With reference to Olin's answer to Connecting Voltage Regulators 7812 in Parallel for High Current, and likewise the examples from the Fairchild, TI and ST datasheets, a PNP transistor is used (i.e. TIP42, BD536, 2N6133, BD536, respectively) to provide the higher current, when using an LM7812.
Looking at the Fairchild example:
I would assume that (in a dual rail supply), for the negative rail, using an LM7912, a complementary NPN transistor equivalent would be required (i.e. TIP41, BD535, 2N6130), instead of the PNP for the 7812. Is that correct?
Likewise, for the short circuit protection schematic using the LM7812, an additional PNP transistor is used (i.e. 2N6124 (for the TI and ST datasheet examples), and TIP42 (for the Fairchild example)). Taking the Fairchild example again:
In addition, I presume that the orientation of the transistors is the same - that is to say, the Collectors and the Emitters of the NPN equivalents remain connected the same - and they are not reversed? To be exact, the Collectors of the two NPN transistors go to the input and output, respectively, of the LM7812?
Please note I'm not looking for component recommendation, but rather I would like to confirm that I have got the BJT polarity configurations (PNP versus NPN) correct. I have merely included the component identifiers for completion.