Showing posts with label rake wall. Show all posts
Showing posts with label rake wall. Show all posts

Friday, December 23, 2016

Fun with HP 71B IV

Fun with HP 71B IV

For the previous entries:

Links to other HP 71B Programs:
Fun with the 71B:
http://edspi31415.blogspot.com/2012/06/fun-with-hp-71b.html
Fun with the 71B III:


Rake Wall

The program RAKEWALL calculates:

*  The positions and lengths of studs on a rake wall
*  Angle of the incline




Program RAKEWALL
192 Bytes, 12/22/2016

10 DESTROY B,R,L,N,A
15 DESTROY I,T,O
50 INPUT “BASE:”; B
52 INPUT “RISE:”; R
54 INPUT “RUN:”; L
56 INPUT “O.C. :”; S
74 N = INT(L/S)
76 DEGREES
78 T = ATAN(R/L)
80 DISP “ANGLE =”; T; “°”  @ PAUSE
90 FOR I=L TO 0 STEP –S
92 A = I*TAN(T)+B
94 DISP I; “, “; A  @ PAUSE
96 NEXT I
98 DISP 0; “, “; B

Notes:
Degree symbol (°):  [ g ], [RUN] (CTRL), [ A ]

Example: (amounts are in feet)
BASE:  4
RISE:  3
RUN:  6
O.C.:  16/12  (1 foot, 4 inches)

Output: 
ANGLE = 26.5650511771 °
(Position from where the incline meets the base, length of studs)
6, 7
4.66666666667, 6.33333333334
3.33333333334, 5.66666666667
2.00000000001, 5
0.66666666668, 4.33333333334
0,  4


Automotive Cylinders:  Calculating Displacement and Piston Speed

The program supplies default values which can be accepted or changed.



Program AUTOCYN
217 Bytes, 12/22/2016

10 DESTROY N,B,S,R,E,P
15 INPUT “# CYLINDERS:”,  “6”; N
20 INPUT “BORE (IN):”, “4”; B
25 INPUT “STROKE (IN):”, “4”; S
30 E = PI/4 * B^2 * S * N
35 INPUT “RPM:”; R
40 P = S * R / 6
45 DISP “ENGINE DISPLACEMENT =” @ WAIT 1
50 DISP E; “ IN^3” @ PAUSE
55 DISP “PISTON SPEED =” @ WAIT 1
60 DIPS P; “FPM”

Example 1:
N = 6 cylinders, B = 4 in, S = 4 in, RPM = 3500
Output:  E ≈ 301.59290 in^3, P ≈ 2333.33333 FPM

Example 2:
N = 6 cylinders, B = 4 in, S = 3 in, RPM = 4500
Output:  E ≈ 226.19467 in^3, P = 2250 FPM

Right Triangle Solver

The program RIGHTTRI is a solver for the sides A, B, and C.  To solve for the third side, the desired side needs to have a 0 value, while the other two sides have non-zero values.  Each time a solution is found, the values of A, B, and C are reset (set to 0).



Program RIGHTTRI
502 Bytes, 12/22/2016

10 DESTROY A,B,C,Z$
11 ! LOOP
12 DISP “A, B, C, Solve, Exit”
14 DELAY 0, 0
16 Z$ = KEY$
18 IF Z$ = “A” THEN 30
20 IF Z$ = “B” THEN 40
22 IF Z$ = “C” THEN 50
24 IF Z$ = “S” THEN 60
26 IF Z$ = “E” THEN 96
28 GOTO 12
30 INPUT “A = “; A
32 GOTO 12
40 INPUT “B = “; B
42 GOTO 12
50 INPUT “C = “; C
52 GOTO 12
60 IF A=0 AND B AND C THEN 62 ELSE 70
62 S=SQR(C^2-B^2) @ Z$ = “A”
64 GOTO 90
70 IF A AND B=0 AND C THEN 72 ELSE 80
72 S=SQR(C^2-A^2) @ Z$ = “B”
74 GOTO 90
80 IF A AND B AND C=0 THEN 82 ELSE 86
82 S=SQR(A^2+B^2) @ Z$ = “C”
84 GOTO 90
86 DISP “MUST HAVE ONE 0” @ BEEP @ WAIT .5
88 GOTO 10
90 DISP Z$; “ = “; S @ PAUSE
92 GOTO 10
94 DISP “DONE”

Notes:

The line of IF A=0 AND B AND C… tests whether A is zero, B and C are non-zero.  You can test whether a variable is non-zero by just typing the variable in an IF condition.

The function SQR is the square root function of the HP 71B.

Anything following an exclamation point (!) is a comment.


Basic Bridged-T Notch Filter

The program NOTCH calculates the required capacitor and resistor to null out an undesired frequency.

