http://home.graffiti.net/diverse:graffiti.net/sf2.jpg
No markings, a black potted box 7x7x 15mm external dimensions.
If a stepup transformer , why so small?

0.3 ohms between blue and red lead and 144 ohms between blue and brown lead
which goes directly to the trigger filament around the flash tube.
Red goes to ground and blue wire goes via 0.2uF, 250V capacitor to the SCR
cathode. 22mH and 20uH inductance

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Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/