This is a calculator to do common electronics calculations. It is optimized for use on the N810 Internet Tablet (which is what I use), but it will run on any computer with a python interpreter and the pygtk toolkit. (okay - so that's really a fairly tall order on windows, but its not what I built it for)

Currently the calculator has tabs for:

- Ohms Law calculations: Enter any two of Voltage, Current, Resistance, or Power, and calculate the other two.
- Capacitive Reactance calculations: Enter any two of Capacitance, Frequency, or Reactance, and calulate the other
- Resistor Codes: Select the color bands, Enter the three or four digit SMT resistor code, or the resistance value, and calculate all the rest.
- Capacitor Codes: Enter a capacitance value or 3 digit SMT code and calculate the other.
- Netlist function: Maintain a database of network lists that can be exported to PCB desing tools and SPICE simulations

All of the calculator tabs feature autoranging of values, and allows automatic adjustment of the value range. For example if the value shows 100nf, you can change the pulldown to uF and the value will recalculate as .1 uF. For more details, see the screenshots below.

Installation is simple - just browse here with your Internet Tablet, and click on: electronicscalc_2.0.0_all.deb

For full access to the project in garage, including the bug tracking, todo lists, and the source code repository. Click here

The Ohms law page allows you to calculate voltage, current, resistance, and power. Basically you can select any two values to enter, and the other two values will be calculated. You can select the dependant and independant variables by clicking on buttons to the left of the entry fields. There is logic related to how the program switches between selected and deselected buttons, but it is easiest to just click one of the buttons until the ones you want are selected. The "depressed" buttons are the dependant (calculated) values, while you will enter values for the others. In the display above, I was determining the maximum current I could put through a 5 watt.05 ohm current sense resistor.

The Capacitive Reactance page calculates Capacitance, Frequency, or Reactance. As with the Ohms Law page, select the calculated value by clicking the button with the variable name, then enter the other two values to calculate the results

The Resistor colors page calculates the value of a resistor from colors bands, or the color bands from the resistance value. It calculates three band (under 10 ohms), four band, and five band (precision) resistors. It also calculates three or four digit SMT number codes for resistance or vice-versa.

The Capacitor Codes page calculates capactor values from SMT Codes or vice-versa. Enter one and the other calculates.

The Netlist function allows the creation and maintenance of network lists (netlists) that store which parts make up a circuit, and how they interconnect. It is not quite as obvious to use as the other functions, so there is a separate netlist tutorial page here