Here is a zipped Excel spreadsheet that gives the resultant resistance of 2 resistors connected in series or in parallel. It covers one decade, but other decades can be inferred by shifting the decimal points.

It is best printed in landscape.

Len

Attached Files

res_comb.ZIP (23.5 KB, 58 views)

 

Did anyone find this useful?

 

I did not check it out but I can say that in the time it takes to look up a value in a table, I can calculate the result either in my head or on a calculator in much less time. How about an N (parallel) resistor calculator in excel? With many resistors, this would save some time.

 

Speaking of references, I made a resistor value calculator with Excel, some VB programing, and some artwork. I use this pretty often as it helps me make the constant correlation between the colors and the values of the resistors. Most often, it is best to memorize the "conversions" so that you're not chained to a reference, but this nifty little spreadsheet helps me memorize the color combinations and their conversions. It's also good for finding values quickly if you're sifting through the ol' junk box.

The excel spreadsheet uses macros, so you will receive a warning when opening the file. THERE ARE NO MALICIOUS MACROS WITHIN THIS FILE!!! I GIVE YOU MY WORD. The macros are there for the buttons and the various visual basic commands only! If you're still leary, scan it with your virus software before opening.

I've protected the workbook without a password, just to eliminate the accidental movement of objects etc. Feel free to adjust to your tastes. Just click on Tools, then protection, then unprotect workbook. no password is needed, just click "OK".

I've tried to make the process as visual as possible, accounting for those who are colorblind by adding text. The rest is self explanatory. Let me know what you think.

I'm planning to make similar pages for Inductor color codes, and capacitor markings, for our electronic newby friends.

Attached Files

Resistor_Value_Calculator.zip (52.5 KB, 36 views)

 

Yeah, but did you miss the point? I think the point of the table is, given a goal (odd resistor value), what two standard values can you use to get there?
Having said that, the problem with using 5% resistors to get intermediate values is that you may still be off by 5%.

 

Hi Johnson,

I liked the Excel Calculator.
Bit clunky,
but i like little progs that look like games.

I didn't like the Excel surround,
maybe it could be done in HTML ... ?

And also, if it's no trouble, could you add
another digit-band ... more and more of my
resistor collection are now four bands of colour.

i would like to put it as a function on to my website.
(with your permission)

Cheers, John

 

I wrote a Turbo Pascal DOS program years ago, you give it the value you want and it gives you the two nearest prefered values to parallel to make it - along with the percentage of error.

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