Hawkins electrical guide ... : questions, answers & illustrations : a progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications ; a practical treatise (1914)
Hawkins, N. (Nehemiah), 1833-1928 · New York : T. Audel & Co. · leaf 314
rglar alarm circuits.A floor tread such as is shown in fig. 3,310 will complete an electriccircuit and ring a bell as long as one stands on the tread. A mattingmade of several switch contacts connected in parallel will act likeseveral floor treads all connected in parallel. This is one way of… … Fig. 3,310.—Floor tread and floor connector for office or dining room floor or any placewhere it is desirable to operate a signal on the floor. A slight pressure of the foot willclose the contact. Its construction is simple; its action perfect. When placed underrug or carpet it will not become…
Electrical engineering
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