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This is an archived, read-only copy of the United-TI subforum , including posts and topic from May 2003 to April 2012. If you would like to discuss any of the topics in this forum, you can visit Cemetech's Calculator Hardware subforum. Some of these topics may also be directly-linked to active Cemetech topics. If you are a Cemetech member with a linked United-TI account, you can link United-TI topics here with your current Cemetech topics.

This forum is locked: you cannot post, reply to, or edit topics. Calculator Modifications => Calculator Hardware
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DigiTan
Unregistered HyperCam 2


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Joined: 10 Nov 2003
Posts: 4468

Posted: 27 Apr 2006 12:13:50 am    Post subject:

Calc Dual Battery Switchover

This project is for anyone who's ever lost a Pgrm during a battery change; or gave up a high score because the screen was too dim. The fanbase for dead batteries and dimming graphics is a very small one, which made me happy to annouce the completion of project Calc DBS -- or Calc Dual Battery Switchover.


TI-82 during 5-hour Phoenix Marathon

This is a product-improvement on 2004's EED project. For those unfamiliar, it's a power management system that is attached to the calculator. Putting the "D" in "DBS" is the option to use AAA batteries, AA batteries, external power or any combination of the three. So whether you use regular batteries or rechargables, Calc DBS helps you save trouble and look good doing it. The original perks are still here:

Benefits:
* Indefinate gameplay
* Over x3 more time between battery replacements
* A screen that never flickers on keypresses
* Graphics that never blur
* Ability to power other hardware mods
* Built-in chick magnet

Improvements on the original

The original EED used automatic switching when external power was added or removed. This was done electromechanically with much success, however the switching allowed a 1/1000th second period in which the calculator would receive no power. That would cause your calc to reset if you forgot to turn it off when unplugging or inserting the cord.

Thanks to a new DMOS switch, Calc DBS switches over 52,000 times faster than EED. The new switch also allows a constant supply of power when it's between the "on" and "off" states, so there is no known chance of a reset. DBS also has a small amount of reserve energy, that has a number of direct advantages.

Any DC adapters between of 8 and 27 Volts will completely take the workload off your batteries. Lower adapter voltages of 3 to 8 Volts will assist the batteries and extend battery life by a slight amount. Otherwise, when there's no external power, your AAA and AA batteries will work together, giving you less screen flicker, high speed, and wickedly dark contrast.

Features & Interface

The status LED (shown in orange) indicates when external power is present, and it is now front-mounted instead of on the side. Next to that is a surge-protected DC adapater socket and a very tough 2.5mm linkport. The DC port can take power from wall adapters, cigarette lighters, car batteries, USB ports, a hampster wheel, it won't matter. Sources above 27 Volts are rejected automatically.

Summary & Upcoming

I'm working on a detailed guide and parts list for the system that will be published on my site, ticalc, and possibly UnitedTI. Calc DBS may also have a limited ability to recharge NiCad batteries. This has not been confirmed, but will be looked into.


Last edited by Guest on 27 Apr 2006 12:23:18 am; edited 1 time in total
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elfprince13
Retired


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Joined: 11 Apr 2005
Posts: 3500

Posted: 27 Apr 2006 12:41:48 am    Post subject:

/me drools.
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leofox
INF student


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Joined: 11 Apr 2004
Posts: 3562

Posted: 27 Apr 2006 08:36:55 am    Post subject:

Wow thats awesome.. Not that i will ever be able to assemble such a thing..

Cant you send me one from Texas? Razz
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DigiTan
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Joined: 10 Nov 2003
Posts: 4468

Posted: 27 Apr 2006 04:20:47 pm    Post subject:

Heh heh. I don't see why not. Cool
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alexrudd
pm me if you read this


Bandwidth Hog


Joined: 06 Oct 2004
Posts: 2335

Posted: 27 Apr 2006 04:45:46 pm    Post subject:

Seems like everyone is coming up with a great way to make money.

Sounds great, are there any pictures from different angles?
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leofox
INF student


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Joined: 11 Apr 2004
Posts: 3562

Posted: 28 Apr 2006 08:50:43 am    Post subject:

DigiTan wrote:
Heh heh.  I don't see why not. Cool
[post="77277"]<{POST_SNAPBACK}>[/post]
Maybe because shipping to the US is VERY EXPENSIVO?
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DigiTan
Unregistered HyperCam 2


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Joined: 10 Nov 2003
Posts: 4468

Posted: 28 Apr 2006 05:06:26 pm    Post subject:

Shhhh. You're ruining my sales pitch. :P

alexrudd wrote:
Seems like everyone is coming up with a great way to make money.

