Page:Popular Science Monthly Volume 92.djvu/164

 148 Popular Science Monthly

An Emergency Battery for Starting A Winding Machine with a

an Automobile Motor

��AT least 50 per cent of the modern . automobiles use battery ignition. As this system sometimes gives trouble, even in the most expensive cars, I de-

���6 DRY

-TO POSITIVE TERMINAL CELLS

-TO NEGATIVE TERMINAL

A set of dry batteries 'placed under the seat to aid in starting the automobile motor

vised a method for producing an emer- gency current as shown in the illustration. This consists of six dry cells securely tied together in a triangle shape and wired in series with a 4-ft. length of well insulated copper wire attached to each of the negative and positive terminals. These wires are used to make connections with the storage battery terminals for starting the motor; then they are disconnected.

The batteries will last a long time for this emergency work. If the storage battery gives too much trouble, remove the filUng caps and make sure that the liquid is y^ in. above the top of the lead plates. Should the level be below this point, add enough distilled water to make up the deficiency. Keep all the battery and wire terminals bright by scraping them with a sharp knife about once a month, and make sure that there is no short circuit in the dashboard switches and that no battery wire or other wire is chafing against any metal to produce a short circuit. In this way a battery may be kept at its highest efficiency. — P. P. AvERY.

��Revolution Counter

THE winding machine shown in the drawing is of service for winding various types of coils, transformer "pies," etc., in the amateur's shop, or wherever there is no small screw-cutting lathe. The novel feature of the machine is the simple method employed for determining the number of revolutions the spindle makes during the process of winding a coil.

A piece of round stock, C, Yi in. in diameter and 12 in. long, is threaded 3 in. of its length at one end, and has a 3/16-in. hole drilled in the opposite end to a depth of Yi in. A three- or four-step set of cone pulleys is made fast to the center of C by keying or with a forced fit. The spindle is mounted in bearings upon standards Z> as shown, and the spindle unit thus assembled is permanently fast- ened to a baseboard 2 in. by 6 in. by 5 ft. A piece of 3/16-in. round rod 3 ft. 4 in. long is then threaded with a die, cutting 32 threads per inch for its entire length with the exception of about 2 in. at one end. The stand E is made and fastened to the baseboard at the point shown, and acts as a bearing for one end of the threaded rod. The end of the rod left unthreaded is now inserted in its bearing in the standard E. The opposite end is inserted in the hole drilled in the end of

���A threaded rod on the lathe spindle registers the exact number of turns of wire on the coil

��C, to which it is soldered. A yard stick is mounted in line with the threaded rod and directly above it, and is held in place by two strap-iron standards S>. A loop of fine iron wire is passed around the threaded rod, the ends are twisted together and a small lead weight is fastened to the twisted ends as shown

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