On Mon, 09 Jun 2008 11:51:01 -0500, John Fields wrote:

On Mon, 09 Jun 2008 16:01:36 GMT, PCPaul wrote:


So the post at the link is correct?

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Yeah, it's over on alt.binaries.schematics.electronic ---

Or do you want to email it direct, my address works.

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If you can't get it at abse I'll email it to you, let me know. ---

I can see the post at abse, but the pdf comes out as bits of pdf text.
Please could you send it straight to me, saves all the uuencode/yenc type
hassles..

I'll send it straight back if it's your only copy ;-)

Thanks for taking the time to get this far!

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No problem, it was kind of interesting finding a way to save $$$ on that
big cap. :-)

An interesting thought when designing anything new.. just because this
design works perfectly *electronically*, could it be improved along other
axes?

I do recall making a car lights-on alarm buzzer with a delayed off using
a 555, a couple of caps and resistors and a speaker. It didn't look
anything like any of the millions of sample 555 circuits I'd seen, I was
just fiddling about with some breadboard and there it was.

I tended to muck about with analogue stuff back then but didn't get on
with the theory so much - I think computers were just so much more
appealing..

I did like the little tricks I picked up like putting a resistor in
parallel with a linear pot to approximate a log pot response - I needed a
small pot to go in the amplifier we had to design as an apprentice
project and 'stores' only had huge fugly log pots and nice neat linear
ones..

Just make sure the box is waterPROOF and there's no way the circuit can
be touched accidentally when it's energized, since there's no galvanic
isolation from the mains.

Should be OK, it's a commercial IP56 rated switch in a box. Not sure if
you do IPxx ratings on that side of the pond - that translates to:

5x - protected against enough dust getting in to affect operation
x6 - protected against direct jets of water and heavy seas(!)

The next ratings up are 'dust tight' and 'sealed against immersion up to
1m deep' so IP56=a pretty well sealed box.

I will still be careful though, I've had a mains belt before and I
wouldn't wish it on anybody. With 240V you don't go touching stuff with
the back of your hand to see if it's live...