Page:Popular Science Monthly Volume 88.djvu/305

 Popular Science Alonthly

��277

��An Electric Toy Semaphore

AN electric semaphore, if used in connection with a toy electric rail- way, will be interesting as well as in- structive.

Its construction requires an electro- magnet, (F) Fig. 1, pulling down an arm (A) when the magnet is energized. The arm is provided with a small ex- tension, so that it automatically shows the regulation colored lights at either po- sition of the arm. When at right an- gles to the standard it is supposed to signify "Stop" or "Danger,'' and a tiny red light shows. When hanging down at 45° from the standard it signifies "Clear Track" and only a small white light is seen.

���Fig. 1. The semaphore, if properly painted, has a very realistic appearance

Fig. 2 is the detail of the semaphore arm, which is made of light sheet brass or aluminum. The dimensions explain it thoroughly. The small lip which is to be bent outwards at right angles is the part to which the string (K) is at- tached.

Dimensions for a magnet cover (B) that will fit over a magnet taken from a medium sized bell or buzzer are shown in Fig. 3. This should be made of light sheet brass or aluminum. Small lips are provided which are bent in and sol-

��dered or riveted to an adjoining side. The dotted lines indicate where the metal should be bent. No dimensions are giv- en for the small holes, their size de- pending on the size screw used to fasten the cover to the base.

���Fig. 2. Detail of the semaphore arm, showing dimensions

The lamp (C), Fig. 4, is made of hard wood, IVs'' square, into which holes are bored as shown in the figure. Small 31/2 volt flashlight lamps fitted into min- iature sockets are put into the I/2'' hole as far as they will go. The end is then filled with putty so that it is lightproof. The %" holes are covered with tissue paper, the top with white and the bot- tom with red. The lights may be con- nected in multiple or series, depending on the voltage of the current. If small telephone switchboard lights and the opals which fit into the switchboard sockets can be procured the holes may be bored smaller and a much neater ef- fect secured.

The base (D) and the standard (E) are made of hard wood. The base should be about I/2'' thick. In Fig. 5, the plan of the arrangement of the parts is shown. The four small holes shown

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� ��Fig. 3. Dimensions for cover to fit magnet taken from bell or buzzer

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