Impedance of a Ladder Network
Description
Origin: HP-34C Student Engineering Applications, August 1979, p. 11
This program computes the input impedance of an arbitrary ladder network. Elements are added one at a time starting from the right. This first element must be in parallel
Suppose we have a network whose input admittance is Yin. Adding a shunt R, L or C, the input admittance becomes:
Yin + (1/Rp + j0)
Ynew = Yin + (0 - j/(ωLp))
Yin + (0 + jωCp)
Adding a series R, L or C, we have:
(1/Yin + (Rs + j0))-1
Ynew = (1/Yin + (0 + jωLs))-1
(1/Yin + (0 - j/(ωCs))-1
This program converts this admittance to an impedance for display.
Note: An erroneous entry may be corrected by entering the negative of the incorrect value.
Example:
f = 4 Mhz

4 EEX 6 A 50 GSB 1 → 50.0000 (|Zin|, ohms)
2400 EEX CHS 12 GSB 3 → 15.7362 (|Zin|, ohms)
x↔y → -71.6559 (∠Zin, deg)
2.56 EEX CHS 6 B GSB 2 → 49.6509 (|Zin|, ohms)
x↔y → 84.2754 (∠Zin, deg)
796 EEX CHS 12 GSB 3 → 497.6942 (|Zin|, ohms)
x↔y → 0.9840 (∠Zin, deg)
Program Resources
Labels
Name |
Description |
|
Name |
Description |
|
A |
Store frequency |
|
4 |
# - internal use - |
|
B |
Next element is added in series |
|
5 |
# - internal use - |
|
1 |
Add resistance R [ohms] |
|
6 |
# - internal use - |
|
2 |
Add impedance L [henrys] |
|
9 |
# - internal use - |
|
3 |
Add capacity C [farads] |
|
|
|
|
Storage Registers
Name |
Description |
|
0 |
ω |
|
1 |
Re |
|
2 |
Im |
|
Flags
Program
Line |
Display |
Key Sequence |
|
Line |
Display |
Key Sequence |
|
Line |
Display |
Key Sequence |
|
000 |
|
|
|
022 |
42,21, 5 |
f LBL 5 |
|
044 |
40 |
+ |
|
001 |
42,21,11 |
f LBL A |
|
023 |
45 0 |
RCL 0 |
|
045 |
33 |
R⬇ |
|
002 |
42 34 |
f REG |
|
024 |
20 |
× |
|
046 |
40 |
+ |
|
003 |
2 |
2 |
|
025 |
15 |
1/x |
|
047 |
43 33 |
g R⬆ |
|
004 |
20 |
× |
|
026 |
16 |
CHS |
|
048 |
43, 6, 0 |
g F? 0 |
|
005 |
43 26 |
g π |
|
027 |
0 |
0 |
|
049 |
32 4 |
GSB 4 |
|
006 |
20 |
× |
|
028 |
34 |
x↔y |
|
050 |
44 1 |
STO 1 |
|
007 |
44 0 |
STO 0 |
|
029 |
22 9 |
GTO 9 |
|
051 |
34 |
x↔y |
|
008 |
43, 5, 0 |
g CF 0 |
|
030 |
42,21, 3 |
f LBL 3 |
|
052 |
44 2 |
STO 2 |
|
009 |
43 32 |
g RTN |
|
031 |
43, 6, 0 |
g F? 0 |
|
053 |
34 |
x↔y |
|
010 |
42,21,12 |
f LBL B |
|
032 |
22 5 |
GTO 5 |
|
054 |
32 4 |
GSB 4 |
|
011 |
43, 4, 0 |
g SF 0 |
|
033 |
42,21, 6 |
f LBL 6 |
|
055 |
43, 5, 0 |
g CF 0 |
|
012 |
43 32 |
g RTN |
|
034 |
45 0 |
RCL 0 |
|
056 |
43 1 |
g →P |
|
013 |
42,21, 1 |
f LBL 1 |
|
035 |
20 |
× |
|
057 |
43 32 |
g RTN |
|
014 |
15 |
1/x |
|
036 |
0 |
0 |
|
058 |
42,21, 4 |
f LBL 4 |
|
015 |
43, 6, 0 |
g F? 0 |
|
037 |
34 |
x↔y |
|
059 |
43 1 |
g →P |
|
016 |
15 |
1/x |
|
038 |
42,21, 9 |
f LBL 9 |
|
060 |
15 |
1/x |
|
017 |
0 |
0 |
|
039 |
45 2 |
RCL 2 |
|
061 |
34 |
x↔y |
|
018 |
22 9 |
GTO 9 |
|
040 |
45 1 |
RCL 1 |
|
062 |
16 |
CHS |
|
019 |
42,21, 2 |
f LBL 2 |
|
041 |
43, 6, 0 |
g F? 0 |
|
063 |
34 |
x↔y |
|
020 |
43, 6, 0 |
g F? 0 |
|
042 |
32 4 |
GSB 4 |
|
064 |
42 1 |
f → R |
|
021 |
22 6 |
GTO 6 |
|
043 |
43 33 |
g R⬆ |
|
065 |
43 32 |
g RTN |
|