Inputs:  inductance (H), frequency to nullified (Hz), resistance of the required coil (Ω)



Source:  Rosenstein, Morton.  Computing With the Scientific Calculator Casio: Tokyo, Japan.  1986.  ISBN-10: 1124161430

Program NOTCH
244 Bytes, 12/22/2016

10 DESTROY L,F,I,C,R
20 DISP “INDUCTANCE” @ WAIT 1
22 INPUT “in H: “; L
24 DISP “FREQUENCY” @ WAIT 1
26 INPUT “in Hz: “; F
28 DISP “COIL’S RESISTENCE” @ WAIT 1
30 INPUT “in Ω: “; I
40 C = 1/(2 * PI^2 * F^2 * L)
42 R = (PI * F * L)^2 / I
44 DISP “NOTCH CAPACITOR” @ WAIT 1
46 DISP C; “ F” @ PAUSE
48 DISP “NOTCH RESISTENCE” @ WAIT 1
50 DISP R; “ Ω”

Notes:
Capital Omega Character (Ω):  [ g ], [RUN] (CTRL), [ Q ]

Example:   L = 0.12 H, F = 1170 Hz, Coil Resistance = 30 Ω
Output: 
NOTCH CAPACITOR ≈ 3.08402 * 10^-7 F
NOTCH RESISTENCE ≈ 6485.04070 Ω


Differential Equations and Half-Increment Solution, Numerical Methods

The program HALFDIFF solves the numerical differential equation

d^2y/dt^2 = f(dy/dt, y, t)  given the initial conditions y(t0) = y0 and dy/dt (t0) = dy0

In this notation, y is the independent variable and t is the dependent variable.

The Method

Let C = f(dy/dt, y, t).  Give the change of t as Δt.

First Step:

With t = t0:
h_1/2 = dy0 + C * Δt/2
y1 = y0 + dy0 * Δt

Loop:

t = t0 + Δt
h_I+1/2 = h_I-1/2 + C * Δt
y_I+1 = y_I +h_I+1/2 * Δt

Repeat as many steps as desired.


Source:  Eiseberg, Robert M.  Applied Mathematical Physics with Programmable Pocket Calculators  McGraw-Hill, Inc:  New York.  1976.  ISBN 0-07-019109-3

Program HALFDIFF
250+ bytes, 12/22/2016

Edit f(A,Y,T) at line 5 where
A = y’(t), Y = y(t),  T = t

5 DEF FNF(A,Y,T) = insert function y’(t), y(t), and t here
10 DESTROY A,Y,D,N,H,T
12 RADIANS
20 INPUT “dY/dX (0) = “, “0”; A
22 INPUT “Y(0) = “, “0”; Y
24 INPUT “DELTA T = “,”1”; D
26 INPUT “TMAX = “,”5”; N
28 T = D
44 H = A + FNF(A,Y,T) * D/2
48 Y = Y + H * D
50 DISP D; “, “;  Y @ PAUSE
70 FOR I = 2 * D TO N STEP D
72 T = I @ A = H
76 H = H + FNF(A,Y,T) * D
78 Y = Y + H * D
80 DISP I; “, “; Y @ PAUSE
82 NEXT I

Example:  y’’(t) = y’(t) + 2 *  t with y’(0) = 0, y(0) = 1, Delta t = 1, Max t = 6
FNF(A,Y,T) = A + 2 * T

Results:

T
Y
1
2
2
8
3
26
4
70
5
168
6
376


  
This blog is property of Edward Shore, 2016.





Saturday, December 3, 2016

TI-84 Plus: Rake Wall

TI-84 Plus:  Rake Wall

The program RAKEWALL calculates:

*  The positions and lengths of studs on a rake wall
*  Angle of the incline

Adding Illustration

I wanted to do something different and present an illustration rather than just text answers.  What is nice of the TI-84 Plus (and really the TI-8x family extending back to the TI-81) is that the programming language allowing for easy transition between modes (home, graphing, matrix editing, table, etc.).  With RAKEWALL, I not only display text answers, but a visual of how the rake wall is laid out. 

Sometimes the best way to present information is through visuals, not just text.  I want to further explore this whenever it is warranted.

TI-84 Plus Program RAKEWALL



Input:  Rise, Run, O.C. (on center spacing).   RAKEWALL does not specify units, keep that in mind.  Use consistent units.  As a reminder, 12 inches is 1 foot.

Output:  Angle (in Degrees), stud spacing stored in list L1, stud lengths stored in list L2.  The program ends on the graph screen.  Press [ trace ] to see the values.  X is the length from the where the incline and base meet to the stud, Y is the stud length.

Please note that results are exact and not rounded (i.e. to the nearest 1/16th).

Program:
"EWS 2016-12-01"
ClrDraw
Degree
Input "RUN:",L
Input "O.C. SPACING:",S
Input "BASE:",B
Input "RISE:",R

seq(X,X,L,0,­-S)→L1
tan^-1(R/L)→θ

L1*tan(θ)+B→L2
augment(L1,{0})→L1
augment(L2,{B})→L2

Disp "ANGLE:",θ
Disp "NUMBER OF STUDS:",dim(L1)-2
Disp "(L1: DIST. FROM SHORT PT."
Disp "L2: STUD LENGTH)"
Pause

PlotsOff
PlotsOn 1
Plot1(xyLine,L1,L2)

­0.5→Ymin
B+R+.5→Ymax
­.5→Xmin
L+.5→Xmax

For(I,1,dim(L1))
Line(L1(I),0,L1(I),L2(I))
End
Line(0,0,L,0)
Line(L,0,L,B)

DispGraph

Example:

Run:  6 feet
O.C.:  1 foot 6 inches, or 16/12 inches
Base:  6 feet
Rise:  5 feet



This program was inspired by the Calculated Industries Construction Master 5 calculator.  I am thinking about purchasing their Construction Pro calculator (most likely the app). 

Happy December!

Eddie

This blog is property of Edward Shore, 2016.



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