| | 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 |
projects / Analog_Engine.git / blame_incremental