Home » Recent acquisitions » Acorn ADFS disks » adfs_AcornUser_199508.adf » !Regulars » Regulars/StarInfo/Marshall/!Any/!Help
Regulars/StarInfo/Marshall/!Any/!Help
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » Recent acquisitions » Acorn ADFS disks » adfs_AcornUser_199508.adf » !Regulars |
| Filename: | Regulars/StarInfo/Marshall/!Any/!Help |
| Read OK: | ✔ |
| File size: | 085B bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
Any RC ~~~~~~~ by P.E.Marshall Only a finite number of different resistor values are manufactured. Low cost ranges in common use have only 12 'preferred' values per decade, thus there is a difference between adjacent values of 20%, although the resistors themselves may have a tolerance of 5% or even 2%. Virtually any intermediate value can be obtained by using two resistors in series or in parallel. A parallel pair is usually more convenient for a printed circuit board layout, while series is better for high voltage applications. The value of resistors in parallel is given by R = 1/(1/r1+1/r2) and in series simply by R = r1 + r2. This program calculates the two values required to obtain a given target resistance. It may be desirable to keep the two values as close to each other as possible to aid power sharing or voltage distribution, so the option is provided to acheive this, provided the tolerance of the target value can be relaxed. In 'Highest Accuracy' mode, the results are only displayed when closer than 20%, but usually the results are surprisingly accurate. Another mode allows one of the values to be chosen by the user. This can be faster if you know near enough what one value will be. The program also the user if a single value would be closer than a pair. Select the various options, then enter the target value in the 'required' box. Press return, or click on the 'Calculate' icon. The displayed results can also be altered to see the result of changing one or both values. The algorithm used is rather crude - the program simply tries every combination to see which is best and so is therefore rather slow. No doubt a proper mathematician could come up with something better! Capacitors can also be calculated, and 12 or 24 values per decade selected. When entering the value to be calculated the suffix K, M, n or u (for �) may be used. Ohms or pf are used by default. Notice I didn't use the omega symbol for ohms because there isn't one! The program redefines system font character 191 to omega (normally an upside-down question mark!) P.E.Marshall 21/11/94.
00000000 41 6e 79 20 52 43 0a 7e 7e 7e 7e 7e 7e 7e 0a 0a |Any RC.~~~~~~~..| 00000010 62 79 20 50 2e 45 2e 4d 61 72 73 68 61 6c 6c 0a |by P.E.Marshall.| 00000020 0a 0a 4f 6e 6c 79 20 61 20 66 69 6e 69 74 65 20 |..Only a finite | 00000030 6e 75 6d 62 65 72 20 6f 66 20 64 69 66 66 65 72 |number of differ| 00000040 65 6e 74 20 72 65 73 69 73 74 6f 72 20 76 61 6c |ent resistor val| 00000050 75 65 73 20 61 72 65 20 6d 61 6e 75 66 61 63 74 |ues are manufact| 00000060 75 72 65 64 2e 20 0a 4c 6f 77 20 63 6f 73 74 20 |ured. .Low cost | 00000070 72 61 6e 67 65 73 20 69 6e 20 63 6f 6d 6d 6f 6e |ranges in common| 00000080 20 75 73 65 20 68 