The Automotive Ignition Coil
A 1932 technical report from the National Advisory Committee for Aeronautics, catalogued through NASA's Technical Reports Server, presenting oscillograph traces of automotive ignition coil behaviour. The pictures are plates of twelve-frame grids, each frame showing a bright white waveform plotted over a dark ground with a fine tick-mark time scale and small handwritten or typeset labels. A designer might take the rhythmic graph-paper grids and crisp white curves as a source for scientific chart or instrument-panel motifs.
