of wire to each coil. Fix these by
soldering or bending over the ends of the tacks. Then nail two
strips of copper (G) in such position that the side brush will
remain on the one as long as the end brush remains on the tacks on
that side.
Put sides about 1-1/2 in. high around this apparatus, raising the
board a little from the bottom to allow room for the coil. A lid
may be added if desired. Connect up as shown.
--Contributed by Chas. H. Boyd, Philadelphia.
** How to Make a Simple Water Rheostat [43]
[Illustration: Wiring Plan for Water Rheostat]
The materials necessary are: One 5-point wood-base switch, 4 jars,
some sheet copper or brass for plates, about 5 ft. of
rubber-covered wire, and some No. 18 gauge wire for the wiring.
The size of the jars depends on the voltage. If you are going to
use a current of low tension, as from batteries, the jars need not
be very large, but if you intend to use the electric light current
of 110 voltage it will be necessary to use large jars or wooden
boxes made watertight, which will hold about 6 or 7 gal. Each jar
to be filled with 20 parts water to 1 part sulphuric acid.
Pages:
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113