On 25.04.18 10:20, Jon Elson wrote: > On 04/25/2018 04:48 AM, Erik Christiansen wrote: > > As mentioned upthread, a linear regulator wastes power. But cheap > > switchmode power supplies tend to radiate RF, and wipe out radio > > reception in my remote rural location.
> It is possible to place switchmode supplies in shielded enclosures to reduce > radiated EMI as much as you want to. Yup, that's granted, and I considered it and decent filtering at input and output, but significant numbers of distributed "linear current sinks, and one central very well screened & filtered SMPS" make for a simpler design, and is risk free. (I have chased EMI reduction at a testhouse, trying to get a plastic-cased Japanese telecommunications product through certification, and it was a hell of a hassle. I'm not looking for a similar experience while building one house and renovating a second, with a 500 km return trip in between.) > The power savings can be enormous. If your DC bus voltage is VERY > stable, then you can use linear regulation with minimal loss. Indeed. As previously stated: "For that reason, rather than make the aforementioned LED lamp dimmers switchmode, they will be linear current sinks, and one central very well screened & filtered SMPS will drop the 48v battery bank to 21 or 22v." > But, if the lights have to work when the battery is being charged > through being discharged, you can't be that efficient. That's what the one central very well screened & filtered SMPS is for. I can buy that, add EMI filtering if needed, put it in one extra enclosure if needed, and entirely avoid those issues in the multiple distributed linear current sinks. (Skipping any potential need for ugly metal enclosures.) Designing is fun, redesigning less so. This needs to just work, so I can move on. Erik ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
