Circuit Diagram is a free, open source application which enables you to make electronic circuit diagrams and export them as images.
This software is available for windows OS and not require many resources , but in same time it don’t has many features .

eSketch PRO is a schematic capture and simulation application software specifically designed for the ultra fast rendition and simulation of frequency-shaping analog circuits such as preamplifiers, amplifiers, active filters, passive filters, crossovers, equalizers and tone controls. eSketch is a specialized program for circuits containing capacitors, inductors, resistors and op amps.

SwitcherPro software is a very useful free software that allows users to design power supplies with Texas Instruments power controllers from the TPS40K, TPS50K (SWIFT), and TPS60K (LoPwrDC) families.
Using SwitcherPro power supplies design software you can design and optimize your power supply circuit using few steps .
SwitcherPro also provides common evaluation module (EVM) designs that can be used for reference or starting points for custom designs.
To create a new design using this power supplies design software is very simple and you have two possibilities :