Thinking within the box

[manuka]

It's often the boring things now in electronics that blow budgets - cases/switches/rubber feet/screws etc. Hi tech is cheap but can look ugly if left bare! Here in NZ the every lowering price of basic smart phones is now almost matching the increasing price of their protective cases-this no doubt also holds in the rest of the world too.

With this trend in mind I've recently been pondering cost effective project "finish", especially based around diverse AA switched battery boxes. I'd explored this some months back with a 3 x AA box housing a 11 x 12 hole breadboard offcut. See =>http://www.instructables.com/id/Single-AA-LiFePo4-cell-powered-project-in-a-parti/.

Further brain storming & mockups show a partially gutted 4 x AA box as perhaps more appealing. If run from a single 3.2V LiFePO4 ("LFP") cell these larger boxes will neatly house a slightly trimmed (20 x12 hole) solderless breadboard or Kiwi Patch Boards in the liberated 3 cell spaces. For versatility a 2 x AA alkaline supply could be used, but the 4 x AA box would then only house an "outside in" centre rail circuit board in the 2 spare cell spaces. Programming points could be fitted on the board (as here), or run to a 3.5mm stereo socket mounted where the box supply wires normally emerge.

Naturally LFP cells will eventually need (smart) recharging, but a white,pink or blue LED makes a handy supply measure. These run brightly on 3-3.2V but dim & eventually fail to light by 2.5V. This near perfectly matches the "time to recharge" lower limit of a LFP cell.

Thoughts welcomed - Stan.

 

[Paix]

You are of course spot on about the cost of a casing Stan and I am guilty as charged, having naked bits of circuitry residing/hiding all over the place in a state of incompleteness.

Certainly something to think about for those small gizmos that need to be compact. A good idea, well worthy of consideration and with a LiFeP04 cell a darned good idea.

You seem to be a lot more upbeat about LeFePO4 batteries than IATA and the postal services have been of late, but it just goes to show that we need to be growing more cabbages for their chemical content. Not as much cabbage coloured as Green - to parody an old saying.

 

[manuka]

Paix: Thanks for the feedback- appreciated! I'm from British stock but your "cabbage" saying rather escapes me. By chance however element 39 Yttrium (which is used in higher performance LiFeYPO4 cells) is found at significant levels in cabbages!

I may seem one eyed about this, but (no doubt arising from my mixed educational/marketing/electronics career) I've an increasing aversion to messy wiring & naked construction. Aside from presentation,safety & IP (Ingress Protection) such exposed circuitry may increasingly be considered mere e-junk of course & even discarded by ones family,workmates or school ...

A couple of followups below. Am I the only one who trims breadboards to suit? Stan.

 

[eclectic]

"Not as green as you're cabbage looking."

However, I'll leave Ian to explain the more
gnomic aspects of his post.

e

 

[SAborn]

Am I the only one who trims breadboards to suit?

Perhap you are one of few who builds a finished circuit on breadboard. (they are rubbish i think other than for testing a circuit theory)

I often design my boards to fit the Jaycar cheap little black jiffy boxes, then drill the screw posts down lower so the board sits on top of the screw posts and is retained with the lid and screws through holes in the board into the posts.
This way the bottom of the jiffy box becomes the top, allowing for holes to be drilled for leds, switches etc.

A quick paper printed label laminated and stuck to the box makes it look rather neat, i often punch a hole in the paper label for leds etc before laminating, so the leds can remain inside the box and the lamination gives a clear little window for the leds to shine through, whist keeping the box somewhat sealed by the laminate.

I have also used the battery boxes like you use to house FM bug transmitters in the past. (but not on breadboard)

"Not as green as you're cabbage looking."

Thats an old saying i remember from a very young age. (perhaps Stans younger than we think )

 

[manuka]

Perhaps you are one of few who builds a finished circuit on breadboard

Never-my past students used to say I was a soldering & PCB fanatic! My first few decades in electronics (1960s-70s valve/tube & early semiconductors) were characterised by almost EVERYTHING being soldered up. That was when radio transmitters were the size of filing cabinets & soldered tag strips abounded for even MW band crystal sets.

These days I've increasingly stressed as an educator that modern circuits should first be wrestled with at the breadboard level. Sadly SO many folks (especially newbies) still just rush in & solder up something on a DIY PCB or-argh!- Vero board before they're much idea about the action,layout, current drain,stability or such basics as switches,supply provision or enclosure. Hours/days later it may all end up in the bin...

