On 18/10/2010 21:19, John Gardner wrote:
>> a venturi pump - driven by an airline.
> I've used such - They do work, and they do use a lot of air.
>
> Actually efficiency is much worse - Air compressors are not
> adiabatic - Not mine, anyway.
>
> Jack
I think for 0.5 atm a venturi driven by water tap might work!

or a sealed bag with tap (that can join to bag and apparatus) and big=20
spring inside the bag
open tap
press down bag
close tap
release bag
connect to small apparatus
open tap.
close tap when bag has stopped expanding
remove bag from tap
Or two taps.

--=20
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