The Birth of Presetting: 75 years since the Strand ‘Electronic’ Dimmer transformed British stage lighting

Abstract

Between the two world wars British theatre was very conservative, and despite technological lighting dimmer developments in Europe and the USA, continued to solely use large resistance dimmer switchboards. After the second world war, new American dimmers using thyratrons challenged this complacency in Strand Electric’s management. Strand then also applied this technology by introducing a novel three valve, DC, phase control dimmer in 1949 called the ‘Electronic’. The design offered two presets with dipless crossfading and obviated the need for an increased mains supply voltage to overcome valve loss. All other manufacturers used conventional two valve AC phase control arrangements, needing a boosted supply. Unfortunately the many drawbacks of Strand’s approach and poor reliability led to a short market life of just five years. Despite the difficulties, the Electronic provided accurate presetting of lighting levels to the British stage for the first time.

Keywords: Stage lightingdimmer, thyratron, strand electric, theatre, theater, presetting