In summary, there are a few free circuit testing programs available, such as SPICE-like freeware from chipmakers like Linear Technologies and TI, and the ICAPS Spice modelling software from INTUSOFT. These programs offer features such as graphical displays of DC initial condition voltages, parametric sweeps, and a wide range of component libraries including diode models. Some programs have limits on the number of components or nodes in a circuit, so it is important to check before use.
Does anyone here know of a good circuit testing program that is free that includes diodes? I need to find certain voltages on specific points on a circuit, and I can't find anything good out there that can help.