CJS Software and Electronics Resources

Developing from an early interest in general science, I've been interested in electronics and software both from a hobby perspective and in my professional career. This site contains a range of resources such as software applications, and informative or constructional articles on electronics mostly relating to those long-standing interests.

This site was completely rebuilt in 2016 using responsive web design, and new material has been added including new software apps, and additions to many of the previously published articles.


My software pages include the following:


An easy-to-use application that keeps your data files backed up as you work, without having to manually update the backup every time. Would you like to be able to install a backup system for someone else (e.g. family member, friend, employee) who might not otherwise want to be bothered with making backups, so that it gets done automatically for them? BackupCat has been designed to satisfy those needs!

BackupCat keeps your data files continuously and automatically backed up as you work. It keeps your files backed up to a second or remote drive, runs unobtrusively in the background without slowing down other applications, automatically updating backups as your files change, and includes the ability to automatically locate common user folders when you set it up (free for personal use or evaluation)

Visual Colour Selector

This application enables you to visually preview colours from predefined palettes (e.g. CSS3, X11, wxColourDatabase, etc.) or user-defined palette files, and copy names, RGB decimal and RGB hex values to the clipboard for coding, web design etc. and is available cross-platform for Windows, Linux and macOS X.

You can create your own subset of colours from predefined palettes, or generate random colours with user-specified ranges of hue, saturation and value/luminance, and optimise them for colour separation using CIE delta-E colour separation standards.

You can view colours simulated as seen by people with colour deficiencies (protanopia, deuteranopia, and tritanopia) and generate optimised palettes accounting for colour deficiencies.

You can evaluate the contrast between light and dark colours in a filtered palette according to WCAG 2.0 (ISO/IEC 40500:2012) accessibility criteria (increasingly a requirement for government websites), with the option to account for colour deficiency, and preview image files.

Palettes can be opened and saved in X11, JASC PAL, ACO, ASE and GIMP file formats, and you can also edit individual colours.


wxLeakyBin is a graphical tool to assist in identifying even small memory leaks quickly. wxLeakyBin allows you to view system and process memory usage graphically, zoom in using a magnified scale factor, plot commit charge for individual processes as well as the system, and measure changes in memory usage and rates of change with update speeds down to 100ms intervals, 5 times faster than Task Manager.


GuidScreener is a custom GUID/UUID generator available cross-platform for Windows, Linux and macOS X, which generates RFC 4122 format GUIDs from the system generator or a high quality random number generator and allows you to preset selected digits to generate a more easily recognisable ID (e.g. C0FFEE42-31C2-478A-A6A3-97F1EBCA6256), or groups of GUIDs that will appear adjacent in a sorted list (freeware).


CCTScribe (Circuit Scribe) is a freeware circuit/schematic drawing and netlisting program capable of creating decent quality schematics and drawings and also able to export netlists for PCB layout and SPICE modelling.


WAVToCode is a freeware audio format converter that generates C code format from WAV files, enabling sound effects to be incorporated in embedded processor code.


RFProp is a freeware Windows program that calculates the radio wave propagation signal budget applicable to many kinds of VHF, UHF, microwave and satellite communications.

WinShoe IRC Client

This application can connect to multiple Internet Relay Chat (IRC) networks, and works on Windows XP, 7 and 10.

Software continued...


My electronics pages include both some articles exploring the fundamentals of electronic engineering, and some articles describing some specific constructional projects.

Theory Articles

My theory articles cover the basics of the whole spectrum of electronics from valves (tubes) to semiconductors, including their principles and practical use, which should give you a basic introduction to the subject of electronic hardware. They include the following:

  • Basics of Bipolar Junction Transistors - How semiconductor diodes and transistors work with a basic introduction to their semiconductor physics.
  • Introduction to Biasing and Load Line Analysis - Explains biasing, and describes biasing methods for various types of transistor.
  • Physical Fabrication of Transistors, from Point Contact to Planar Epitaxial - Describes the development of transistor fabrication technology that led to the main bipolar junction and field effect families of devices and chips.
  • Introduction to Thermionic Valves (Vacuum Tubes) - Describes the history and fundamental principles of valve diodes, triodes, tetrodes and pentodes.
  • Introduction to RC coupled Audio Frequency Triode Amplifiers - Describes how triode valves are used in audio frequency amplifiers stage, how multiple stages are coupled together, how this relates to field effect semiconductors, and comments on other coupling methods and valve types. Includes examples of a 3W RC coupled triode amplifier, and a 5W pentode amplifier.
  • Modelling the LM35 Temperature Sensor in SPICE - How the common LM35 temperature sensor can be simulated using a SPICE model.
  • GPS Vehicle Tracking Systems - Describes how Global Positioning Satellite (GPS) systems work and can be used for tracking vehicles.

Constructional Articles

My constructional articles include the following:

  • A versatile, expandable 4-channel Sequencing Light Controller - Describes a light sequencer designed for future expansion by means of a plug-in module, for functions such as sound-to-light.
  • A Compact Digital TV Antenna for Home Construction - Describes the design and construction of an antenna for digital TV, which suits the UK Freeview, and other systems in a similar frequency band.
  • Geiger Counter and Ratemeter - This article describes the principles and construction of a Geiger-Muller radiation monitor and counter, that I had published in Electronics Today International, February and March 1987 (as of 2016, still working perfectly).
Electronics continued...


As an extra off-main-topic bonus, I have also included various miscellaneous articles that generally have an interest in photography in common.

The subjects include the Brunel Museum and Thames Tunnel, some photographs of Chrissie Hynde at a concert by The Pretenders, photographs and diary from a visit to Albania in 1987, photographs taken in Israel and the Golan in 1989, and some collections of tram and light rail pictures including some from other contributors.

Photography continued...