On Tuesday 15 December 2015 10:33:55 John Kasunich wrote: > On Mon, Dec 14, 2015, at 10:51 PM, Gene Heskett wrote: > > On Monday 14 December 2015 19:11:49 Jerry Scharf wrote: > > > Hi, > > > > > > Just did a super quick google search and came up with a fairchild > > > optocoupler hcpl2530 that will do 1Mbps. ~1.80 USD quantity 1. > > > Isolation to 480v and good common mode rejection. There are a > > > number of devices in similar and better speeds. > > > > I was wondering if faster stuff was filtering down into the > > afordable category in the last decade, But only 480 volt isolation? > > that would have to be mesa isolated on the same substrate, edge > > emitting diodes facing edge sensitive transistors. I think it > > depends on the environment if thats enough isolation. With noise > > from higher speed/volatge stepper drivers nearby, I'd be a tad > > nervous. > > "Only" 480V? > > Jerry wasn't saying "these devices fail at 481V". They are UL > approved for use as isolation between 480V power systems and > low-voltage control. The actual isolation rating is far higher than > that. The hipot test spec is 3750V RMS for 1 minute. > Thats much closer to what I was hopeing for John, thanks. Most it seems are rate in the 4 to 5 thousand range. So I do not expect any surprises.
> Optos are getting pretty good these days. At work I use the Renesas > PS9924, an extra-wide body one that can meet safety regs at 690V AC, > even at high altitudes where thinner air requires larger clearances. > Hipot rating is 7500V RMS! Sub-100nS prop delays, easily handle 5MHz > data. Cost is still under $10 each, $5 in quantity (a bargain if you > need such performance). Datasheet: > http://documentation.renesas.com/doc/YOUSYS/document/r08ds0059ej0100_p >s_family.pdf These things are, I assume, SSR's at heart, meaning they are intended for AC service only if ever expected to be turned off? The ones I have coming are probably older stuff and the SSR portion would be slower too. But that, in this circuit, shouldn't be a concern. They'll be a few days arriving, so I'll have plenty of time to conjure up a safety bleeder. And figure out how to interlock it so it cannot be re-enabled until the bleeder has done its thing and self disconnected. I have some 3pdt ice cubes and one of those, self latching until the cap is down, is likely to find a new home. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Some mill pix are at: Genes Web page <http://geneslinuxbox.net:6309/gene/GO704-pix> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