Hand soldering is a craft in it's own right anyway & it takes many folks months to become suitably skilled. By that time leraners have become so disheartened with their wonky soldered circuits that they may GIVE UP on electronics since "nothing they make ever works". Many schools lack dedicated rooms to remove flux fumes or protect from hazardous lead. Even protective benches & support stands may be lacking - burns & equipment damage can be common. Etchants are corrosive - I'd a lab stainless steel sink ruined by student's Ferric Chloride discards.

And let's also be realistic & recognise that today's fast moving game means many soldered up boards may rapidly become obsolete too. In the last decade I must have made dozens of ever advancing 433 MHz data units alone - many on breadboard that were quickly modified to suit fresh modules.

Breadboards are versatile & my experiences show that learner's circuits made with them have a higher success rate than soldered versions. They're great confidence boosters & certainly not rubbish! I was initially hesitant about them too (1970s) but the massive industry use of non soldered connectors/CPUs/RAM etc in consumer electronics showed sockets (in all their forms) are very much mainstream. You can open up a modern laptop or smart washer & be bedazzled- there are almost more "dry" connectors than components! Stan

 

[Paix]

Not so cabbage looking as Green - It was a parody on the familiar saying that was well recognised by Eclectic and Stan who was spot on with the Yttrium, use and it's possible source from cabbages. It's good when the cryptic/oblique humour decodes as intended. I don't suppose that anyone would sort of consider that to be a Green source of the chemical. Probably not once the processing was taken into consideration, but a lad has to have some poetic latitude.

I haven't considered pruning breadboard to size, but then I have mainly the smaller types and some that are a dainty 17 x 5 + 5 contact strips and thought about swapping out some or all the contact strips for crimp terminals with a view to making a small pin/patch board. Only in my mind as yet, like so many of my good ideas, equipment enclosures included

I look at so many things and try to think what I could use them for. I suppose that in many ways the Picaxe series of MCUs are almost a personification of this particular paradigm.

 

[SAborn]

Stan,

I was ratteling your cage a little due to the low response of replys.
I still dont like bread boards that much, but do understand their educational advantage, but also think being exposed to burnt fingers and dry joints whist building a circuit is a important skill to learn.
So the next generations also learn to construct a PCB as we have done, not every solution is on ebay just yet, even though breadboards come close.

Education should be as much about exposure to techneques and physically working with tools to build a project as the electronics involved.

My early years at high school, showed me the basics of designing a circuit board, producing a exposure to a pcb, develop, etch, drill and solder a board, all with very basic stuff to todays standards.

It showed myself and many others how simple it is to produce a circuit and PCB to suit.

I often think todays education is more about success of a project than the knowledge to make the project from scratch.
Are we just becoming a plug abd play eduaction system,? i would hope not.

 

[manuka]

Times have changed. Half of what you know may be redundant in 5 years, while half of what you need to then know has yet to be released. Numerous traditional hardware approaches are now better explored & organised by cheaper & more versatile software,with SDR (Software Defined Radio) typical.

I'll perhaps rest my case by reference to Andrew Hornblow's ~decade old PICAXE Picasa resources,which (in conjunction with his esteemed Kiwi Patch Boards) have long given immense benefits to PICAXE e-learners. You have to applaud his "no parts" circuits!

For those (like myself) who are being increasingly taken with state of the art approaches,Andrew's recent RPi/PICAXE "Pi-AXE" hybrids look especially worthwhile. Stan.

 

[manuka]

Australia's "Silicon Chip" monthly now intend this approach as an article in their Feb. 2014 issue, with the timing to suit the new down under 2014 school year. Our talented OhmArt artist has provided a VERY sharp cartoon, & a "20 x10" PEBBLE design template has also been rustled up.

Jaycar's HP9558 based "finger" ("thumb" ?) has shown itself ideal for many intro. ~3V powered circuits,be they PICAXE, DIP IC (555/logic etc) & classic DANDY (Discretes Are Not Dead Yet). There's perhaps scope to mass produce/silk screen such boards in fact? I've focused on a single 3.2V LiFePO4 cell supply, but there's room in a 4 x AA box to instead allow powering via traditional 2 x 1.5V alkaline cells.

Further opinions,insights,resources & circuits etc appreciated (& naturally credited)- follow up ideas will be hosted at =>www.picaxe.orcon.net.nz/bbox.htm Stan.