Surface mount spark gap?

[N_Cook]

1206 footprint inside a Chinese in-line smps. Amber colour showing an
underlying zigzag track like pcb trace inductor and a tiny fuzzy bit. In
series with 15K , only, and going between the coldside pre-rectifier hf ac
and the 48V dc output . Does not measure 0 ohm, not a fuse in that
situation. Overlay marked ED201 , ED = electrostatic discharge? Note, its on
the cold side. "surface mount" "spark gap" in goomages threw up nothing
Bad solder joint on the v reg should be the problem but just wanted to check
what this new-to-me device might be. Case cracked open painlessly

[N_Cook]

N_Cook <div...@tcp.co.uk> wrote in message
news:i3ej86$er3$1...@news.eternal-september.org...

looking under x30 it has a gold coloured if not gold plated surface with a
bit of ptrofiling, perhaps hiding another surface under as seems continuous
metalling from land to land, with a tiny brown dot in the middle and clear
plastic cover over

[N_Cook]

What a plonker. Now it is knocking out 48V DC, its function is obvious. It
would have been much more obvious if it was not at the edge of the board
with the L missing off the overlay designation ED201, and a more obvious
window in the casing.

[Adrian C]

A photon gap then?

:-)

--
Adrian C

[N_Cook]

Adrian C <em...@here.invalid> wrote in message
news:8c2vjr...@mid.individual.net...

I did discover that there are such things as SM gas discharge
tubes/arresters

[Robert Macy]

One time we used a series of gas tube spark gaps for protecting the
circuitry, but could not figure out why they weren't meeting spec and
firing closer to 400 V than over 600, until...some enlightened person
suggested that maybe it was because we stuck them inside a dark oil
tank and there was no light! yes, that was it. Later we noticed the
problem went away when the gas was somehow 'pretriggered'. and didn't
matter whether in light or dark. Radioactive isotope doping?