Linear Voltage Regulator 2

Your last sentance about linear regulators is not true. Linear regulators are infact used to high power powersupply applications as well. Although a lot of power is dissipated in them, sometimes linears are preferred over SMPS for multiple reasons.

Power supplies as in bench top? Those are not the type of supplies you put into circuits. Linear supplies such as in this circuit is for low power applications, like constant voltage references, which are temperature resilient. Unlike zeners for example. Also bench top supplies use transformers for isolation prior to multiple charge pumps for negative references, while here one can see ground isn't isolated. Also bench top power supplies induce phase factor due to passives for filtering rather than active as in this circuit. Other use of linear regulators is for RF equipment, usually expensive hardware so wasted power is the least of your worries. Besides, bench top supplies due to the use of charge pumps for references, they are no longer considered linear. Try running an FFT on the line coming from a bench top supply. You will see many harmonics.

Oh I forgot, efficiency in voltage Regulators is very poor. So power consumption is normally the primary reason we prefer them for low power solutions. Thermal runaway would impact the rest of the circuits onboard.

@xD that's mostly a load of drivel. You have just put together a bunch of random facts together in your comment. Why did you even bring PFC here? Ok, so let me tell you one thing: Linear bench PSUs are available, irrespective of what you think. Yes, the power dissipation is high, but they still make them due to several reasons.

So your science is basically running troll comments. I get it.