Voltage Divider Resistor Picker

Hi, There are 480,000 different combinations of standard 1% resistor values. If you need 2.75 volts from a 5.00 volt reference, which of those 480,000 pairs will give you the closest result?

For this example there are 9 resistor pairs that will get you to within

0.5%, but one resistor pair will get you within 0.15%. Only 1 out of 480,000 combinations is the best pair!!

The Best Pair II resistor calculator program will calculate and display the twenty one best voltage divider resistor pairs, as well as the error voltages, percent error, "Perfect R2" and "R Thevenin" values. Results can be scaled to any decade of course.

BestPair has been upgraded to Best Pair II. If you are interested you can get it with instant download delivery here -->

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Thanks for looking.

Cheers, Tim

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Reply to
Tim
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Save the 5$ and comparable software for free :

goto :

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and download :
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Rene

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Reply to
Rene Tschaggelar

...then there's the old standby by Terry Harris at RSW's site (Nearest; Series; Parallel; Divider): http://72.14.207.104/search?q=cache:ULaUZ9H9IGQJ:

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Reply to
JeffM

Updated :-

"It now supports E192 range and supports selection from mixed ranges. It no longer rounds input values to 3 significant digits. It can run multiple instances (which is more a bug than a feature)."

at

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Reply to
nospam

Yes - Please download and try the free program.

If you find you do not like it please take a closer look at BestPair II -->

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In seven years BestPair I had ZERO unsatisfied users.

You get what you pay for.

Thanks for looking.

Cheers, Tim

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Reply to
Tim

The number of times that I've had to select values from a range like that, I've done it "by hand" with a spreadsheet. ;-)

Although, it would be kind of a fun programming project - maybe I'll put up a "divider calculator" web page. ;-)

Cheers! Rich

Reply to
Rich Grise

Like these?

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Reply to
JeffM

If they are 1% resistors, then NO pair will be within 0.15% !!!

Mark

Reply to
redbelly

Typically 1% resistors are within 0.15% or so.

Nothing wrong with trying to get closer to the ideal values on analog stuff.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

This isn't unqualifiedly true. Some pairs MAY be within 0.15%; some may not. What you want to say is that there is no guarantee that any particular pair will be within 0.15% when built with real 1% resistors.

Reply to
The Phantom

Thoses calculators are great but where can I find a list of commercially available resistances ? Thanks :-)

Reply to
:-)

Googling revealed a nice web page at

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In general, resistors are available in various series depending on the tolerance. The values repeat in each decade, and the tighter the tolerance, the more values in the series. For instance, the 20% series contains 10R,

15R, 22R, 33R, 47R, 68R, and then in the next decade 100R, 150R, ... and so forth. These days, one mostly finds 1% and 5% resistors. Technically the 1% series has different values than the 5% series (for instance, the 5% series contains the value 2.2, where 1% contains 2.21), but some manufacturers make the 5% series values available in 1% tolerance for the sake of continuity with older designs.

Any distributor's catalog will list resistance values. For instance, in Mouser's current catalog, take a look at

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Reply to
Walter Harley

My fav:

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A backup:

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(Assuming you can get them to display in your browser; neither of these turkeys knows how to construct a proper HTML page.

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764 errors) . . BTW, when you respond, it's OK to delete 18 of the previous 19 blockquotes in the thread

--and to trim out anything which YOU aren't addressing.

Reply to
JeffM

Thanks :-)

Reply to
:-)

Nice one Thanks !

Reply to
:-)

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