Spencerleehorton said:
its seems we have a difference of opinion!!!?
Abbey says its inadequate for this purpose and squarewave says it works well?
could someone explain why a SMPS over a linear is quieter?
My main concern was with the fact that this type of smps is designed to power LED's, which means the primary regulated parameter is output
current, because LED's want controlled current. However, the regulation performance is definitely not a s strict as it is for phantom voltage. An LED string does not require 1% accuracy, and noise is a non-concern (within limits).
Typically, I don't know how accurate is the output voltage when such a unit used for phantom powering (i.e. way below it's current-regulated zone), and most of all I don't know how noisy it is in this case, because it is a non specified parameter.
Using a bleeder resistor would only ensure it is not in choke mode, but would not guarantee any kind of voltage /noise performance.
That's the reason why I would not recommend this type of smps for phantom. I'm not saying it can't work, but it's kind of a lottery there.
It would take a very bad designer to build an unusably noisy linear phantom psu, but I've seen it happen; it's not proof that the concept doesn't work, just that a viable concept needs a viable implementation.
There are many smps that are designed for voltage mode, and their voltage regulation and noise performance are well documented. It is a much safer bet. Indeed, adding complementary filtering in order to get rid of HF noise components is wise. One should make sure HF noise do not enter the system. There is usually additional filtering on phantom distribution, so conducted emissions are not a serious concern, but radiated emissions should be avoided, by containing them outside the powered unit.