Resistor Tools

Resistor Tools... To help you chose 1% values for
resistor ratios or resistor dividers.


                                                               
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Often when designing analog circuitry you'll need to use a resistor divider to reduce a voltage by a certain ratio. The trick is finding two good resistors to do it. Guess and Check by hand is not a good option with the 1% values. So, out comes a bigger hammer, courtesy of Perl.

Portions of the CGI code were liberally borrowed from Muhammad A Muquit's "upload.pl" application. All icky looking code is my own.

I haven't done much testing at all. Use at your own risk! I'd be interested to get bugs or improvements back to Alex at d n l n k dot see oh em. If you want to look at the code, do a right click on the links and chose the "save as" option. I think.

For chosing resistor values when you have a desired R1/R2 ratio: resratio.pl

For chosing resistor values when you have a desired Rb/(Ra+Rb) ratio: res1divider.pl


Here is a table of 1% resistor values.

These values seem to be somewhat of a standard. Multiply by decades to your pleasure... they seem to be solidly availiable up to about 2M.
10.0, 10.2, 10.5, 10.7, 11.0, 11.3, 11.5, 11.8, 12.1, 12.4, 12.7, 13.0, 13.3, 13.7, 14.0, 14.3, 14.7, 15.0, 15.4, 15.8, 16.2, 16.5, 16.9, 17.4, 17.8, 18.2, 18.7, 19.1, 19.6, 20.0, 20.5, 21.0, 21.5, 22.1, 22.6, 23.2, 23.7, 24.3, 24.9, 25.5, 26.1, 26.7, 27.4, 28.0, 28.7, 29.4, 30.1, 30.9, 31.6, 32.4, 33.2, 34.0, 34.8, 35.7, 36.5, 37.4, 38.3, 39.2, 40.2, 41.2, 42.2, 43.2, 44.2, 45.3, 46.4, 47.5, 48.7, 49.9, 51.1, 52.3, 53.6, 54.9, 56.2, 57.6, 59.0, 60.4, 61.9, 63.4, 64.9, 66.5, 68.1, 69.8, 71.5, 73.2, 75.0, 76.8, 78.7, 80.6, 82.5, 84.5, 86.6, 88.7, 90.9, 93.1, 95.3, 97.6