06-05-2021, 04:06 PM
(06-03-2021, 06:20 PM)kuseaadu Wrote: Hi. I have a RPI4 and Boss2. Thinking about powering options. For sure its going to be 2 separate supplys. For DAC I have a linear supply in mind. For Pi im undecided between linear and switching . I also have a 7" screen that draws a bit under 0.5A. Might add a HDD later so a bit of headroom for that would be great. So the second supply should be I guess ~4A+. At 4A I'm wasting enegry and generating quite some heat with a linear supply. Should I expect any increase in performance (sound quality) from 2x linear supply vs linear for dac and 5V switching (for example 5V Meanwell switching unit) for Pi, screen etc?
Hi, is the linear PS to be an DIY project or an after market unit?
Between if is an DIY PS unit, then I would go with a single either fixed or adjustable regulated 4~5A linear PS with a toroidal transformer and larger output filter capacitors, and a simple over-voltage crowbar circuit for safety(optional), and there's still enough current for further hardware upgrades and experimentation.
Another more efficient option for always-on devices is to use a very high quality switching PSU followed by an linear regulator to post-regulate and smooth the output, more info in this regard here: Minimizing Switching Regulator Residue in Linear Regulator Outputs, also explained HERE
In regards to the external HDD, if you will use an externally powered device such an Western Digital My Book or similar, you don't have to worry about power consumption, however if you plan to put a USB powered 2.5" HDD, bear aware that they need a small inrush startup current unlike SSD's, so if the power supply is too small this may cause Rpi stability issues.
Good luck with your project.
Regards
