Opus BT-C3400 v3.1 Sparks When Plugging In Power Adapter

[tfbit]

Just like the title says when I plug in the power adapter (plugged into charger) of my newly acquired Opus BT-c3400 v3.1 it sparks. I also found a video of the previous version sparking when the plugged in adapter is plugged into the charger. Is this some normal thing? Just wondering if I should go through the hassle to get it replaced since it seems to function normally. Here's the video:


https://www.youtube.com/watch?v=945tAc6FN3M


Thanks!

 

[ChrisGarrett]

Not uncommon. Something to do with in-rush current, I think?

Chris

 

[RetroTechie]

Yep. Likely due to an electrolytic capacitor (inside the Opus) charging up to its working voltage. And most likely, another capacitor (inside the wall brick) supplying that current.

Even smallish electrolytic capacitors can easily deliver 10's or 100's of amps :huh: - but only for a fraction of a second. Peak current mostly limited by wiring + contact resistance. High enough peak currents to cause sparks. But usually not much energy involved.

Haven't you ever noticed the same happens when you plug eg. a PC, monitor/TV, or a laptop AC adapter (or other beefy wall brick) into a wall outlet?