Page:Popular Science Monthly Volume 90.djvu/330

 314

��Popular Science Monthly

��An Electric Gas. Lighter for the Kitchen Range

THE illustration shows the necessary parts and a wiring diagram for making an electric lighter for the gas range. A >^-in. spark coil A is con-

���Spark coil and its connection for lighting the gas by electricity

nected in line with the battery B and to an old telephone hook C, for the primary coil; the secondary is connected to a piece of fiber tube D, which is 3^-in. gap is made at F on the coil. When the fiber tube is taken from the hook it will close the primary circuit and a spark will jump the gap F, but when the end of the rod is placed near the burner on the stove a spark will issue therefrom and the gas will be lighted. The whole outfit can be inclosed in a neat box with the telephone hook extending, the box being placed on the wall near the stove.

��A Reliable Radiation and Tuning Indicator

THIS arrangement acts as a radiation indicator and serves the same pur- pose as the hot wire meter, except that it is less delicate. It does not interfere with the oscillations, and can be left in circuit continuously. The connections are shown in the drawing. The coil is constructed like a helix, and contains about a dozen turns of No. 8 wire wound on a form 3 in. in diameter and spaced 3^ in. apart. A movable contact is pro- vided as shown. The lamp used is a

��small four or six-volt carbon filament bulb, which may be obtained from any supply house. When the transmitter is in operation the lamp lights up. The coil is connected in shunt around six or more feet of the ground wire from the trans- mitter. The proper length must be de- termined by experiment. Only a small part of the high frequency current is passed through the coil by this arrange- ment.

To find the adjustment for maximum radiation at a desired wavelength, place the slides of the in- dicator coil so that all the turns are in circuit and adjust the antenna circuit inductance until the lamp lights up the highest. Now de- crease the number of turns on the indi- cator coil, thus de- creasing the bril- liancy of the lamp, and re-adjust the

transmitter circuits for the brightest light. Continue this process until the lamp lights up brilliantly with the least possible number of turns on the indi- cator coil. The transmitting station will then have a maximum radiation for the given wavelength.

This will be welcomed by those wire- less amateurs who could not make, or who had not the means to purchase a hot-wire meter.

���Substitute for a hot wire meter

��An Electric Gas Lighter Operated with a Push-Button

HAVING one of the single pull chain electric gas lighters I decided to change it into one that would work with

^j^^CONTACTS ~"^-" ELECTRO MAGNET

���An electro-magnet to operate the con- tact points for making spark on gas tip

a push-button, and I accomplish my pur- pose by making the simple arrangement illustrated. The single chain type, as is

�� �