# Visualizing Eddy Currents

If [Electroboom] gives up making videos and decides to become a lounge lizard in the Poconos, we hope he adopts the stage name Eddy Currents. However, he is talking about eddy currents in his recent video post that you can see below.

We know he doesn’t really think he can get the magnet to slow down with one sheet of aluminum foil and that he stages at least most of his little electric accidents, but we still enjoy watching it. Meanwhile, he also has a good explanation of why a copper pipe will slow down a magnet and how eddy current affects transformer efficiency.

His dancing coil demo is entertaining, but we hope you don’t try it yourself and we were very relieved when he brought out the isolation transformer. You might want to watch the video with a roll of aluminum foil and a magnet — that seems safe enough.

Understanding something of eddy currents explains a common superconductor trick, as well as induction cooktops, among other things. Of course, in motors and transformers these eddy currents are undesirable, and that fact influences the design of electromagnetic cores in those devices.

We like videos that entertain and those that teach something. [Electroboom] is always good for both. He does tend to bleep out some of his stronger language. This has led some viewers to automate their enjoyment of his predicaments.

## 18 thoughts on “Visualizing Eddy Currents”

1. Vikki says:

“I made a voltmeter that consumes 10 amps!” LOL

2. Scoldog says:

“Er, who,” said Arthur, “is Eddy, then, exactly, then?”

1. Lazy Maisy says:

Apparently he is the owner of a couch.

3. Doug says:

Respecfulle tat is poor titorial about eddy dvurrents

4. Doug says:

A fat as I know, a variac transformer,is not an isolation transformer.

1. dru says:

afaik, any transformer provides isolation. A variac is just a special transformer that lets you select how many windings on the secondary you want active. Isolation transformers have a 1:1 winding ratio; therefore they don’t do any transformation of voltage and only provide isolation.

1. Glenn says:

A variac is an autotransformer, so it doesn’t provide any isolation

2. nuclear says:

I’m with Doug. One of my variacs is NOT isolated. Be VERY careful with that.

3. He said it’s autotransformer variac, which does not provide isolation. However you have to understand, that electroboom physics are not realworld physics. Everything explodes all the time, you can touch everything without dying. It’s just for entertainment…

1. Doug says:

I based ny comment on what was contained in Al’s write up “His dancing coil demo is entertaining, but we hope you don’t try it yourself and we were very relieved when he brought out the isolation transformer.” At that point of the video an isolation transformer was brought out. Along with Bil, is a Hackaday contributor that generally does great job with technical writing. For the inexperienced, Al’s relief, could leave them to believe the Variac and similar tool provides a safety element.

5. Skeptical says:

Funny! Especially 0:58

1. seanmsiegel says:

Funny.. but good editing. Watch the second hand on the clock. Nearly 30 seconds passed before the arc ;)

6. Any thoughts on microwave oven transformer (MOT) core being welded?

1. f00barbob says:

After a little bit of research, it looks like it’s mainly for physical integrity due to the alignment of the core laminations (not interleaved, like in lower power types). Likely prevents buzzing/rattling/winding abrasion as the machine gets older.

7. steven says:

Please keep him out of the Poconos.
That’s a little too close for comfort.

8. Wretch says:

How has he managed not to kill himself on camera? (c:

9. Eddy? Come on! Why not “Steavie current”, “Frankie Current” or “spongebob squarepants” current? You just turned Nikola Tesla into just another forgotten imigrant with censored origins.

It is “induction current” as he called it and it will stay that way.

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