**These programs are distributed in the hope that they will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.**

**Most are made available under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, but see the License conditions for each individual program.**

These programs are in the form of Web Widgets which execute within a web browser. They are coded in HTML, CSS and javascript.

In many cases the files may also be downloaded for local use in a web browser. This may require modification of the browser's security settings.

The "images" below are **live web widgets** which are executing on this page.

Information about most widgets can be obtained by clicking on the **HELP buttons** or on the **blue help balloons**.

Many of the simple calculators require the user to enter data and then **press the RETURN or ENTER key**.

NetCalc is broadly based on the program NETCALC by Ian White. NETCALC was described by Ian as a simple impedance calculator for working out Radio Frequency network design ideas.

Direct Link or download the files for local use in your browser.

Direct Link for browser (wide) version

This is a special purpose calculator which performs simple 3-phase alternating
current calculations.

Given three of the four quantities voltage, current, power factor and power, the Widget
calculates the value of the fourth.

Two formulae are used, one for line voltages and currents, the other for phase voltages
and currents.

Direct Link or download the files for local use in your browser.

Attenuator is a special purpose calculator for the design of passive resistive attenuators
and impedance matching circuits.

The Widget can assist in the design of PI-network, T-network, BT-network, B-network
and L-network attenuators and impedance matching circuits.

It can perform single calculations and (in symmetric cases) generate tables for later use.

Direct Link or download the files for local use in your browser.

This is a special purpose calculator which calculates the properties of a single-layer air-spaced coil. Given three parameters, the Widget calculates the value of a fourth.

Direct Link or download the files for local use in your browser.

The L-Section Calculator is a special purpose calculator which computes the component values for L-Section impedance matching filters.

Direct Link or download the files for local use in your browser.

This is a special purpose calculator for the analysis of LCR resonant circuits.

Direct Link or download the files for local use in your browser.

This is a Morse code practice program. The sending speed is user settable (Farnsworth method) between 5 and 20 wpm. Text files and texts can be dragged onto the main window and are sent after a two second delay. There are ten user settable "standard" texts which are sent by pressing a hotkey. The keyboard can be used to send Morse code. The Widget displays the characters (but not the Morse patterns) as they are sent.

It uses/requires HTML5 Audio and File APIs.

Direct Link or download the files for local use in your browser.

This is a special purpose calculator which performs simple calculations using Ohm's Law. Given any two of the four quantities - voltage, current, resistance or power - the Widget calculates the values of the other two.

Direct Link or download the files for local use in your browser.

The Resistors Calculator is a special purpose calculator which can be used to decode the colored bands on resistors (and some small capacitors).

Direct Link or download the files for local use in your browser.

The Series to Parallel Converter is a special purpose calculator which converts between very simple Series and equivalent Parallel circuits.

Direct Link or download the files for local use in your browser.

The Steampunk Resistors Calculator is a special purpose calculator which can be used to decode the colored bands on resistors (and some small capacitors).

Direct Link or download the files for local use in your browser.

This is a special purpose calculator which performs simple transmission line calculations. Given three line parameters, the Widget calculates the value of a fourth. Two formulae are used, one for coaxial cable, the other for parallel line.

Direct Link or download the files for local use in your browser.

This is a special purpose calculator which performs simple wiring calculations for copper wires used in low voltage circuits.
Given three of the four quantities circuit length, current, wire cross section and voltage drop, the Widget calculates the value of the
fourth.

WARNING: The calculator was designed to calculate the voltage drop in low voltage (12/24 volt) marine circuits where the voltage drop
due to long wire circuits is more often a problem than the current carrying capacity of the wires.
No attempt has been made to ensure that the results of any of the calculations conform to current electrical codes,
such as the NEC or IEC codes. Users must check these and other safety matters for themselves.

The user can choose to work in SI units or USA units.

Direct Link or download the files for local use in your browser.

Last updated Wednesday, June 17, 2020.