Don't forget...the PCB if used need to be spotlessly clean, free from solder flux and residual.
I have used relay but mounted on PCB, need to be washed with cleaning chemical 3-4 time until it look shiny. Then you need to apply conformal coating on top to avoid dust and contamination from surrounding enivornment. This give leakage current less than 1pA.
Mounting the relay in the air is even better but unsuitable for general needs. PTFE PCB is too expensive and specilised.
Good luck
W> >
Hello Jim,
It always left me quite impressed that TV sets in jazz and blues pubs with tobacco fumes wafting around would keep working.
In that test set the creepage path wasn't the only problem. One of the relays had become intermittent upon contact closure. Did the usual cloth paper ritual and when I pulled it out the first time, yuck.
The heaviest smoke experience was at a Korean company. They had smoking banned from the cubicle and lab areas but because everyone seemed to smoke they reserved a large room for that. Since consultants get called in when there is a hardcore problem that's where the schematics were dragged to, because the guys were nervous and needed the nicotine dose. Oh man. I don't mind smoke but that was a bit much.
Regards, Joerg
One upon a time, ther were mercury=-wetted redd relays that were perfect for uses like this. But some damn politico decided that he need to pass yet another law...
I would think that the problem would still occur, as the smoke would condense on the glass, thereby providing a shunting path...
Hello Robert,
Not really. You can buy Reeds that are almost an inch long and they can be mounted in a shrink tube fashion, encapsulating the whole thing. For really harsh situations the whole thing can be potted up. This can also be done with some relays but their limited lifetime can become an issue.
Regards, Joerg
Be glad you can still TALK about this. I'm worried about the next decade or so, we're getting into "thought police" territory these days (don't even grumble under your breath while waiting for the useless security theatre at airport check-in; you don't even have to say anything, they can arrest you for a tone of voice they didn't like, even if it was all in their imagination)
so,
under
they
...and a clever person could carry a gun that is 100 percent non-metallic (would be good for only one shot, but...) and/or explosives that are not detectible by any of their detectors or proposed detectors. Add in binary explosives, and exotic CBW stuff and...
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