Lightning protection apparatus, on EMC demonstration

A new EMC-demonstration has been built in the high voltage laboratory of the Eindhoven University of Technology. An ordinary portable cassette recorder and its loudspeaker are mounted at both ends of a copper tube coil. Through the coil flows the chopping current of a lightning surge generator. A 200 kV spark-gap is mounted over the coil; a breakdown occurs close to the sensitive microelectronics. The cassette recorder is effectively protected by small EMC-cabinets and by a proper lay-out for the wiring between recorder and its loudspeaker, i.e. inside the copper tub