Solve Elec:
Solve Elec is a free circuit diagram software that provide you preset components which you can use to design electronic circuits. All you have to do is, simply drag the required component to the clutter-free interface, so as to create circuit diagrams with ease. All the components are located to the left side of the window, from where you can choose the desired component in order to create circuit diagrams. It provides you various electronic components such as  inductors, transistors, ammeters, voltmeters, switches, capacitors, supplies, diodes, wires, amplifiers,resistors, and many more. It also provides you various features like zooming in/out, rotating, or erasing, which you can choose accordingly depending on your requirements. The best part of this free circuit diagram software is that, it allows you to write down the formulas by specifying the units, notations, and expressions, and at the same time lets you view the circuit-related equations, along with the solutions generated by the measurement devices. It lets you draw graphs on the graph plotter and allows you to change the position, coordinates, and axis scales. The elements can be easily copied and pasted on the Clipboard or any third-party application. Not only that, it also lets you add images, create reports, and edit text fields. It lets you print the circuit diagram and allows you to export the same in ELN format.
Grab Solve Elec from here!

http://www.ilovefreesoftware.com/28/featured/free-circuit-diagram-software.html