And now for something completely different.

[scottrod]

In our application we take data in aircraft during flight. A situation occurred where we had 56 VDC with essentially unlimited amps jump onto the daq ground system. When this occurred, the card instantly welded itself to the adapter at the ground locations. It won't come apart! Lots of other smoking wires as well, it was a mess with lots of excitement for a minute or so.

Crazily enough, it still works! Does it need to be recalibrated? 🙂

[Henrik_Volkers]

Thanks for sharing such a picture.

ReCal for shure since it had been used clearly out of spec (even if MAX CURRENT over GND/housing is not found in the datasheet. 😄

Calibration nearly expired anyway ...  😉  

Without looking at the PCB you don't know if a GND line went hot and maybe into higher impedance resulting in increased noise, drift, temperature sensitivity ..   inspecting buried traces in a multilayer PCB?

But the housing is 'well' welded now 😄

Fire in a flying aircraft ... OMG

Who qualified the power supply ?   Isn't graduated fusing a must have?

[scottrod]

>> “ground” is a convenient fantasy

Until it rushes up to meet you, then it's an inconvenient reality!

Card was retired. The aircraft was in the experimental category and the owner had wired it in an unconventional manner, not in the manuals. Argh!

[Henrik_Volkers · Accepted solution]

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@scottrod wrote:

>> “ground” is a convenient fantasy

Until it rushes up to meet you, then it's an inconvenient reality!

Card was retired. The aircraft was in the experimental category and the owner had wired it in an unconventional manner, not in the manuals. Argh!

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In an aircraft ground rushes up to meet you? Isn't it the other way ?

A gallery of alternative current limiters:

Spoiler

I like the 350A fuse , a real circuit breaker  if blown 😄