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| Very wide range isolated DC-DC converter |
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| forrestc:
--- Quote from: T3sl4co1l on January 19, 2019, 04:55:43 am ---Holy hell, how many of these things are going to be deployed? Ten thousand on a site? You'd think they could muster some cleaner power if there's that substantial of an installation going in! --- End quote --- This is much more of a concern for smaller sites... At a site where the entire power consumption at the site can be as low as 20W, an additional watt (or two) can be a big thing since you've just increased your power needs by 5% or 10%. At a solar site in northern climates with 1 hour of insolation (not all that uncommon), a single watt 24x7 increases the solar panel needs by 24W. Plus most off-grid sites like this like to engineer for 2 weeks of batteries in the event of no sun or a solar system failure. So that single watt increases your battery needs by 336 watt hours. This doesn't sound like a lot but in these small systems it can add a couple hundred dollars to the cost of the site, and when there are dozens or hundreds of sites where these are deployed it can add significant cost. The 2-3 battery rails comes from the fact is that it is common for these sites to end up with 2-3 separate systems: A separate +24V system and a -48V system in combination is really common for historical reasons (gear that came out of telecommunications often runs at -48VDC, gear that came from data communications/industry/telemetry/scada often runs at +24V (or +48V). Some people will build one battery system, and use DC-DC converters to get the other rails, but others tend to find that building two separate systems works better for them. One of our distinguishing factors is the lower power consumption of our solution. Many of my competitors have chosen to go down the 'it's only a few watts' path, and as a result, I'm picking up a lot of sales from those people where every watt really does matter. I do a lot of work to be able to put "under 1 watt average power consumption" on the datasheet, because that makes it easier for the customer to feel like they can add our solution to an already tight power budget. |
| mk_:
--- Quote from: coppercone2 on January 19, 2019, 02:20:40 am ---200v is no problem for lt https://www.analog.com/media/en/technical-documentation/data-sheets/7860f.pdf --- End quote --- abs. max. Ratings say 60V. Tose 200V are only possible with some tricky GND-shifting which is nothing I would use for a (isolated) DCDC-Converter. |
| coppercone2:
there is also this thing https://www.analog.com/media/en/technical-documentation/data-sheets/436612fe.pdf |
| jbb:
I hate to be a party pooper, but this looks like an ill-defined and challenging space. If people want minimum power consumption (ie max efficiency) and (presumably) moderate cost then you should simply make a small number of simpler products to fit the space, rather than trying to build One Converter to Rule Them All. If you want to persist with the high efficiency + super wide range approach, then the best result might be found using a non-traditional converter. For example: - polarity can be inverted from -48V to + 48V using a switched capacitor converter at fixed duty cycle and frequency. Sure the output won’t be regulated, but the subsequent buck can fix that. - multilevel converters can offer a more reasonable way to work with high conversion ratios and still have reasonable duty cycles (eg a Flying Capacitor converter) |
| coppercone2:
this spec has military written all over it IMO |
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