Electronics Assistant

Electronics Assistant is a Windows program that performs electronics-related calculations. It includes a resistor colour code calculator, resistance, capacitance and power calculations and more. Details of calculations can be saved or printed. It provides all the functions found in the calculators section of this site and more in a stand-alone user 
friendly program.



Version 4.1 includes the following new features:

• Updated user interface
• Extra calculators for inductance and frequency
• Calculation of nearest preferred resistor values with a choice of 5 series from E12 to E192
• Links to open Windows Calculator and up to 3 user-defined programs from Electronics Assistant
• Information panels can be toggled on or off to save space when not required
• Built-in automatic new version update check
• Various bug fixes and enhancements

Version 4.1 also fixes a number of errors found in version 4.0.
Electronics Assistant (EXE File, 460 kB)

Free Circuit Design/Simulation Tools

Free OrCAD Demo program, which includes demo versions of: OrCAD Capture CIS, PSpice A/D, OrCAD Layout, and SPECCTRA for OrCAD. The limitations of this demo are in the size and complexity of the design.

OrCAD Demo

Freeware program for MAC and Windows to draw and analyze electrical circuits.

Solve Elec

Freeware open-source program for drawing circuits running on Windows. It includes drawing libraries, a SPICE template engine and can export to PCB design programs.

TinyCAD

Open-source circuit-design program for Unix/X11.

XCircuit

Free PCB Design Tools

Freeware open-source printed circuit board layout editor for Windows.
FreePCB


An interactive printed circuit board editor for Unix/X11. It includes a rats nest feature, auto-router, trace optimizer, design rule checking, and can provide RS-274-X (Gerber), NC drill, and centroid data (X-Y data) output for use in the board fabrication and assembly process.
PCB


A free schematic capture and PCB Layout program for Windows.
PCB Artist

Oscilloscope for Windows

Digital Oscilloscope Uses PC Sound Card for Input

Oscilloscope for Windows is a Windows application that converts your PC into a powerful dual-trace oscilloscope.

Oscilloscope uses your PC's sound card as an Analog-to-Digital Converter (ADC) to digitize any input waveform (speech, music, electric signal, etc.) and then presents it on the monitor in real time, allowing the user to control the display in the same way as on a conventional "standalone" scope, for example change gain, timebase or plot Lissajous patterns.

Download Digital Oscilloscope - 91 kB

Schematic Programs

Design Works Lite

One of the best schematic programs we've come across is Design Works Lite and although we have never used it extensively nor fully explored its full capabilities we have seen sufficient to be thoroughly impressed. The "Lite" version can be run unregistered.

Download Design Works Lite.

CAD126

Another little free schematic circuit drawing program recommended to me but I haven't had time to run is CAD126. It is described as an entry level ciruit design program - it's FREE and about 200K in zip file size.

Download CAD126 - 208K

ExpressPCB

This site I came across, ExpressPCB, provides FREE PCB drawing software you can download. You can print it out and do your own thing OR better yet submit the drawing electronically to have a prototype board manufactured.

As Stan from ExpressPCB explained it to me:

"There are two parts to ExpressPCB, free PC board layout software and a low costs PC board manufacturing service. The ExpressPCB CAD software runs with Windows 95, 98 or NT. Designing double-sided boards is a snap with the program's very intuitive user interface. ExpressPCB manufactures very high quality double-sided boards with plated-through holes. Their board manufacturing is both very fast and economical. Most orders are shipped the next business day and for as little as $59.
See http://www.expresspcb.com for all of the details."

Automatic time correction for your PC

SocketWatch

Another personal recommendation. I use it all the time and I paid my US$10.00 registration fee. I have no connection apart from being a very satisfied user.

Absolutely brilliant! SocketWatch is an SNTP client that gets accurate time information over the Internet. If you are connected to the Internet and want your PC clock to be as accurate as possible, SocketWatch is for you. Can be run unregistered but the registered version naturally offers superior features.

I've found over two years my PC receives a daily correction of about 9.369 seconds. Just one indication of the poor time keeping of a PC's clock. At that rate over a month my PC's time would be in error nearly five minutes! Check your time now and see how far off you are.

SocketWatch is not your father’s pocketwatch, but is as indispensable to your connected PC running Windows. In today’s wired world, keeping an accurate clock is more important than ever for the personal computer. To know how accurate is that time critical information you got from the Web, to be sure which version of that file in your Windows Briefcase is the latest, you need your computer, all the computers you use to be synchronized. The best way to do this is to synchronize your PC to the universal time signals available through the Internet.

I use it in conjunction with the Customisable Clock for Windows Task Bar above.

Download SocketWatch latest version Version 3.5b (build 146) Updated 30 Jan. 2002 - 616kB.

Linear Simulator for RF and AC Circuits

NOVA-686 - Shareware $US25.00

Written as a design aid for the RF circuit designer, radio amateur, hobbyist, and student. The primary aim of NOVA-686 was radio frequency design, however this program has proven to be excellent for all analog designs. Not intended to replace spice (the defacto standard) NOVA-686 is strong in areas where Pspice is weak, such as: fast analysis rate, optimization, tweaking, S-parameters, Monte Carlo analysis, and *accurate* RF component models.

Download NOVA-686 - 230K