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Commit | Line | Data |
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a24f7a5c P |
1 | IDENTIFICATION DIVISION |
2 | PROGRAM-ID Comet | |
3 | VERSION 20240205 | |
4 | COMMENT A comet moves on a parabolic orbit in the gravitational field of the stationary sun. | |
5 | COMMENT Its orbital plane coincides with the plane of the Earth's orbit, which is assumed to be circular. | |
6 | COMMENT The perihelion distance is one third of the Earth's orbital radius R.E. | |
7 | COMMENT How long does the comet move within the Earth's orbit? | |
8 | COMMENT t(r)=root(2/(gamma*m(sun))*integral from 1/3RE to RE (r/root(r-1/3 RE)) dr | |
9 | ||
10 | ENVIRONMENT DIVISION | |
11 | ENGINE Anabrid-THAT | |
12 | TIMEBASE 100ms # use SLOW on both integrators | |
13 | REQUIRES COEFFICIENT 3, INTEGRATOR 2, COMPARATOR 1, SUMMER 1, OPEN-AMP 2, MULTIPLIER 2, INVERTER 1 | |
14 | ||
15 | DATA DIVISION | |
16 | OUTPUT OUTPUT.X -xlimited | |
17 | OUTPUT OUTPUT.Y result | |
18 | COEFFICIENT.1 Factor # root(2/(gamma*m)), scaled to 0,142 10kd/Tm^3/2 | |
19 | COEFFICIENT.2 RE # Earth's orbital radius, scaled to 0,150 Tm | |
20 | COEFFICIENT.3 1/3RE # note: dependent on RE, scaled to 0,05 Tm | |
21 | ||
22 | PROGRAM DIVISION | |
23 | +1 -> COEFFICIENT.RE -> RE | |
24 | +1 -> COEFFICIENT.1/3RE -> 1/3RE | |
25 | ||
26 | # obtaining x through integration of 1, starting at 1/3RE | |
27 | +1, IC:1/3RE -> INTEGRATOR -> -x | |
28 | ||
29 | # limiting x to the upper limit of the integral RE and set x=0 if beyond | |
30 | A:-x, B:RE, GT0:-x -> COMPARATOR -> -xlimited | |
31 | ||
32 | -xlimited, 1/3RE -> SUMMER -> -(-x+1/3RE)=x-1/3RE | |
33 | ||
34 | # root of x-1/3RE | |
35 | ## first invert because the input of a root has to be negative | |
36 | x-1/3RE -> INVERTER -> -(x-1/3RE) | |
37 | ## now make sure the input is never >0 (which causes the circuit to error) | |
38 | A:-(x-1/3RE), LT0:-(x-1/3RE) -> COMPARATOR -> -(x-1/3RE)limited | |
39 | ## now calculate the root | |
40 | -(x-1/3RE)limited, OA1 -> OPEN-AMP -> root | |
41 | root, root -> MULTIPLIER -> OA1 | |
42 | ||
43 | # x/root | |
44 | -xlimited, OA2 -> OPEN-AMP -> x/root | |
45 | x/root, root -> MULTIPLIER -> OA2 | |
46 | ||
47 | # integral | |
48 | x/root -> INTEGRATOR -> integral | |
49 | integral -> COEFFICIENT.Factor -> result | |
50 | ||
51 | OPERATION DIVISION | |
52 | MODE REPEAT | |
53 | OP-TIME 111ms |