Circuit Design - Simulation

sPlan 7.0

With sPlan you will design your schematic circuit diagrams clean and easy on your PC. Many powerful functions like the the extensive component library, the usage of free definable background form sheets, automatic component numbering, component searching, component lists, etc. will help you. Even beginners will create perfectly designed schematic diagrams within minutes.

Fritzing

Fritzing is an open-source hardware initiative that makes electronics accessible as a creative material for anyone. We offer a software tool, a community website and services in the spirit of Processing and Arduino, fostering a creative ecosystem that allows users to document their prototypes, share them with others, teach electronics in a classroom, and layout and manufacture professional pcbs.

AACircuit

Andy's ASCII Circuit design

VirtualBreadboard

Virtual Breadboard for Arduino is a learning 'App' version of VBB designed to help you take the first steps in the exciting world of physical computing with the Arduino microcontroller and ‘Breadboard’ based electronic circuit models.

PSU Designer II

PSU Designer II is designed to help you with the design of simple linear (unregulated) mains power supplies, as often found in tube amplifiers.