HP 15C: Stair Calculations

HP 15C:  Stair Calculations

Variables:

Input: 

R0 = Riser Height (RH)

R1 = Run

R2 = Rise

Store values in R0, R1, and R2 before running the program.

Output:

R3 = number of stairs (S)

R4 = Treadwidth (TW)

R5 = Stringer Length (ST)

Formulas Used:

S = int(rise/RH) – 1

TW = run/S

ST = S * √(RH^2 + TW^2)

Step	Key	Key Code
001	LBL C	42, 21, 13
002	RCL 2	45, 2
003	RCL÷ 0	45, 10, 0
004	INT	43, 44
005	1	1
006	-	30
007	STO 3	44, 3
008	R/S (S)	31
009	1/X	37
010	RCL* 1	45, 20 ,1
011	STO 4	44, 4
012	R/S  (TW)	31
013	X^2	43, 11
014	RCL 0	45, 0
015	X^2	43, 11
016	+	40
017	√	11
018	RCL* 3	45, 20, 3
019	STO 5	44, 5
020	RTN	43, 32

Example:

R0 = 7 inches (riser height)

R1 = 56 inches (run)

R2 = 80 inches (rise)

Results:

R3 = 10 (number of stairs)

R4 = 5.6 inches (treadwidth)

R5 ≈ 89.6437 inches (stringer)

This blog is property of Edward Shore.  2016

HP 15C: Reactance Chart Solver

HP 15C: Reactance Chart Solver

Source:  HP-65 E.E. PAC 1.  Hewlett Packard.  September 1974.  pg. 8-9

Equation:

2 * π * f * √(L*C) = 1

Variables:

R0 = f = Resonant Frequency (Hz)

R1 = L = inductance (henrys)

R2 = C = capacitance (farads)

Instructions:

Enter the known values in each of the variables.  Enter the number of the variable to be solved in register I ( [ STO ] [ TAN ] (I) ).  To solve, enter a range, and press [ f ] [ ÷ ] (SOLVE), [ y^x ] (D). (*or whatever label you assigned this program to)

Program:

Step	Key	Key Code
001	LBL D	42, 21, 14
002	STO (i)	44, 24
003	2	2
004	π	43, 26
005	*	20
006	RCL* 0	45, 20, 0
007	RCL 1	45, 1
008	RCL* 2	45, 20, 2
009	√	11
010	*	20
011	1	1
012	-	30
013	RTN	43, 32

Example:

L = R1 = 2.5 H, f = R0 = 60 Hz.  Calculate C (R2).  Store 2 in RI.

Result:  R ≈ 2.8145 E-06  (use range 0 to 1)

This blog is property of Edward Shore. 2016