SERIES INCANDESCENT LAMPS ON CONSTANT CURRENT TRANSFORMERS
Series incandescent lamps were made for use on constant current transformers superseding the “Municipal” and “Shunt Box” systems. The large Edison, now called the Mogul Screw base, was adopted and the short circuiting film cut-out was removed from the base and placed between prongs attached to the socket.
Holder.
Socket.
Holder and socket.
Series Incandescent Lamp Socket with Film Cutout, 1900.
The “Large Edison,” now called Mogul Screw, base was standardized and the short circuiting device put on the socket terminals.