vision
[Gerald Musy] wanted to investigate the source of electromagnetic interference (EMI) in his switching power supply design. Stymied by the high cost of EMI probes, he decided to build his own. Lucky for us, he wrote up his results of experimenting with four different designs.
The probes include an unshielded loop, a shielded loop, a ferrite core probe, and an electric field probe. None of these are especially complex to build–the ferrite core one is probably the most involved–you can see from the scope traces that the different probes pick up different information.
Of course, once you identify where the …read more
