HP 35S: Resistors in Series or Parallel (Portred from HP-33E) - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: HP 35S: Resistors in Series or Parallel (Portred from HP-33E) (/thread-252836.html) HP 35S: Resistors in Series or Parallel (Portred from HP-33E) - Eddie W. Shore - 10-13-2013 Resistors in Series or Parallel Source: HP-33E Student Engineering Applications, 1978 Original Calculator: HP-33S Credit to Hewlett Packard Company Ported to HP 35S by Eddie Shore, 10/10/2013 Instructions: 1. For each group of parallel or series resistors: press XEQ R. 2. At the Mode Prompt (INPUT M), enter 0 R/S for Parallel Resistors, 1 R/S for Series Resistors 3. Enter resistor values (assumed to be in Ohms) then press R/S. 4. To find the total, press XEQ R016. 5. Optional: Store the result in a variable for future use, as long is it not R. Parallel Resistors: total resistance = 1/( 1/R1 + 1/R2 + ... ) Series Resistors: total resistance = R1 + R2 + ... ```R001 LBL R R002 0 R003 STO R R004 SF 10 // press Left Shift, Flags, SF, decimal point, 0 R005 0=PAR 1=SER // equation R006 PSE R007 CF 10 // press Left Shift, Flags, CF, decimal point, 0 R008 INPUT M R009 R/S R010 RCL M R011 x=0? R012 XEQ R024 R013 R-down R014 STO+ R R015 GTO R009 R016 RCL R // total resistance R017 RCL M R018 x=0? R019 XEQ R024 R020 CLx R021 STO M R022 R-down R023 RTN R024 R-down R025 1/x R026 ENTER R027 RTN ``` Re: HP 35S: Resistors in Series or Parallel (Portred from HP-33E) - Harald - 10-13-2013 I don't quite see the point of the program. I ususally do this: R1 1/x R2 1/x + 1/x or on the WP34S: R1 Enter R2 g || I am probably missing something... Re: HP 35S: Resistors in Series or Parallel (Portred from HP-33E) - R. Pienne - 10-14-2013 It's interesting to see a (ported) program from 1978, thanks to Eddie. In those days programming a calculator was such a novelty that I think HP just wanted to show off the input/looping features at every opportunity. Of course, series resistances can be much more easily calculated by addition, and parallel by a much simpler program: LBL R 1/x x<>y 1/x + 1/x RTN. That was as true in 1978 as it is now.