61 76 65 20 6f 6e 6c 79 20 31 | use have only 1| 00000090 32 20 27 70 72 65 66 65 72 72 65 64 27 20 76 61 |2 'preferred' va| 000000a0 6c 75 65 73 20 70 65 72 20 0a 64 65 63 61 64 65 |lues per .decade| 000000b0 2c 20 74 68 75 73 20 74 68 65 72 65 20 69 73 20 |, thus there is | 000000c0 61 20 64 69 66 66 65 72 65 6e 63 65 20 62 65 74 |a difference bet| 000000d0 77 65 65 6e 20 61 64 6a 61 63 65 6e 74 20 76 61 |ween adjacent va| 000000e0 6c 75 65 73 20 6f 66 20 32 30 25 2c 0a 61 6c 74 |lues of 20%,.alt| 000000f0 68 6f 75 67 68 20 74 68 65 20 72 65 73 69 73 74 |hough the resist| 00000100 6f 72 73 20 74 68 65 6d 73 65 6c 76 65 73 20 6d |ors themselves m| 00000110 61 79 20 68 61 76 65 20 61 20 74 6f 6c 65 72 61 |ay have a tolera| 00000120 6e 63 65 20 6f 66 20 35 25 20 6f 72 20 0a 65 76 |nce of 5% or .ev| 00000130 65 6e 20 32 25 2e 0a 0a 56 69 72 74 75 61 6c 6c |en 2%...Virtuall| 00000140 79 20 61 6e 79 20 69 6e 74 65 72 6d 65 64 69 61 |y any intermedia| 00000150 74 65 20 76 61 6c 75 65 20 63 61 6e 20 62 65 20 |te value can be | 00000160 6f 62 74 61 69 6e 65 64 20 62 79 20 75 73 69 6e |obtained by usin| 00000170 67 20 74 77 6f 20 0a 72 65 73 69 73 74 6f 72 73 |g two .resistors| 00000180 20 69 6e 20 73 65 72 69 65 73 20 6f 72 20 69 6e | in series or in| 00000190 20 70 61 72 61 6c 6c 65 6c 2e 20 41 20 70 61 72 | parallel. A par| 000001a0 61 6c 6c 65 6c 20 70 61 69 72 20 69 73 20 75 73 |allel pair is us| 000001b0 75 61 6c 6c 79 20 6d 6f 72 65 0a 63 6f 6e 76 65 |ually more.conve| 000001c0 6e 69 65 6e 74 20 66 6f 72 20 61 20 70 72 69 6e |nient for a prin| 000001d0 74 65 64 20 63 69 72 63 75 69 74 20 62 6f 61 72 |ted circuit boar| 000001e0 64 20 6c 61 79 6f 75 74 2c 20 77 68 69 6c 65 20 |d layout, while | 000001f0 73 65 72 69 65 73 20 69 73 20 62 65 74 74 65 72 |series is better| 00000200 0a 66 6f 72 20 68 69 67 68 20 76 6f 6c 74 61 67 |.for high voltag| 00000210 65 20 61 70 70 6c 69 63 61 74 69 6f 6e 73 2e 0a |e applications..| 00000220 0a 54 68 65 20 76 61 6c 75 65 20 6f 66 20 72 65 |.The value of re| 00000230 73 69 73 74 6f 72 73 20 69 6e 20 70 61 72 61 6c |sistors in paral| 00000240 6c 65 6c 20 69 73 20 67 69 76 65 6e 20 62 79 20 |lel is given by | 00000250 52 20 3d 20 31 2f 28 31 2f 72 31 2b 31 2f 72 32 |R = 1/(1/r1+1/r2| 00000260 29 20 61 6e 64 0a 69 6e 20 73 65 72 69 65 73 20 |) and.in series | 00000270 73 69 6d 70 6c 79 20 62 79 20 20 20 52 20 3d 20 |simply by R = | 00000280 72 31 20 2b 20 72 32 2e 20 20 20 20 20 20 20 20 |r1 + r2. | 00000290 20 20 20 20 20 20 20 20 20 20 0a 0a 54 68 69 73 | ..This| 000002a0 20 70 72 6f 67 72 61 6d 20 63 61 6c 63 75 6c 61 | program calcula| 000002b0 74 65 73 20 74 68 65 20 74 77 6f 20 76 61 6c 75 |tes the two valu| 000002c0 65 73 20 72 65 71 75 69 72 65 64 20 74 6f 20 6f |es required to o| 000002d0 62 74 61 69 6e 20 61 20 67 69 76 65 6e 20 0a 74 |btain a given .t| 000002e0 61 72 67 65 74 20 72 65 73 69 73 74 61 6e 63 65 |arget resistance| 000002f0 2e 20 49 74 20 6d 61 79 20 62 65 20 64 65 73 69 |. It may be desi| 00000300 72 61 62 6c 65 20 74 6f 20 6b 65 65 70 20 74 68 |rable to keep th| 00000310 65 20 74 77 6f 20 76 61 6c 75 65 73 20 61 73 20 |e two values as | 00000320 0a 63 6c 6f 73 