I’ve come across a couple of cool, free tools for circuit design:
TransistorAmp 1.1 – free software for the design of bipolar transistor amplifiers.
On the AMRAD mailling list, Phil, M1GWZ writes:
Okay, all a transistor circuit that I’m developing needed was a 5x voltage gain stage. Yes, I could have thrown in a single op amp with split power rails and all that DIL8 real estate, but a single transistor stage would suffice. Trouble is, I’m an EE by inclination, not training, and all those calculations – working out those capacitor reactance values – well, I don’t do them often enough for them to be easy. And I want voltage gain, not current. And then I found…
Nice piece of software, installs easily and it works. Okay, not cutting-edge state-of-art stuff for anyone here, but it did the job for me quickly and easily. Oh, and when I built the circuit for real – voltage gain of 5x !
Altium CircuitMaker. CircuitMaker is targeted at hobbyists, people like you and me. Maxfield Parrish of EETimes says, “one key aspect of CircuitMaker is its intuitive and easy-to-use interface — all of the important “stuff” is presented in an easily accessible manner in a ribbon at the top of the display. Another major consideration is that Altium has decided to make CircuitMaker all about “Community,” so users can easily share ideas and designs, comment on designs and offer suggestions for improvement, and generally help each other along the way.”
Top Free DIY Tools Every EE Needs. This article contains links to a variety of tools, including calculators, circuit simulators, logic simulators, and PCB design tools.
Elwood Downey, WB0OEW says
I use easyeda.com. It performs schematic capture, spice simulation and PCB board layout. It’s all web-based so nothing to install, all free and excellent support. I sound like I own it but really I’m just a satisfied user.
Dan KB6NU says
Here’s a follow-on article: 10 Free Math Analysis & Design Tools for Engineers.