The Museum of HP Calculators
The Museum of HP Calculators
This program is Copyright © 1978 by Hewlett-Packard and is used here by permission. This program was originally published in "HP-33E Student Engineering Applications".
This program is supplied without representation or warranty of any kind. Hewlett-Packard Company and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.
This program calculates the total resistance of a group of resistors arranged in parallel or in series.
Formulas used:
Resisters in series: RT = R1 + R2 + R3 ... + Rn Resisters in parallel: RT = 1/(1/R1 + 1/R2 + 1/R3 ... + 1/Rn)
Note that this program can be used for summing capacitors in parallel or series instead of resisters. For series capacitors, use the instruction for parallel resistors. For parallel capacitors, use the instructions for series resisters.
Several more advanced programs for circuit analysis may be found in: Anderson, L.H. "Calculator-Aided Circuit Analysis," Ham Radio Magazine, pp. 38-46, October 1977. Although written for the HP-25, they will work equally well on the HP-33E/C.
Step |
Instructions |
Input Data/Units |
Keys |
Output Data/Units |
1 |
Enter program |
|||
2 |
Initialize |
|
f REG f PRGM |
|
3 |
a) Set for parallel resistors or |
|
R/S |
0.0000 |
| b) Set for series resistors |
|
GSB 03 |
1.0000 |
|
4 |
Optional: Retrieve last RT for use in next calculation. |
|
Roll dn |
Previous RT |
5 |
Input individual resistor values (Repeat until all resistors have been input.) |
Ri |
R/S |
|
6 |
Calculate total resistance of the group |
|
GSB 12 |
RT, ohms |
7 |
Optional: Store RT for use in next calculation |
RT |
STO 2 |
|
8 |
Go to step 3a or 3b for next group. |
|
Determine the total resistance from A to B.
Keystrokes Display Comment
f REG f PRGM
Group 1: R/S 0.0000 Parallel mode
680 R/S 120 R/S
GSB 12 102.0000 R1, ohms
Group 2: GSB 03 1.0000 Series mode
Roll dn 102.0000 Retrieve R1
R/S 330 R/S
680 R/S
GSB 12 1,112.0000 R2, ohms
Group 3: R/S 0.0000 Parallel mode
Roll dn 1,112.0000 Retrieve R2
R/S 220 R/S
GSB 12 183.6637 R3, ohms
STO 2 Save R3
Group 4: R/S 0.0000 Parallel mode
680 R/S 470 R/S
GSB 12 277.9130 R4, ohms
(Total R)
GSB 03 1.0000 Series mode
Roll dn 277.9130 Retrieve R4
R/S RCL 2 R/S
GSB 12 461.5767 RT, ohms
LINE CODE KEYS 00 f CLEAR PRGM 01 0 0 02 13 04 GTO 04 03 1 1 04 23 0 STO 0 05 74 R/S 06 24 0 RCL 0 07 15 71 g X=0 08 12 20 GSB 20 09 22 Roll dn 10 23 51 1 STO + 1 11 13 05 GTO 05 12 24 1 RCL 1 13 24 0 RCL 0 14 15 71 g X=0 15 12 20 GSB 20 16 34 CLx 17 23 1 STO 1 18 22 Roll dn 19 13 00 GTO 00 20 22 Roll dn 21 15 3 g 1/x 22 31 ENTER 23 15 12 g RTN
R0 Code: 0 or 1 R1R,
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