The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 189
b keeps the armature in position. When attracted, the latterrocks on the knife edge, and insulated studs on the upperend raise the long centre springs at d from the lower springsinto contact with the upper short springs shown. In Fig. 187 the instrument is shown furnished with a tripleset of three… … CUT-OFF RELAY Side Elevation Front Elevation Fig. 188 break relay. It can, of course, be arranged in a simplerform according to the number of sets of springs employed,These relays are generally wound to a resistance of 250 ohms. RELAY AND LAMP SIGNALLING 165 and the triple form operates with a…
Telephone
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