What software is used to draw the circuits in the patent application documents in the electrical field? What software is used to draw boxes?

Protel is the most commonly used circuit diagram, and visio is the most commonly used block diagram. Protel is professional and needs a long study time. If it is only to draw patent application documents in the electrical field, a visio can complete the block diagram and circuit diagram. Visio was founded by a company in Taiwan Province province more than ten years ago, and now it has become a component of Microsoft office. Many of its shortcut keys are the same as Microsoft word, and it is much easier to learn.