Publication: Electrical Review
New York, NY, United States
Series Incandescent Lighting
We recently published a description of the combination socket and series incandescent lamp which the Bernstein Electric Company make a specialty of. The socket-shell or cap is made of insulating material, and affords absolute protection against shocks; the socket combines the automatic cut-out and the "off and on" key.
The introduction of series incandescent lamps has developed a necessity for special devices for particular cases, and some of these are shown by the annexed cuts. As a loop of incandescent lamps in series presents a high resistance, an arc must form between the terminals of the switch controlling the loop whenever the switch is opened, and to prevent the maintenance of this arc the Bernstein Company have made a special switch, of which two types are shown in the cuts. An electro-magnet is combined with the switch in such a manner that the space between the switch terminals lies in the magnetic field, the coil of the magnet being in direct circuit. The arc formed between the terminals when the switch is opened is destroyed by the lines of force, and the action is said to be instantaneous. Of the two types shown, one is a simple "shunt" switch for controlling a few lamps, and the other is a "cut-off " switch for entirely disconnecting the loop from the main circuit, and is especially for use on outside of buildings.
The street fixtures represented by the cuts were designed by the company in consequence of calls from many of its customers who use its lamps for street lighting. The cuts show the fixture with the lamp in position, as in use, and also with the lamp removed and the socket exposed, as when the cut-out is to be renewed.
The company has now got its new factory into good running order, and is prepared to produce its lamps and fittings in large quantities; it reports steadily increasing demand, with indications that even its increased manufacturing facilities will soon be taxed to their utmost capacity.