Does anyone knwo what metal and what plating is used for the TO18 version of the 2N2222?
All I have managed to discover is that it is 'metal'.
All I have managed to discover is that it is 'metal'.
My guess is nickel plated steel. Don't have one handy here to take a magnet to.Does anyone knwo what metal and what plating is used for the TO18 version of the 2N2222?
All I have managed to discover is that it is 'metal'.
That's a good point.If not nickel plated steel (I, too, don't have a 2n2222 or magnet on hand to check), it could also be aluminum. I suspect that one is the most likely case, considering they're designed to work for heat dissipation, specifically with aluminum heat sinks, and nickel plated steel (or other ferric materials) don't have the best thermal properties (in that they heat up much more quickly than aluminum does with the same amount of power dissipation).
I have one (several actually), and a magnet, and both the case and the leads are magnetic.Don't have one handy here to take a magnet to.
Huh. I couldn't find this for the life of me. Turns out I was mostly wrong about my guess (though there is some aluminum, just not significant-enough amount to consider my answer remotely correct.)Here's info from Central Semiconductor Corp. Can is mostly iron, external coating is tin.
Yes, exactly that: https://forum.allaboutcircuits.com/...ow-low-flow-low-pressure.170306/#post-1518779Out of curiosity, based on what you said, were you planning to use these transistors as water (or water flow) sensors? Or did I misunderstand your intentions?
Yes, I think I will do that. After it is secured with silicon rubber into the pipe it won't be too easy to replace.A layer of water-proof varnish etc on the case would prolong its life, albeit at the expense of reducing somewhat the sensitivity to water flow.
But the thermal conductivity will be lower and it will be harder to seal into a pipe. The metal version is circular and has a flange which will make fitting it much easier.You could try a PN2222 - epoxy doesn't rust, at least the last time I checked (!).
Oh, yes, a plastic pipe."Pipe"? I hope you're thinking in terms of plastic, because the difference in thermal conductivity between an empty copper pipe and one full of water may not be as great as you think.
How about thermal conductivity and response speed?Guess I don't see the big difference mounting either package in the end of a plastic pipe, but...good luck