Neon sign transformer vs DMM

[@TheElectronicDilettante]

Excellent video, as always. Thanks!

[@pa4tim]

BM869S, over 40kV from a failing high energy devise. At the output of the devise was an open 75k resistor that exploded. The Brymen was at a point that should be 400Vand exploded. Measuring with a 40kV probe at that point the an other meter gave overload (max voltage it could display was 50kV ) The Brymen had an exploded PTC, 3 dead MOVs, a burned trace. After replacing the parts and repairing the tracxe, the Brymen is still working fine and within cal.

[@s_s-g4d]

I'd imagine it should have evaporated at that voltage and if the source was low enough impedance (high energy). It's interesting that it didn't, even despite there's no HRC fuse (or any fuse for that matter) in the voltage input path.

[@poormanselectronicsbench2021]

Pretty amazing, because at 40+KV, you would figure that any arc that started would continue to just burn and irrepairably damage the meter's innards. That kind of voltage would most likely easily jump and sustain a 2 inch gap once an arc is started.

[@pa4tim]

@@poormanselectronicsbench2021 I work behind an adjustable over current protection circuit and a big red kill switch just in case. So it can not continue otherwise the meter maybe would have been in worse shape. ( trace between input and MOVs burned away)

[@joesmith-je3tq]

@@pa4tim The only time I work with voltages that high are involving automotive ignition systems. There isn't enough energy to make a DMM explode. It could certainly damage one.

[@SeanBZA]

Standard test for wire is to have a bath of slightly saline water, and the wire in the water, so as to find the weak spots in the insulation. For the better manufacturers they use a salt water section in the cooling path for the extruder, and a paint marker to dab a blob of paint on the wire, so that that roll of wire can be pulled out, and then recycled, or cut into 2 smaller reels for sale as short rolls.

[@joesmith-je3tq]

I was referring to the leads, not the wire. Their is a separate standard for them, just like the safety standards for the meters.

[@joef108]

Interesting- thanks Joe!

[@JenkinsUSA]

I’m pretty sure if that was my leads I would be eol. Great video! 😊