Simple parallel circuit problem

[Gerson W. Barbosa]

(08-28-2015 01:47 PM)Dave Frederickson Wrote:  

(08-28-2015 05:52 AM)Gerson W. Barbosa Wrote:  Only a TI-57 here, but I had a TI-51-III in 1982, replaced three months later by a TI-59 due to a faulty keyboard. The TI-59 worked flawlessly for about six months before eventually being stolen. The replacement HP-15C is still working to date :-)

I suspect others missed the joke, too. My calculators are the old Excel spreadsheet resistor calculators written by a guy at TI.

Quote:PARALLEL RESISTOR CALCULATOR, Version 1

By Bruce Carter, Texas Instruments Applications

This utility solves a common engineering problem - how to reach a target
resistance with two resistors in parallel. It assumes that you are free to choose
one of the two resistors that will be put in parallel - called the "seed" resistor.
The spreadsheet will then choose the closest resistor that, in parallel with
the seed resistor, will produce the target resistance. You have the choice of
using 1% resistors, or 5%.

I did follow the links and noticed the TI reference. I even wondered about the connection to TI calculators. Sarcasm sign needed here sometimes :-)

I usually solve the first problem on the WP 34S by following this procedure:

1000 ENTER 50 +/- g || --> -52.6315789474

Then I manually select one from the tables (or from my spare parts box), closest positive value, of course :-)

1000 ENTER 52.3 g || --> ~ 49.7 ohms.

Gerson.

P.S.: I love the || function on the WP-34S. Thanks, Walter!