Note: This is a sub-section of BTH
A brand of electric filament lamps for cars and other uses, and electronic valves, made by BTH Rugby.
1911 Electrical Exhibition. Mazda lamps from 6 to 600 watts and other equipment.
WWI Using its experience in making filament lamps, BTH became a manufacturer of radio valves.
1921 A factory for producing glass, drawing and blowing glass for lamps and valves was made at Chesterfield. Westlake bulb-blowing machines were installed.
1928 BTH became part of the new AEI which concentrated valve work at Cosmos Lamp Works. BTH ceased valve making except for special purpose valves that it required for its production of non-domestic electronic equipment
1937 British Industries Fair Advert for Lighting Products, including Mazda Mercra; Projector Lamps; Mazda Gas-filled and Mazda Vacuum Lamps; Light Tubes for Architectural Lighting; B. T. H. Lighting Equipment for Street, Industrial and Floodlighting; Maxdalux Floodlight Projectors; etc. (Stand No. Cb.607 and Cb.504)