I've lurked on the forums for some time now, and have assembled a PWM3F which I hope to test soon. =)
Here's a few thousand words on how that went:
Parts:
Tools/Setup:
1/2 Done:
All Done:
I noticed the 8-leg IC socket wasn't on the parts list, and I forgot to order the smallest precision cap from Digi-key, but the local instrument repair/fluke dealer seemed to think he had a suitable unit.
Without knowing a great deal about how to shop from an o-scope, I ended up picking an owon PDS-5022S from eBay. Shipped from China for a ton of money, but ended up at my doorstep in 3 days.
It's LCD response time is really bad, so measuring non-repeating waveforms isn't very impressive, (like sampling audio output from the soundcard), but stable, repeating waves are nice and bright, and the unit is quite portable.
For a cell plate stack, I had an idea of using conical sections of 316 stainless, and wanted to post them to everyone for their thoughts, especially given my extremely limited knowledge of pressure/hydraulics/etc.
Here's a few thousand words first:
In a nutshell, the idea is to use the gas being produced at the base of each conical section, rising towards a hole in the very tip of each cone, as the dielectric separator between cells, with return water pressure dribbling down each plate. This pressure could likely be achieved by extending the tubular housing vertically and use gravity to create the downward water pressure to re-fill each cell in a drip manner, but maintain seperation from each other from the rising bubbles. To ensure the plates didn't touch, and were water-tight, small strips of plastic/pvc/whatever would be glued to the top of each cone, then the stack would be assembled with a ring of silicon or other sealant around the edge before the next cone is placed. This would make the cone stack water-tight around the edge, and against the tube wall.
These wireframe renderings are to scale of 6"dia cones in a 4' tall tube.
At first, this idea seemed like way too much hassle of trying to size and gauge each cone-tip hole, but then I thought of 3 possible benefits if it worked out:
1) No moving parts for cell refill
2) Have the ability for a single fill point, with possibility of a circulation pump w/a filter, radiator perhaps?
3) Could be safer if backflash were get into the cell, as it's a bubbler by design.
In this proposal the million dollar questions are:
1) What size should each cone-tip hole be?
2) Should all cone-tip holes be the same size?
... I imagine the would need to be sized in an increasing scale, smallest on the bottom, largest on the top as each cell's gas will contribute to the next.
3) How could you make these cones?
I haven't worked much with stainless, however, I imagine you could start with a plate slightly larger that 6", drill a small hole in the center, then attach this plate to a drill press on it's slowest speed, then use a plasma cutter to make a precision circle whilst spinning on the drillpress. You then have a near-perfect disc with a centering hole.
The next step would be forming consistent cone shapes, for this I had envisioned making a ceramic mortar and pestle type press, although someone reading this might have a much better idea.
This press would have the positive of the cone mounted on a standard garage bearing press-fit machine, with the cone negative on the base.
The top cone could have a machined centering pin to ensure the plate was evenly pressed, and perhaps a lubricant could be applied to the press surfaces to make sure even pressure would be applied.
Here's a thousand words:
In closing, I would like to thank you, Mr. Bob Boyce for sharing your circuitry, and tutorial for assembly. I hope this post might demonstrate good faith that I'm experimenting for my own goals, and providing useful information back to the community. Bob, if you happen by this post, and find it in your heart to share the hookup diagram for the PWM I would be extremely grateful and excited to use it to test my cone plate stack idea.
Thank you all for the outstanding information and excitement on this forum.
e.m.a.i.l: oupower ( a t ) B i n a r y b u d d h a ( d o t ) c o m
