pspice

PSPICE

 9.1 Student
Free   
76

Simulate your circuits to test their reliability and performance.

logisim

Logisim

 2.7.1
Free (Open Source)   
6

A system to learn and simulate digital logic circuits.

tinycad

TinyCAD

 2.80.03.514
Free (Open Source)   
1

The tool you need to edit drawings of electronic circuits.