A note on portability of these "permanent" LTspice Components:
Many comments are made about the lack of portability of creating these permanent parts in LTspice. The approach preferred by most is to include the symbols and SPICE models directly in the folder of the schematic you are testing. PLEASE NOTE that using this method to create permanent LTspice models does not prevent this portability! Create your permanent part, or add the parts from the list below. When you share this schematic with others, or use it on a computer that does not have this component, just copy the 'asy' file and its associated SPICE reference to the 'asc' file you are providing to the foreign computer.
In this way, you can have the best of both worlds: You can build up a permanent library of useful parts, immediately accessible when you create a circuit AND you have portability!
