If you like to rely on the web to do your electronics and computer math, you’ll want to bookmark FxSolver. It has a wide collection of formulae from disciplines ranging from electronics, computer science, physics, chemistry, and mechanics. There are also the classic math formulations, too.
When you first hit the page you’ll see a message that your solver is currently empty. There’s a sidebar on the left and a search box. To start, try searching for a few things you know you’ll want to use. We did Ohm’s law and a voltage divider, winding up with a custom page of calculators.
The calculators can take values as a table or in a spreadsheet-like format. You can save the worksheet and restore it later. If you provide a list of values, it can plot the results for you. For example, the graph below is what happens when you vary a resistor around 50 ohms across 25V.
The arrow on the left of a graph opens a menu where you can customize the plots. Even though the drop down for units showed mA (milliamps) and MA (megaamps), every time we tried for milliamps, it reverted to mega amps. On the plus side, you can group the calculators together and show or hide groups.
What was really interesting, though, is that you can create your own formula, if you like. We didn’t see one for the resonant frequency of an LC circuit, for example, so we cooked one up.
Once you create the formula, you can have it solve for any of the values. Another thing of interest is you can link the result of one formula to another. However, experimenting with that led to some odd results. Even after disconnecting the formulas there seemed to be something still going on.
We couldn’t see a way, though, to create a formula that would easily create a list, although maybe we just missed it. For example, it would be nice to have a formula to generate frequencies from 100 Hz to 10000 Hz in steps of 100 Hz instead of having to type out the whole list. Then you could ink that formula to another. On the plus side, in spreadsheet mode, you can copy data from a spreadsheet into the calculator.
This isn’t going to compete with Wolfram Alpha, but it is still useful. Of course, if you want to just dump your old TI calculator to the web, there’s a way to do that, too.