From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Table showing the effect of variation of make ratio (γ) for a standard battery ignition system.
| Identifier | ExFiles\Box 69\1\ scan0010 | |
| Date | 16th May 1924 | |
| R.R. STANDARD BATTERY IGNITION. TABLE SHOWING THE EFFECT OF VARIATION OF MAKE RATIO (γ) S = 2653 L = .0096 HENRY C_o = 3.16 AMPERE T' = .0143 SEC E = 8 VOLTS γ | .4343γ/S + | .4343γ/S - | r/S | e^(-r/S) | e^(-2r/S) | 1-e^(-r/S) (x) | 1-e^(-2r/S) (y) | S(1-e^(-r/S))^2 | S(e^(-r/S)-e^(-2r/S)) | AVERAGE D.C. FRACTION | R.M.S A.C. FRACTION SQ^2 | R.M.S A.C. FRACTION ROOT | FORM FACTOR | C' CURRENT AT BREAK (AMPERES) | C AVERAGE D.C. CURRENT (AMPERES) | I R.M.S A.C. CURRENT (AMPERES) | ECT ENERGY SUPPLIED (JOULES) | 1/2 LC'^2 ENERGY OF MAGNETIC FIELD (JOULES) | η EFFICIENCY I/2 LC'^2 / EY 0 | 0 | 0 | 1.000 | 1.000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | - | 0 | 0 | 0 | 0 | 0 | 1.00 .1 | .164 | T.836 | .6855 | .4699 | .315 | .530 | .084 | .070 | .016 | .002 | .040 | 2.5 | .996 | .051 | .126 | .0057 | .0047 | .825 .2 | .328 | T.672 | .4699 | .2208 | .530 | .779 | .141 | .103 | .059 | .021 | .145 | 2.46 | 1.675 | .186 | .458 | .0213 | .0135 | .634 .3 | .492 | T.508 | .3221 | .1038 | .678 | .896 | .180 | .119 | .120 | .059 | .243 | 2.02 | 2.14 | .379 | .768 | .0434 | .0220 | .507 .4 | .656 | T.344 | .2208 | .049 | .779 | .951 | .207 | .126 | .193 | .112 | .336 | 1.74 | 2.46 | .610 | 1.06 | .0698 | .0290 | .415 .5 | .818 | T.182 | .152 | .023 | .848 | .977 | .225 | .1295 | .275 | .1795 | .424 | 1.54 | 2.68 | .870 | 1.34 | .0995 | .0345 | .347 .55 | .901 | T.099 | .1256 | .0158 | .874 | .984 | .232 | .1305 | .318 | .2165 | .465 | 1.46 | 2.76 | 1.00 | 1.47 | .1144 | .0366 | .320 .6 | .984 | T.016 | .1038 | .0108 | .896 | .989 | .237 | .131 | .363 | .257 | .507 | 1.395 | 2.83 | 1.15 | 1.60 | .1318 | .0386 | .293 .7 | 1.145 | T.854 | .0715 | .0051 | .928 | .995 | .246 | .132 | .454 | .340 | .583 | 1.28 | 2.93 | 1.43 | 1.84 | .1638 | .0415 | .253 .8 | 1.311 | T.689 | .049 | .0024 | .951 | .998 | .252 | .1324 | .548 | .428 | .654 | 1.19 | 3.01 | 1.73 | 2.06 | .1980 | .0435 | .220 .9 | 1.521 | T.479 | .0301 | .0009 | .970 | .999 | .257 | .1325 | .643 | .5185 | .720 | 1.12 | 3.07 | 2.03 | 2.27 | .2320 | .0453 | .195 1.0 | 1.640 | T.360 | .0227 | .0006 | .977 | .999 | .259 | .1325 | .741 | .6145 | .784 | 1.06 | 3.09 | 2.34 | 2.48 | .268 | .0458 | .171 H.E.W. 16-5-24 | ||