Automatic Electric Company Limited Victor Works Broadgreen Liverpool England

They exhibited their well known Strowger System (named after the firm's Liverpool works) of Centralised Street Lighting Control. Working over the existing mains, the standard switching provides "all on," "half off," and "off" conditions of lighting. High frequency current is superimposed on the neutral and phase wires, the signal used to switch relays in the receiving equipment. - Public Lighting #3, 1936

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