Seek PCB thinner than 1.6mm

john wrote in news:Xns9BD67FEC64CF2451E7A@195.188.240.200:

AA batteries have to have a bit of space for a spring to adapt to, so the question isn't how thin the board should be, but how easy it is to insert it between ends of batteries. 1.6mm is a bit thick but you already found 0.8 and

0.4. 0.4 is probably ideal. Double sided can be had from RS Components, as a single small board. (Might need to find an account holder if you haven't got one). Sharpen an edge so it slides easily. If you try for anything finer you'll need more than you think, it will need renewing too often.

RS order code: 292-6948 £4.27 plus VAT. (Free delivery if spending over £30 before VAT). It's photosensitised, but just get it. Splitting hairs and agonising over alternative sources is NOT worth the difference between parts of £4 or so. This way you guarantee the surface is in awesome condition too. To get rid of the cladding, peel the plastic film off, expose both sides to sunlight for a few minutes each side, then wash off with a kitchen sponge and dilute caustic soda solution. Ideally, cut strips off it before peeling, so you have a good store. Keep it dry and cold, in case you ever want to use it as the maker intended.

FR4 / G10 sheet

Copper foil tape

I more or less started by experimenting with that approach but I found the two sides got forced apart all too quickly.

Just to be clear, can I explain exactly what I am trying to achieve. It's a bit detailed! :-)

Let's suppose I have a product (such as an MP3 player) and I want to see what the current consumption is in various states such as play, record, low volume, high volume, etc. I want to be able to attach my multimeter leads to a pair of leads about 6 to 10 sinches long which go to my "insertion device". This "device" is what I am posting about. It needs to be thin and to have a conductor on each side; it also has to be strong because sometimes there is precious little movement available to push the cell or cells back.

I have found if the "insertion device" is not strongly made then it will start to split. My preference is for a thin PCB or flexible cable which is already made with conductor on each side. Having to use adhesives can add problems especially if there is any extruded adhesive from the two parts being squeezed together while it is setting. I had initially used some thin tin-coated steel strips from a food can and glued those onto each side of a thin plastic base. Good adhesion has not been easy to achieve.

Of course I could use da fanned out pair of wires with an insulating sheet in between but that is fiddly and slow and never quite so easy because the way some battery compartments are designed seems particularly perverse. Sometimes the cells spring out because the supports are not in line with the cell's axis, at other times the shoulder of the cell prevents the small cap easily reaching the connector, etc I'm sure you know what I mean.

The purpose of building this is to be able to quickly and easily take a current reading.

Oh now that looks close!

I use Farnell because I don't need an account and nowadays they don't charge any extra (delivery or handling or small orders) if ordered on the Net. Archimedes' Lever had posted this link to a datasheet from Farnell and now I can see the same products there that you mentioned.

This led me to this selection table at Farnell:

I'm hoping "4/10" means 0.4mm thick so this one may be right:

I hope it's a good choice because I haven't used this stuff before and I see a lot of alternatives illustrated in that PDF datasheet.

A square inch of brass shim stock, maybe .005" thick, cut into two panels, with a bit of tape to insulate the two , does it fine. It's quick, it's easy, and the first one I made is still around... somewhere.

Yes, we know. You want to sample current from between the two batteries. This isn't rocket science. Let's get back to getting the right media for the job, we already know the goal.

Why not make a dummy battery out of a piece of dowel rod and screws in each end. Use a power supply and measure your current. al

I had an early model Commodore scientific calculator that had an LED display. They consumed quite a bit of power when the display and memories were filled with "8" characters, compared to when only the "1" character was in place. I actually had battery wires, which I could break out and monitor current through. It pulled nearly 800mA with the mantissa and memories filled with "8s". Only about 100 mA with "1s".

No, it isn't. Not if you lock them in place with the Kapton tape, like was said. Oh, and making a 90 degree turn down along the length of the battery isn't a problem either, so it is still the best way to proto it.

All the battery box caps that devices have are tightly mated and would have to remain off the item for the test, unless grooves were carved into their edge.

Not the flexible printed connector strips.

john wrote in news:Xns9BD6C9D1C7F83451E7A@195.188.240.200:

get the RS one, it's more clearly described. If the Farnell decription is correct, it's a single sided paper-thin FR4 board. I've used stuff like it but it won't be useful for your need. I used it to make an LED mounting that conducted heat to a heatsink, it's so thin that conduction is good, if you use a large area of copper. But I wouldn't use it for anything that needed rigidity. 0.4 mm is 400µm, not 35µm. From what I saw of Farnell's listing for all PCB's (not just CIF), there's 0.8, which you saw already, then nothing other than standard thicknesses, or this paper thin one. You could check by phone, ask them if it's a typo for 350µm, or if it really is the paper thin stuff. By the time you get that thrashed out it will have been easier to find an RS account holder.

I have some 0.009 inch thick (rigid) PCB which aint so rigid due to the extreme thickness. How much and what size? I have 3 sheets 4.5 by 6.0 inches, and 7 sheets 8 by 12 inches.

It looks like it, the data sheet and the makers website are unclear on it but they list 16/10 8/10 4/10 and 2/10 (special order) which does correlate well to standard PCB thicknesses, 1.6 0.8 etc...

This 10th thing must be a french thing, to me fractional sizes hint that the unit is inches, but the frech have been using metric measurement for longer and so I find 16/10 being 1.6mm plausible.

the 35u appears to be the copper thickness.

I hink you mean:

Jasen Betts wrote in news:gq7moe$7q7$ snipped-for-privacy@reversiblemaps.ath.cx:

That's what I thought but it's not clear, it directly contradicts a statement a couple of lines away stating it's 2.5µm thick. That second statement looks the most wrong though. Most copper cladding is decribed as weight per unit area too, so the whole Farnel description looks badly confused, maybe from bad translation from French to English. Doesn't matter where it comes from, but RS's stock description is far less ambiguous. (And delivery is free at £20 spend, I said £30 but that was a typo).

Which ain't much for measuring current, which is why my bare FR4 suggestion with Kapton attached conductors would likely yield better results.

IS THAT THE GROOVES OF YOUR BUTTOCKS YOU WANT CRAVED OUT ONLY IF YOU ARE RECHARGING THE BIOSYSTEM YOU FOOL OTHERWISE A CLOSED CAP TEST IS SUFFICIENT YOU ANUS

TWAHAHAHAHAHAHAHAHAHA ! THAT YOU EVEN BELIEVE YOU ARE FIT TO RESPOND TO THE GROUP IS ASSTONISHING TROLL LET ALONE LEAD IT'S MEMBERSHIP

THANK YOUR GOD FOR FAIRY TALES WHERE YOU ARE AS ONE OF LITTLE REAL CONSECUENCE IN LIFE

I AM PROTEUS

Have a couple more drinks, dumbass. We'll be rid of you soon enough. Maybe you'll step out in front of traffic like the guy in the movie "Taken".

Tell us, Mr. Closed Cap Test. Where do the wires for the current reading getinza and getoutza at?