. The principles underlying radio communication . enser only one-fourthas large could be used for the same power. As an illustration, if it isdesired to use \ kw. at 12,000 volts, with 1,000 sparks per second, 2X106X500 ;= microfarad. 1000X144X10« Knowing the total capacity required, the number of shoots of dielec-tric required to make up the condenser is obtained from the formula, ^O-OSSSXj^X^ (88) DESIGN FORMULAS. 385 ■where K is the dielectric constant of the insulating material, n is thenumber of sheets of dielectric, 8 is the area of each sheet in squarecentimeters, t is the thicknes
. The principles underlying radio communication . enser only one-fourthas large could be used for the same power. As an illustration, if it isdesired to use \ kw. at 12,000 volts, with 1,000 sparks per second, 2X106X500 ;= microfarad. 1000X144X10« Knowing the total capacity required, the number of shoots of dielec-tric required to make up the condenser is obtained from the formula, ^O-OSSSXj^X^ (88) DESIGN FORMULAS. 385 ■where K is the dielectric constant of the insulating material, n is thenumber of sheets of dielectric, 8 is the area of each sheet in squarecentimeters, t is the thickness in centimeters, and C is the capacityin microfarads. Supposing that mica is not available, it may be re-quired to find the number of sheets of glass required to make up thecondenser of microfarad required above. Suppose the sheets are15 by 20 cm., cm. thick, and the dielectric constant is 7. Substi-tuting in the formula just given, Thus nine sheets of this dielectric are needed. Fig. 207 y Fig. W. *5«ir*l It should be noted that the higher the spark frequency N the smallermay be the condenser used to give the same power. For this reason,as well as the others previously given, it is a distinct advantage tcuse a high spark frequency. When the voltage at which it is desired to operate the spark gap isso high that it will break down the particular insulation used in thecondensers or cause brush discharge, the connection of four con-densers, each of capacity O, as shown in Fig. 206, p. 380, will give aresultant capacity C, while subjecting each condenser to only half thfrfull voltage. TKANSM 1TTI NO APPARATUS. Inductance Coils.—The principal inductance coils in a radio set arethe primary and secondary of the oscillation transformer and the an-tenna loading coil, and the three corresponding coils of the receivingset. The three coils, oscillation primary and secondary and loadingcoil, are very similar. In actual
Size: 1572px × 1590px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookpublisherwashi, bookyear1922
