Re: VFDs, Noise, and RS-485

Joerg wrote: 
Hello Terry,

we had a showering arc generator for EMC susceptibility, and every time we turned it on the R&D/production door swipe-card died, so all foot traffic had to go thru the power lab. The mfg eventually fixed it. The first time the SAG was powered up, the photocopier died too, so we bunged a line filter in front of it and that kept it alive. Phone conversations were tricky with the SAG on too :)


When I tested one of my designs for defibrillator safety the PBX system quit and some computers froze up. I got dirty looks despite the fact that I had placed a huge wallpaper on an easel at the entrance asking people to back up a lot that morning. 

to quote JT, BWAHAHAHAHAHA


BAV99 to the rescue....


Or BAT54 duals if you need to cap before the substrate diodes wade too deep into the muck.

ayup. You've done this before.... I once managed to design a circuit that occassionally triggered the parasitic supply SCR in a lattice CPLD. The numbers would burn off the chip, and a little dome would swell up in the centre of the PLCC. oops.

If you're interested, I posted the PDF showing how to make one to abse.


Cool. I am surprised they recommend plywood for the applicator side. In California the fire marshall would have a beef with that. Maybe it isn't as hot and dry in Australia as it is here. The transformer could probably be scrapped out of one of those bug zappers. Is "AS" Australian Standard?

I used a neon xfmr fed from a step-down xfmr to get the right voltage (it was free). When I say "I" I mean my slave ^H^H^H^H^H^H technician. He did a much nicer job than I would. I think we made the frame from formica, but your right, plywood might not be such a good idea. Mine is in a big Al case, so it can catch fire inside if it wants to :)

Yes, AS/NZS. We often pinch the standard numbers from europe/usa....


Regards, Joerg 

Cheers
Terry
.