I don't accept responsibility for any harm you may do to your gear, yourself, or to someone else, armed with the knowledge from this site. I don't guarantee that the networks found by this tool are correct, or that this tool will find the best fitting network. Be sure to measure each resistor network you construct before plugging it into the circult. I also don't take responsibility for you graduating without knowing how to design or solve resistor networks.
Every now and then your next project may need a resistance value that you don't have in your stock. The possible answers to this problem:
- Dig through a bunch of nearby 10% resistors with an ohmmeter. Fails when you don't have that nearby 10% stock, also takes time to find a fitting value.
- Plug a decade box, a pot, or a trimmer. This might work, but is bulky, expensive and dangerous (accidentally turning the pot while the circuit is powered may fry your ICs). Quickly becomes impractical when you need several such resistances.
- Order the missing resistors online and wait for delivery. Now your project is on hold for days. When the resistor finally shows up, you may not have the time or inspiration that you have now. (But if you're not in a hurry, this could be the safest choice).
As you can guess already, another solution is: Build a network out of available resistors. This is cheap, safe, quick, and reasonably compact. Now the question becomes: how to design the most fitting network? Sometimes it's trivial, like obtaining 2k when you already have 1k: just use two of them in series. In many other cases though the best network is less obvious, especially if you already have a sizeable stock.
This "Resistor Network Finder" tool will help you designing the best network. All you need to do is specify your current stock and the values you are missing. The tool will then crunch through all possible networks (up to certain size), and come up with suggestions.
- Finds networks of up to 6 resistors.
- Searches all possible topologies, including bridges.
- Allows to specify your stock using standard series, range, gaps and extras.
- Configurable target error (set it to 0 to see the closest network possible).
- Supports specifying a list of target resistances, shows the optimal networks for each target in a single table.
- Shows schematic of each network found.
- Can find a single additional (non-stocked) resistance value, that would be the most helpful for obtaining specified target resistances.
2016-06-14 - Resistor Network Finder is first made public.
Similar tools and calculators
Listed in the order of general usefulness (subjective).
- Equivalent Parallel Resistor Network Finder - Finds parallel networks of up to 4 resistors. Flexible stock configuration.
- Resistor calculator (series and parallel) - Finds networks of 2 resistors. Stock is selectable between E12, E24 and E96.
- Resistor finder - Finds networks of 2 resistors. Stock series can be selected from E6 to E192.
- WolframAlpha - Finds networks of up to 3 E6 resistors, has no configuration for stock or anything else.
- Parallel Resistor Combination Calculator - Finds parallel network of 2 resistors, from a configurable stock of up to 10 values.
- Combine preferred numbers - Funds serial combinations of up to 3 values. Stock series is selectable between E6, E12 ad E24.
|© 2016 Kirill Kryukov
Available under the CC BY 4.0 License