A Set of Electric Chimes
A set of electric dinner chimes is a welcome and useful addition to many households, and may be made at a trifling cost by the average person handy with tools. The completed article is shown in Fig. 1, the details in Fig. 2, and the wiring diagram in Fig. 3. The woodwork is of ¹⁄₂-in. stock. The back A, Fig. 2, is 1¹⁄₂ in., by 9³⁄₄ in. long. The ends may be shaped to suit the builder’s fancy. The shelf B is 4 in. square, and is fastened to the back piece 2¹⁄₄ in. from the upper end. It supports the magnets C, which are made on cores, ³⁄₈ in. in diameter and ³⁄₄ in. long, with ends ¹⁄₁₆ in. by 1 in. in diameter. The spools are wound full of No. 28 silk-covered copper magnet wire. These coils mounted on the shelf by means brass straps D. Four magnets are used, the forward one being omitted in Fig. 2.
Fig. 1
Fig. 2
Fig. 3
When the Buttons are Pressed, Tones are Given Forth by the Electrically Operated Gongs
The supports E, for the tubes, consist of ¹⁄₂-in. lengths of ¹⁄₄-in. square brass rod. One end of the rod is drilled and tapped for an 8-32 screw which holds the support in place. Drill a small hole, ¹⁄₄ in. from the end, for the pin G, made of steel wire. The tapper H is made from a 4¹⁄₂-in. length of stiff iron wire; 1¹⁄₄ in. from one end a ³⁄₈-in. cube of iron, J, is soldered, the wire passing through it. The ends of the wire are fitted with balls as shown. A nickeled gong, K, covers the four magnets. The end of the tapper is passed through the hole in the gong and the ball riveted into place.
Four ³⁄₄-in. diameter tubes are used, respectively 3, 4, 5, and 6 in. long. When the apparatus is assembled as shown, and one of the magnets is energized, the latter will draw the iron cube J toward it, and the tapper will strike one of the tubes.
To control the current supplying the magnets, four small push buttons mounted on a wooden base are used. They are wired up with the battery and coils, as shown in Fig. 3. A wire from each of the coils runs directly to one terminal of the battery, the other wire from each coil being connected to a separate push button. The other sides of the push buttons are connected to the battery. By this means any of the magnets may be energized at will, the coils and corresponding push buttons being marked L and M, etc., alphabetically.