Hi Greg.

11-Mar-04 09:04:00, Greg Mayman wrote to Jasen Betts



 JB>> I measured 400K between the tracks on the stripboard. dunno if
 JB>> the 30C heat and 100% humidity had anything to do with that.

 GM> 30C isn't heat. That's just a nice fine day.

 GM> The very high humidity might have had some bearing on it. I don't
 GM> recommend any humidity over about 60% except for washing or
 GM> cooking 

I can't reach out the windows and turn off the rain...

 JB>> so I stripped the components off the board and built the whole
 JB>> thing free-standing between two wires...  seems to work now.

 GM> And now it's working you can pot it in resin or perspex to keep it
 GM> in shape and protect it from moisture.

 GM> I wonder... was it conduction in the body of the board or only on
 GM> the surface? And if it was on the surface, why wasn't it over the
 GM> surface of the components when you did the free-standing version?
 GM> Better ventilation perhaps?

two tracks on a stripboard are closer for a longer distance than the
terminals on a transistor, also phenolic board seems more porous than the
plastic encapsulaation used on transisors,

 GM> I'm also wondering what sort of board was it - fibreglass,
 GM> phenolic resin, or what?

phenolic stripboard (like veroboard but this has a Dick-Smith brand)

 GM> And did you try wiping it dry before
 GM> taking the readings?

It was raining at the time, it's hard to dry anything in 100% humidity.
and what use is a device that fails everytime the humidity goes up?

I haven't potted it yet, but have installed it in a case.

 -=> Bye <=-

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