Back on this supply project, since it's been lying dormant for quite some time now, my original plan was to have two DPS modules side by side, but that got me thinking whether it'd be a good idea for the second module to be a linear supply which would supposedly give me a less noisy output. I got the idea after watching a video of Dave Jones where he shows the noise output of those switching DC-DC supplies I'm using here....it's probably of no concern to me, since I don't work with things that require that sort of precision, but I'm still considering it.
I found this thing on Ali, but I wonder if it can do constant current mode or it's just one of those "trip-point" current settings like I had at my old shop. It did the job, but it'd still be nice to have something that automatically brings down the voltage to maintain constant current. That one just beeped and cut the output entirely...
Yes, I watched that one too, but wonder if it applies to the ones I have...I don't have a scope myself, so I don't know how bad the noise on these can get and whether I should even be concerned in the first place....
The transformer shown in the schematic for that linear supply on Ali poses a problem, since I don't have that many taps to play with. I only got one center-tapped output, so I don't think it'd work with just that. I'd be able to create the split-supply at the top (L2), but I would have nothing to power the "hot" side at the bottom.....
IMO, taken in consideration the specs (and price!) the ripple results fall within the advertised 100mV typical, reaching 150mV @ maximum current output (6A), which should be considered the worst case scenario.
Ultimately it will come down to what you will be using it.
Although, as a general rule, variable linear power supplies have less ripple than switched power supplies, this however heavily depends on the load.
Furthermore, variable linear power supplies are prone to overshot and undershot the output voltage.
As an example, ripple and overshot / undershot wise:
if the load being powered changes and fluctuate heavily and fast over time then a variable linear power supply will, most likely, perform worst than a switched power supply.
I wonder if THIS technique Dave talks about can be used here as well...
Short answer: Yes
Long answer:
But has said before you´ll have to draw a line where you want to stop the increase in complexity and cost vs. the ripple output noise.
IMO in a typical "all terrain" workbench power supply, meant to drive high power loads, tens of mV ripple output noise are well neglected.
But again it all comes down to type of use you'll expect to give it...!
If, on other hand, you will mainly use it to drive low power, sensitive, circuits, lets say for example 1.8V audio or frequency related circuits, then tens of mV ripple on the voltage rail will be unacceptable.
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