If you don't have 3 transistors wired in a way that accomplishes that, you don't violate the patent. (Actually, at least 2 transistors, the other two independent claims cover cases where you replace the third transistor with something else). You don't violate a patent by violating a loose summary of the patent, you have to specifically violate the claims in full.
If it improves on existing practice even if someone would have thought of trying it it is patentable. Think of a steel with a particular alloying element: only 92 to pick from!
