A little out of the box

[BVnursery]

Ahh yes... birthday time !!    and the joy of finding 'the' gift.

Found the gift...  and got to thinking..  sure would be nice to have a blue led shining up
through the water pool,  lighting up the focus area of the sculpture.

DIY pointed me to a quick and simple 110VAC to 3.3VDC converter.  The parts I had floating around werent exact matches to what was suggested but sure did work nicely.

The led was mounted in a 'thru-hole' strain relief with a cutout for the led leads. That was epoxied to the bottom of the pool.   The leads then followed the power cord of the pump out of the unit to a rubber covered quick disconnect.  The rubber boots were alligator clip covers and fit the disconnect very tightly.  The converter was placed close to the male
AC plug.

[cadstarsucks]

Ahh yes... birthday time !!    and the joy of finding 'the' gift.

Found the gift...  and got to thinking..  sure would be nice to have a blue led shining up
through the water pool,  lighting up the focus area of the sculpture.

DIY pointed me to a quick and simple 110VAC to 3.3VDC converter.  The parts I had floating around werent exact matches to what was suggested but sure did work nicely.

The led was mounted in a 'thru-hole' strain relief with a cutout for the led leads. That was epoxied to the bottom of the pool.   The leads then followed the power cord of the pump out of the unit to a rubber covered quick disconnect.  The rubber boots were alligator clip covers and fit the disconnect very tightly.  The converter was placed close to the male
AC plug.

Well we are all a little out of the box, aren't we.  No that's not right...we are all a little out of our minds! 

On a note that everyone will appreciate: I was telling you about http://www.a123systems.com/newsite/index.php Li rechargables.  The seaboard sales manager stopped by today.   The 18650 cell should be available from their site  late Q3. 

1.1AHR,
30A continuous discharge rating (70A PK),
3.3V float charge to 90% capable ( read you can charge it directly from a 3.3V linear regulator,
the design kit of 6 cells should be about $60.  roughly $10 ea, $8 ea @1K
intrinsically safe ( read won't burst into flames )

I was telling you about the 26650 which you looked up on their site that was $20 ea and $16 @ 1K for a 2.2AHR 60A continuous and 100A PK.  Which I am repeating mostly for the sake of the other readers.

Dan

[justDIY]

1.1ah for a 18650 sized cell is pretty weak, but the rest of the specs are outstanding!

[cadstarsucks]

1.1ah for a 18650 sized cell is pretty weak, but the rest of the specs are outstanding!

That is true until you remember that there is no special circuitry required to prevent it from bursting into flames and you can draw 30C from it. 

They are interesting from the standpoint of not needing protection circuits unless you plan on really hammering them...regular lithiums you can not even buy, hell, I can't even buy them-they are only sold to certified battery pack companies to ensure that they are paired with proper safety circuits. 

Even when you buy a "single cell" you are actually buying a pack with protection circuits built in.  Those circuits kill the pack if it is over discharged, over heated, or what ever in an attempt to prevent it from going into thermal runaway.

Dan

[justDIY]

hmm

I just bought some 2.6 AH cells made by LG - no electronic safeties built in (they do have double wall steel cylinder construction with pressure reliefs.)

The protection circuit I bought with them is absolute rubbish ... its latching in nature and requires all load to be disconnected from the cell before resetting ... even a piddly 15ma draw from an LED kept the under-voltage protection circuit active, preventing the cell from recharging.