6070 seem a nice unit, linear, 500uv ripple, it seem also fanless. I not know how a fully linear supply can dissipate 150w of power without a fan. Maybe have an smps pre-regularor before the linear stage?
No. The way how they do it (in most of this kind of cheap PSUs) is that the transformer has many secondary windings and they switch between them with relays. In my PSU they switch every 4 volts. This can reduce the power dissipation need to around to 5A*5-7V that can be passively cooled already.
This has also its disadvantage though, especially if it's used in a way that relays have to be switched a lot as it can wear them out. For example constant current mode can mean a lot of switching.
A few points that was important for me when selecting PSU:
- Output switch, so that adjustment is possible without unplugging the powered electronics/no immediate power after switch on
- Constant current mode but sometimes it's good to have also overcurrent switch off mode (some SMPS have only this)
- Low noise (switching mode PSU vendors prefer to specify only RMS but Peak-to-Peak is very good to know)
- Quick reaction to load change (and load not much impacting output voltage)
I ended up not one type but multiple types. The SMPS that I have has lots of power (10A) and many features in a small form factor but it required modding to get the noise even below 5mV RMS/100mV Pk-Pk. It has also slow reaction time for load change. The linear PSU that I have does not have a very good interface (but at least it has output switch) so that fine/course setting may require extra iterations and has the relay switching issue (that can impact durability) but it has very low noise that is actually hard to measure.
I've never had a PSU with a push button only interface and my concern with that when slow increase of voltage or current is used to check the impact it's probably slow to do with such interface.
My most preferred interface (have not seen in this kind of cheap PSUs) that fine control is without limits (so that there is no endpoint with fine control where you cannot go any further). With rotary encoder it would be easy to do but still not used.