Why SHUNT DC Regulators are not popular?

[001]

Hi!

I see that all of commercial linear power supplies use power transistor in series with load

Why parellel wiring aka shunt regulator  is not so popular?
I see many benefits like low output impedance, shorting stability etc

Any opinions?

[brabus]

I would say the main issue is the inverted logic in comparison with a series regulator: in a parallel regulation scheme, you need to burn all the power you don't need, both in the regulation element and in the series resistor. On full power, you reach the same efficiency as the equivalent series regulator, but in all other cases you are wasting more heat.

Given the fact that power supplies are seldom used continuously at full power, you would end up with a nice stove for winter times. Heat causes then quicker aging of the system.

Output impedance in a power supply is basically never considered by the traditional designer (plenty of filtering on the DUT); in case of need he/she will buy a 4-quadrant supply.
Short circuit protection as well: old problem, solved in many ways since the early days of electronics. Basically every power supply is short circuit tolerant nowadays.

[glarsson]

Be clearer. Parallel pass elements (using several transistors to increase current capability) is not the same as connecting a regulator in parallel with the load. The question seems to be about the second case, usually called a shunt regulator.

[001]

usually called a shunt regulator.

Yea
I mean shunt regulator sorry for my english

[Zero999]

Shunt regulators are regularly used, but only for very low current power supplies, such as voltage references. Look at many power supply schematics and you'll commonly see the voltage reference is generated by a zener diode or shunt voltage regulator IC and resistor. They are not used for high power regulators because the power draw is the same, irrespective of the load, as mentioned above.