What does "group regulated" mean? What is better and why?

[SM1LE]

Hi, everyone.

I am going to be making a separate post for recommendations on a power supply, but in poking around I see comments about this or that power supply not being very good or recommended because it is a "group regulated" power supply.

Could Meghan54, lehtv, jonnyGURU, or any of the other more knowledgeable people around here elaborate a bit about exactly what "group regulated" means? What is better and why?

Thank you very much in advance for your feedback and sharing your knowledge and insight.

-SM1LE

 

[Zap]

Generally speaking independently regulated PSUs are "better" but more expensive. With group regulation, your voltages/ripple may go out of whack if you have a bad crossload on it (such as trying to run dual PSUs with the second PSU only supplying graphics cards). Also, independently regulated PSUs will have pretty much the entire wattage available on the +12v, which is the more important voltage for current hardware. With independently regulated PSUs, the entire PSU is +12v (except for 5VSB?) and all the minor rails run off +12v.

 

[Mark R]

A regulated power supply is one where the output is monitored and the power supply automatically compensates for things such as voltage drop (due to load) or a drop in mains input voltage, etc.

On an independently regulated power supply, every output voltage is measured and has its own controller circuit, ensuring that each output is correct.

On a group regulated power supply, one regulator supplies two or more outputs, via a transformer with multiple multipliers. E.g. most ATX power supplies regulate +12V and +5V as a group. One regulator is connected to a transformer which has 2 outputs (where one output is 2.25x the other). The average voltage is sensed and compensated. So, if you suddenly put a big load on +12V causing it to drop, the compensation will result in partial correction of the 12V drop, and a slight overvoltage of the 5V.

With this type of group regulated PSU, if the load pattern is very different to what the designer expected, the 12V and 5V voltages can go out of specification (because it is only the average that is regulated).

 

[Zap]

:thumbsup: