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[daywalkerdha]

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[karlmag]

Hi,

That is a really nice project!

I would certainly want a PCB

Details in PM.

Thank you! :-)
--
Karl Magnus

[peter.mitchell]

I thought i'd link this: http://www.tracopower.com/products/tsr1.pdf

I was wondering if linear or smps so I had a quick look, nice product!

[peter.mitchell]

With a larger power supply you could use a 7805, yes, but you'd need a heatsink and get less than half the battery life from the UPS!

[Psi]

It occurred to me while reading this thread that two of those boost caps in series would work quite well for a raspberry pi ups battery.

Two in series would be 5.2V max and 1300Farrad
The pi draws around 300mA idle so  0.3A/1300F = 0.000230769V drop per second = 0.2V per 15min
So you'd get at least that out of it before the volts dropped a bit low.

If you included a boost converter down to say 2V it would last 5.2 - 2 = 3.2V/0.2V = 16 lots of 15min.
16*15min = 4 hours

4 hours is probably more than most people need, so you could use smaller boost caps to reduce the size of it.

And the best part is you'd never need to replace worn out SLA batteries. (i hate buying new ups bats every 2 years)

[Psi]

There are many sizes but this is the one you see most often.
http://home.comcast.net/~hlandis0/photos/ucap2600f.pdf
You see them come up on electronic goldmine from time to time for ~$10-20 each
They a bit expensive new, so 2ndhand is how most hobby people get them.

I suspect they're used in massive banks of 1000 for high energy physics/research. Every so often they upgrade their cap bank to newer model boostcap. That's when you see lots of 2nd hand ones available.

Because their ESR is so low they will draw lots of current if it's available, so you'd need a charger that is current limited and also voltage limited to their rated volts

[peter.mitchell]

I was going to mention the current draw thing and the price thing and the size thing.

[SeanB]

I want some of those caps...........

Like the UPS you put together.

[peter.mitchell]

There was a point in time where I worked for a company who installed security systems, even the cheapest, nastiest batteries would last 2 years with a full cycle every 3-6 months and a float charge. Powersonic was the cheapest brand we had used without troubles. 12v 7aH Were about $15 a pop in quantity, $20 single.

[SeanB]

Security system manufacturers normally design in a proper power supply, not just a hope it works till warranty is over one. The battery can last over 5 years on one like that, as it is kept at float voltage which means it is always at 95% of capacity, so it does not generate much gas until the one cell decides to go short or open circuit from contaminants in the lead.

[SeanB]

If you want to learn a lot more about battery system design, maintenance and operation you will find a lot of very good papers at www.battcon.com where they have all the archived papers freely available for download. I learned a lot from browsing there, and have found it good to know how cells age, why they have the designs they do and how to use them properly.

[ptricks]

/url]
You see them come up on electronic goldmine from time to time for ~$10-20 each

They had a large amount of them about 2 months ago and someone made a large order and got nearly all of them, wonder what they built .

[Psi]

/url]
You see them come up on electronic goldmine from time to time for ~$10-20 each

They had a large amount of them about 2 months ago and someone made a large order and got nearly all of them, wonder what they built .

It wouldn't surprise me if the geekgroup bought them.

[Monkeh]

/url]
You see them come up on electronic goldmine from time to time for ~$10-20 each

They had a large amount of them about 2 months ago and someone made a large order and got nearly all of them, wonder what they built .

It wouldn't surprise me if the geekgroup bought them.

Don't think so. I imagine I'd have heard of it by now.

[adampielok]

Is it possible to order some PCB's ?

[manu]

Nice project!

[Antoine.]

Hello,
I drew the schematic with KiCad, but I have difficulty with the PCB.
Can you give the PCB, or a more detailed picture of the card.
Thank you.

[magetoo]

Antoine, this project was posted two years ago and the OP hasn't been active in the forum for six months.  It seems unlikely you will get a response.

That said, if it turns out he (or anyone else) wants to pick this up again and make PCBs, I'd be interested.  I have a Pi that I've been meaning to do something with and I really like this idea.

[stryker]

Hi guys

I did buy a couple of these boards for a project that I'll some day get back to.  Will see if I can dig them up this weekend and post a shot of both sides.

Cheers! Geoff

[stryker]

Hello,
Can you give the PCB, or a more detailed picture of the card.
Thank you.

Hi Antoine

I forgot this was a black PCB.  Here's a dropox link to a PDF.  I didn't scan the back since only the drills are on that side.  Aside from the schematics and other links in this thread, I also have this dropbox link to the BoM https://dl.dropbox.com/u/678261/PiSupply_BOM.html

I had asked for clarification on two points: In the BoM R18 is 15k but in the shopping cart it is a 5.1k; and in the BoM R15 is 130k, but in the shopping cart it's 120k.  Daniel's response was

R18 is 15k and R13/R15 are adjustable depending on the batteries (they set the shutdown/cutoff voltages, i used 120/110k)

Cheers! Geoff

[Antoine.]

Hi stryker,
thank you for all.

I will open a topic on my realization

Bye

[Chris Jones]

I guess you may have seen this RPi UPS already, if not it seems to be quite nicely designed:

http://juice4halt.com/?p=6

[GuitarZaan]

Hi Daniel;

I see that this thread is a little dated but your circuit is very nice and I'm interested in a backup for my RPI Sprinkler Controller.
If you've made some boards I'd be interested in purchasing two from you. Any other information would be grand.

Thanks;
Wayne