65 20 74 6f 20 65 61 63 68 20 6f |.close to each o| 00000330 74 68 65 72 20 61 73 20 70 6f 73 73 69 62 6c 65 |ther as possible| 00000340 20 74 6f 20 61 69 64 20 70 6f 77 65 72 20 73 68 | to aid power sh| 00000350 61 72 69 6e 67 20 6f 72 20 76 6f 6c 74 61 67 65 |aring or voltage| 00000360 20 0a 64 69 73 74 72 69 62 75 74 69 6f 6e 2c 20 | .distribution, | 00000370 73 6f 20 74 68 65 20 6f 70 74 69 6f 6e 20 69 73 |so the option is| 00000380 20 70 72 6f 76 69 64 65 64 20 74 6f 20 61 63 68 | provided to ach| 00000390 65 69 76 65 20 74 68 69 73 2c 20 70 72 6f 76 69 |eive this, provi| 000003a0 64 65 64 0a 74 68 65 20 74 6f 6c 65 72 61 6e 63 |ded.the toleranc| 000003b0 65 20 6f 66 20 74 68 65 20 74 61 72 67 65 74 20 |e of the target | 000003c0 76 61 6c 75 65 20 63 61 6e 20 62 65 20 72 65 6c |value can be rel| 000003d0 61 78 65 64 2e 20 0a 0a 49 6e 20 27 48 69 67 68 |axed. ..In 'High| 000003e0 65 73 74 20 41 63 63 75 72 61 63 79 27 20 6d 6f |est Accuracy' mo| 000003f0 64 65 2c 20 74 68 65 20 72 65 73 75 6c 74 73 20 |de, the results | 00000400 61 72 65 20 6f 6e 6c 79 20 64 69 73 70 6c 61 79 |are only display| 00000410 65 64 20 77 68 65 6e 20 63 6c 6f 73 65 72 0a 74 |ed when closer.t| 00000420 68 61 6e 20 32 30 25 2c 20 62 75 74 20 75 73 75 |han 20%, but usu| 00000430 61 6c 6c 79 20 74 68 65 20 72 65 73 75 6c 74 73 |ally the results| 00000440 20 61 72 65 20 73 75 72 70 72 69 73 69 6e 67 6c | are surprisingl| 00000450 79 20 61 63 63 75 72 61 74 65 2e 0a 41 6e 6f 74 |y accurate..Anot| 00000460 68 65 72 20 6d 6f 64 65 20 61 6c 6c 6f 77 73 20 |her mode allows | 00000470 6f 6e 65 20 6f 66 20 74 68 65 20 76 61 6c 75 65 |one of the value| 00000480 73 20 74 6f 20 62 65 20 63 68 6f 73 65 6e 20 62 |s to be chosen b| 00000490 79 20 74 68 65 20 75 73 65 72 2e 20 54 68 69 73 |y the user. This| 000004a0 0a 63 61 6e 20 62 65 20 66 61 73 74 65 72 20 69 |.can be faster i| 000004b0 66 20 79 6f 75 20 6b 6e 6f 77 20 6e 65 61 72 20 |f you know near | 000004c0 65 6e 6f 75 67 68 20 77 68 61 74 20 6f 6e 65 20 |enough what one | 000004d0 76 61 6c 75 65 20 77 69 6c 6c 20 62 65 2e 0a 0a |value will be...| 000004e0 54 68 65 20 70 72 6f 67 72 61 6d 20 61 6c 73 6f |The program also| 000004f0 20 74 68 65 20 75 73 65 72 20 69 66 20 61 20 73 | the user if a s| 00000500 69 6e 67 6c 65 20 76 61 6c 75 65 20 77 6f 75 6c |ingle value woul| 00000510 64 20 62 65 20 63 6c 6f 73 65 72 20 74 68 61 6e |d be closer than| 00000520 20 61 20 70 61 69 72 2e 0a 0a 53 65 6c 65 63 74 | a pair...Select| 00000530 20 74 68 65 20 76 61 72 69 6f 75 73 20 6f 70 74 | the various opt| 00000540 69 6f 6e 73 2c 20 74 68 65 6e 20 65 6e 74 65 72 |ions, then enter| 00000550 20 74 68 65 20 74 61 72 67 65 74 20 76 61 6c 75 | the target valu| 00000560 65 20 69 6e 20 74 68 65 20 27 72 65 71 75 69 72 |e in the 'requir| 00000570 65 64 27 0a 62 6f 78 2e 20 50 72 65 73 73 20 72 |ed'.box. Press r| 00000580 65 74 75 72 6e 2c 20 6f 72 20 63 6c 69 63 6b 20 |eturn, or click | 00000590 6f 6e 20 74 68 65 20 27 43 61 6c 63 75 6c 61 74 |on the 'Calculat| 000005a0 65 27 20 69 63 6f 6e 2e 20 54 68 65 20 64 69 73 |e' icon. The dis| 000005b0 70 6c 61 79 65 64 20 0a 72 65 73 75 6c 74 73 20 |played .results | 000005c0 