green force style dive light

archer6817j

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Aug 9, 2010
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Mountain View, CA
even without venting, im sure the heating that can happen during charging could be enough to cause concern in a sealed environment.

I hope to be doing some empirical tests on this in the next couple of weeks so I'll keep you posted. I got a +/- pressure gage that reads to 1/4 psi so I'll build an enclosure (with a relief valve) and see what kind of pressures develop. I'm just using a standard charger so I don't think the charge current is very high...I think 1.5 amp max for a single cell or something like that.

Does the piezo switch require a source current or voltage? I've been thinking about using one of these. So far I've been using a MOSFET/reed setup what works nicely.
 
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b-bassett

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Nov 22, 2008
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Does the piezo switch require a source current or voltage?
the piezo i used just fits into the circuit in place of a regular momentary switch, no other cables required.

it actually gives a very brief electrical pulse to the circuit, so you cant hold it down like a mechanical momentary switch. (hence the need for a latch circuit)

any other questions feel free to ask, there's a few others on here who have been looking into and using piezo's and latch's

jon

p.s.

good luck with the testing, it should give sum insight into possible problems with completely sealed designs
 
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b-bassett

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cheers Lucca

id found ~(and lost) that pdf befor but could never find a supplier.

iv jsut done a search, and it seams that RS now have them as new stock

think ill have to get one for trials
 

SmokedCPU

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Jan 9, 2010
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Quebec, Canada
Hi,

First congratulation for the nice work. Being an electronic guy, not a mechanics, lathe work always mesmerize me.

Piezo switch was atracting me at the begenning, but it was kindna hard to get a supplyer so i went to momentary piezo switch way, with polulu toggle circuit. Other user had trouble with circuit not closing, but ive used my 3 circuit, without any complain even if i was using a normal voltage out of spec, and the two other on their ranges.

One was still working even after a salt water flood at 6ft, dived even tought, 43 minute, was still working. Replaced it for safety purpose.
maybe you can go to their website and check out their mosfet, some are working with verry low voltage. here is the link http://www.pololu.com/catalog/product/750

cheers
 
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