I was wondering if there was a simple program out there that would help me design and toubleshoot schematics I draw? For example, I have a schematic for a power supply that takes a 6.5k "core and coil" transformer and ups the voltage to 15k to supply a Van de Graaff generator. Now, the problem is I want to test a few things about it, including the 1 megohm resistor on the ground, before I actually build this thing. So, is there a program out there that will allow me to test stuff like this out before I build it and toubleshoot it for real? I'm sure there is I have just missed it, or not been searching google properly. Thanks!