Is not necessary add useless or power consuming components like mosfets etc to realize this ultra simple purpose. This circuit consume 16 ma. Other uselessly circuits more. As my grandfather said, only an idiot can want to spend more to have the same thing.
Any attempting to justify more complex schematics, like circuits made only for demonstration (wrong demonstration of course) are no-sensing under a technical point of view and definitively to do not follow as examples.
How wise my grandfather was!
