darktable is an open source photography workflow application and raw developer. A virtual lighttable and darkroom for photographers. It manages your digital negatives in a database, lets you view them through a zoomable lighttable and enables you to develop raw images and enhance them.
Have a look at our current features and how to install it on your system. And if you're new to darktable, the FAQ will answer many of your questions.
If you are a student, ask your electrical engineering librarian. Many libraries have a "Course Reserves" digital scan available only to enrolled students.
Since you are using a PDF, you have a computer. Try to simulate a simple DC motor model in LTspice or MATLAB/Simulink while following Hubert's equations. This bridges the gap between the 2D diagram and real physics. Electrical Machines By Charles I Hubert Pdf
If you cannot find a legitimate PDF, or you want a high-quality digital copy, consider these routes:
Transformers
Direct‑current (DC) machines
Synchronous machines
Induction machines
Machine testing and performance
Design and construction notes
While it is technically possible to find scanned copies from the 1990s or early 2000s (usually of the 2nd Edition), these come with significant drawbacks: