Under Water

[Tec]

I built an underwater enclosure.

No headphones, The Speaker was Piezo loud-speaker connected to an aluminum plate.
On-Off switch is a Piezo button

Results:
Couldn't hear the audio under-water, the enclosure leaked and shorted out the battery.

But it felt comfortable to use, and the coil is fine..

Back to the drawing board: will change to underwater headphones, and make some improvements.

[Davor]

I thought of the similar solution, and came up with idea to pour paraffin into the enclosure. Professional equipment is often poured with oil, but it requires good seal, and access to proper oil, but paraffin is something you can buy just about everywhere, and it won't leak under any normal circumstances. Batteries can also be sealed in parafine, provided they do not need gas vent to operate properly, and if you need access anything, just blow some hot air. Paraffin melts at under 80°C so you can't ruin anything at proper temperature setting, and there you have it.
I also thought about replacing potentiometers with up/down counter and a primitive DAC used as a potentiometer. Operating of switch on/off and potentiometer up/down can be achieved by reed contacts and a magnet that you move on the outside.
I guess if everything is sealed properly, and battery charging is done wirelessly, such a device could go much deeper than you can, and at a silly price of added components.

[DOOLEY]

or use regulated air pressure..........

either fixed pressure, above the depth you require to dive to,
or regulated, similar to scuba regulator, pressure out is always slightly
greater than surrounding pressure.

if casing does leak, bubbles will be seen,
as long as bubbles can be seen,
then all is fine............

when the bubbles stop however,
then you've got problems........
lol.

[ionut_mtb]

I thought of the similar solution, and came up with idea to pour paraffin into the enclosure. Professional equipment is often poured with oil, but it requires good seal, and access to proper oil, but paraffin is something you can buy just about everywhere, and it won't leak under any normal circumstances. Batteries can also be sealed in parafine, provided they do not need gas vent to operate properly, and if you need access anything, just blow some hot air. Paraffin melts at under 80°C so you can't ruin anything at proper temperature setting, and there you have it.
I also thought about replacing potentiometers with up/down counter and a primitive DAC used as a potentiometer. Operating of switch on/off and potentiometer up/down can be achieved by reed contacts and a magnet that you move on the outside.
I guess if everything is sealed properly, and battery charging is done wirelessly, such a device could go much deeper than you can, and at a silly price of added components.

Davor did you tried parafine on pcb's?

[Davor]

Not yet. I'm a bit busy now.

[Davor]

Is there a battery guru around?
I need to know which chemistries are not venting any gasses in exploitation, so that they may be completely sealed?
The idea is to dunk a battery in an enclosure that will be poured with paraffin. So if there are gasses produced, I'll have a problem.
Any takers?

[waltr]

Is there a battery guru around?
I need to know which chemistries are not venting any gasses in exploitation, so that they may be completely sealed?
The idea is to dunk a battery in an enclosure that will be poured with paraffin. So if there are gasses produced, I'll have a problem.
Any takers?

SLA if not Over changed or discharged.
LiIon, NiMH, NiCad are all sealed.

LiPo are Sealed and do not vent BUT can expand (puff) their aluminum 'bag'.

[Davor]

So basically any of the nowadays batteries are OK for dunking into paraffin. Nice.

I also wondered about hardening the paraffin. Standard would be stearin, but... there is a chance it is conductive, and also there is a chance it reacts with component surfaces. I don't have it at hand, so I cant test it. Candle makers recommend using vybar instead, and that's something I really have no clues about.

So most probably it will be a pure paraffin with no additives ... to be on a safe side.

[waltr]

I would use heat shrink with silicon sealer to seal the shrink tube end and wires.
Silicon sealer works very well. If using around sea water then check for a Marine grade.
Then paraffin if you think additional sealing is needed.

The paraffin I have used for sealing Jelly/jam jars is quite pure and non-conductive (at the lower Voltage of batteries).

[Tinkerer]

I would use heat shrink with silicon sealer to seal the shrink tube end and wires.
Silicon sealer works very well. If using around sea water then check for a Marine grade.
Then paraffin if you think additional sealing is needed.

The paraffin I have used for sealing Jelly/jam jars is quite pure and non-conductive (at the lower Voltage of batteries).

Jam sealing paraffin actually is a very good dielectric. It comes in different melting temperature grades. You can find it on aliexpress. Candle "wax" type is generally OK for low to medium voltage.
One problem of all paraffins, is the 10% shrinkage when converting from liquid to solid.

[Hammerhead]

Under water the project was completed