/diy/ - Do It Yourself

>>2048170
>I'm an CE and I don't have much experience with analogy stuff like Transformers etc
Bob Pease has a story just for you
there are common transformers for common applications on aliexpress, including the ubiquitous 5V 2W USB "charger" with shite load regulation, and there are companies that will custom-wind them to your spec in lots as small as 5 for pretty reasonable prices. creating the spec is more difficult, esp for flyback transformers, as there's a lot to specify about the core
off-line SMPS are a fun challenge, no doubt, but they are no joke. you are going to need some power electronics background and great workmanship in order to reduce the likelihood of your circuit blowing up in your face below 1, even if you take one of the Power Integrations cookbook designs or wizard designs and follow instructions and BOM precisely. at the very least grab the canonical book on SMPS (Pressman) and try to understand what you're signing up for on this ride
important: shield your face and eyes against small explosions and flying objects, and use an isolation transformer. a plexiglas cover for the circuit would be wise too
potted, isolated power supply modules such as CUI's VSK series or many chink clones solder right on to your board, in sizes from 1W to 25W

>>2048142
LM311 should be fast enough for the lower part of your range and has an uncommitted transistor output, though an open emitter output has its own problems when it comes to speed and stability
at the upper end of your target range, LMH6600 series are decent, cheap, fast CMOS RRIO major-brand op amps that don't consume ridiculous amounts of power, but read the datasheet before trying to apply them as comparators. there are chinky opamps like GS8091 that are 1/5 the price with about the same level of performance and treachery