16-02-2014, 08:59 PM
I've done some pondering and pottering.
As has been pointed out the Lithium Cells leave very little material in a 15mm Enclosure, although they could be stacked the other way round. Also, the Voltage characteristics of them leaves a lot to be desired in this effectively Constant Voltage application. Finally, Capacity isn't really a problem as I don't expect it get much use.
In the end I settled for LR69 Alkaline Cells. I would have preferred the Silver Oxide version - SR69 - but the price is prohibitive.
They're 9.5mm Diameter by 2.1mm Thick, so there's more margin on the Diameter and 20 are a more sensible fit in the length available.
The Diameter is near enough 3/8" so I drilled a hole in a bit of 19mm Nylon and fed them in. It's an interesting task getting them all in the right way round as they're very slippery. I only dropped 2 but managed to find them.
So, what to make a rectangular enclosure out of? In the end I settled for a chunk of 15mm Cast Acrylic. I chopped a couple of 25mm pieces of with my trusty Denbigh Donkey Saw, shortened them to 60mm and cleaned up a bit. They fit OK.
After that it was just a matter of setting them up in the 4-Jaw and drilling though, slowly.
I think they look quite pretty
Now I have to think about the ends. One end can be glued but the other end I want to be removable. I haven't decided how yet.
Alan
As has been pointed out the Lithium Cells leave very little material in a 15mm Enclosure, although they could be stacked the other way round. Also, the Voltage characteristics of them leaves a lot to be desired in this effectively Constant Voltage application. Finally, Capacity isn't really a problem as I don't expect it get much use.
In the end I settled for LR69 Alkaline Cells. I would have preferred the Silver Oxide version - SR69 - but the price is prohibitive.
They're 9.5mm Diameter by 2.1mm Thick, so there's more margin on the Diameter and 20 are a more sensible fit in the length available.
The Diameter is near enough 3/8" so I drilled a hole in a bit of 19mm Nylon and fed them in. It's an interesting task getting them all in the right way round as they're very slippery. I only dropped 2 but managed to find them.
So, what to make a rectangular enclosure out of? In the end I settled for a chunk of 15mm Cast Acrylic. I chopped a couple of 25mm pieces of with my trusty Denbigh Donkey Saw, shortened them to 60mm and cleaned up a bit. They fit OK.
After that it was just a matter of setting them up in the 4-Jaw and drilling though, slowly.
I think they look quite pretty
Now I have to think about the ends. One end can be glued but the other end I want to be removable. I haven't decided how yet.
Alan