63 61 6e 20 61 6c 73 6f 20 62 65 20 61 6c 74 65 |can also be alte| 000005d0 72 65 64 20 74 6f 20 73 65 65 20 74 68 65 20 72 |red to see the r| 000005e0 65 73 75 6c 74 20 6f 66 20 63 68 61 6e 67 69 6e |esult of changin| 000005f0 67 20 6f 6e 65 20 6f 72 20 62 6f 74 68 0a 76 61 |g one or both.va| 00000600 6c 75 65 73 2e 0a 0a 54 68 65 20 61 6c 67 6f 72 |lues...The algor| 00000610 69 74 68 6d 20 75 73 65 64 20 69 73 20 72 61 74 |ithm used is rat| 00000620 68 65 72 20 63 72 75 64 65 20 2d 20 74 68 65 20 |her crude - the | 00000630 70 72 6f 67 72 61 6d 20 73 69 6d 70 6c 79 20 74 |program simply t| 00000640 72 69 65 73 20 65 76 65 72 79 0a 63 6f 6d 62 69 |ries every.combi| 00000650 6e 61 74 69 6f 6e 20 74 6f 20 73 65 65 20 77 68 |nation to see wh| 00000660 69 63 68 20 69 73 20 62 65 73 74 20 61 6e 64 20 |ich is best and | 00000670 73 6f 20 69 73 20 74 68 65 72 65 66 6f 72 65 20 |so is therefore | 00000680 72 61 74 68 65 72 20 73 6c 6f 77 2e 20 4e 6f 0a |rather slow. No.| 00000690 64 6f 75 62 74 20 61 20 70 72 6f 70 65 72 20 6d |doubt a proper m| 000006a0 61 74 68 65 6d 61 74 69 63 69 61 6e 20 63 6f 75 |athematician cou| 000006b0 6c 64 20 63 6f 6d 65 20 75 70 20 77 69 74 68 20 |ld come up with | 000006c0 73 6f 6d 65 74 68 69 6e 67 20 62 65 74 74 65 72 |something better| 000006d0 21 0a 0a 43 61 70 61 63 69 74 6f 72 73 20 63 61 |!..Capacitors ca| 000006e0 6e 20 61 6c 73 6f 20 62 65 20 63 61 6c 63 75 6c |n also be calcul| 000006f0 61 74 65 64 2c 20 61 6e 64 20 31 32 20 6f 72 20 |ated, and 12 or | 00000700 32 34 20 76 61 6c 75 65 73 20 70 65 72 20 64 65 |24 values per de| 00000710 63 61 64 65 0a 73 65 6c 65 63 74 65 64 2e 20 20 |cade.selected. | 00000720 57 68 65 6e 20 65 6e 74 65 72 69 6e 67 20 74 68 |When entering th| 00000730 65 20 76 61 6c 75 65 20 74 6f 20 62 65 20 63 61 |e value to be ca| 00000740 6c 63 75 6c 61 74 65 64 20 74 68 65 20 73 75 66 |lculated the suf| 00000750 66 69 78 20 4b 2c 20 4d 2c 20 0a 6e 20 6f 72 20 |fix K, M, .n or | 00000760 75 20 28 66 6f 72 20 b5 29 20 6d 61 79 20 62 65 |u (for .) may be| 00000770 20 75 73 65 64 2e 20 4f 68 6d 73 20 6f 72 20 70 | used. Ohms or p| 00000780 66 20 61 72 65 20 75 73 65 64 20 62 79 20 64 65 |f are used by de| 00000790 66 61 75 6c 74 2e 20 4e 6f 74 69 63 65 20 0a 49 |fault. Notice .I| 000007a0 20 64 69 64 6e 27 74 20 75 73 65 20 74 68 65 20 | didn't use the | 000007b0 6f 6d 65 67 61 20 73 79 6d 62 6f 6c 20 66 6f 72 |omega symbol for| 000007c0 20 6f 68 6d 73 20 62 65 63 61 75 73 65 20 74 68 | ohms because th| 000007d0 65 72 65 20 69 73 6e 27 74 20 6f 6e 65 21 20 54 |ere isn't one! T| 000007e0 68 65 0a 70 72 6f 67 72 61 6d 20 72 65 64 65 66 |he.program redef| 000007f0 69 6e 65 73 20 73 79 73 74 65 6d 20 66 6f 6e 74 |ines system font| 00000800 20 63 68 61 72 61 63 74 65 72 20 31 39 31 20 74 | character 191 t| 00000810 6f 20 6f 6d 65 67 61 20 28 6e 6f 72 6d 61 6c 6c |o omega (normall| 00000820 79 20 61 6e 0a 75 70 73 69 64 65 2d 64 6f 77 6e |y an.upside-down| 00000830 20 71 75 65 73 74 69 6f 6e 20 6d 61 72 6b 21 29 | question mark!)| 00000840 0a 0a 0a 50 2e 45 2e 4d 61 72 73 68 61 6c 6c 20 |...P.E.Marshall | 00000850 20 20 32 31 2f 31 31 2f 39 34 2e | 21/11/94.| 0000085b
.