Sounds great, are there any pictures from different angles?
[post="77286"]<{POST_SNAPBACK}>[/post]


I can get some in a few days. It's really tricky because my camera has such low resolution, it's tough to get a detailed shot of the whole calc. I think the lens is fixed too.


Last edited by Guest on 28 Apr 2006 07:46:28 pm; edited 1 time in total
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DigiTan
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Joined: 10 Nov 2003
Posts: 4468

Posted: 21 Sep 2006 08:57:22 pm    Post subject:

Still haven't gotten around to putting the schematic into CAD, but I did manage to find the original plan-on-paper diagram. Besides apologizing for the sidewaysness of the pic, I'll note R3 and R4 were re-calculated after the fact and I'll post those values this weekend.

For a design using so few parts, the performance is highly stable--and operated on the same breaker as industrial equipment this past summer with no problems. The only limitation is: any adapter voltage above 18 volts will require a heatsink on the regulator (marked "78L06").

In addition to this "universal" version, I'll post up a low-power version that can be powered via USB port and other small sources. More updates later.



Last edited by Guest on 21 Sep 2006 08:58:27 pm; edited 1 time in total
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todlangweilig


Advanced Member


Joined: 14 Feb 2006
Posts: 470

Posted: 22 Sep 2006 11:58:48 am    Post subject:

Sweet, you finally got it done Smile Can't wait to see what I can do with it.
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Raster


Active Member


Joined: 17 May 2004
Posts: 529

Posted: 22 Sep 2006 08:41:53 pm    Post subject:

Nice DigiTan, once I get back home, I will probably build that for my calc :biggrin: .
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AlienCC
Creative Receptacle!


Know-It-All


Joined: 24 May 2003
Posts: 1927

Posted: 23 Sep 2006 01:52:09 am    Post subject:

Digitan when I saw the title "Calc DBS" I was getting excited, thinking a relation Database for the TI. Then I saw this, while very cool, was nothing of that nature...how misleading. ;)

--AlienCC
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DigiTan
Unregistered HyperCam 2


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Joined: 10 Nov 2003
Posts: 4468

Posted: 23 Sep 2006 05:45:28 pm    Post subject:

I guess all the good acronyms are already taken. Very Happy

As a side note, I got all the parts in for the external memory function. It's probably not as big a deal now that msd8x is out, but I'll be doing a similar project anyway so; might as well. Mem size will be 64kB with the current hardware. Might also look into that Universal Translator idea from way way back.
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elfprince13
Retired


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Joined: 11 Apr 2005
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Posted: 23 Sep 2006 06:18:09 pm    Post subject:

Digitan, has anyone told you that you are insanely cool recently? because they should. this awesome, keep at it.
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DigiTan
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Joined: 10 Nov 2003
Posts: 4468

Posted: 23 Sep 2006 08:50:14 pm    Post subject:

Yeah last year I was fall-down broke. Thanks to a lot of hard summer work I can finally finance some stuff again (no more chasing $1's in the parking lot). That reminds me, I need to put in a UTI donation. Cool
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elfprince13
Retired


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Joined: 11 Apr 2005
Posts: 3500

Posted: 24 Sep 2006 11:23:20 am    Post subject:

DigiTan wrote:
Yeah last year I was fall-down broke.  Thanks to a lot of hard summer work I can finally finance some stuff again (no more chasing $1's in the parking lot).  That reminds me, I need to put in a UTI donation.  Cool
[post="88853"]<{POST_SNAPBACK}>[/post]



I remember you moral dilemma over the cash in the parking lot.

definitely good that you can finance your projects again since you are probably the only ti-hardware-modder left
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DigiTan
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Joined: 10 Nov 2003
Posts: 4468

Posted: 25 Sep 2006 03:11:16 pm    Post subject:

Found out today it withstands having the power cord yanked from the wall -- even in an ASM prog. Bad for crashed ASM games, but good for everything else.

[edit]
R3 = 47k
R4 = 100k


Last edited by Guest on 14 Apr 2007 09:21:24 pm; edited 1 time in total
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DigiTan
Unregistered HyperCam 2


Super Elite (Last Title)


Joined: 10 Nov 2003
Posts: 4468

Posted: 14 Apr 2007 09:34:26 pm    Post subject:

Hooray for digital camera clearances! This pic of the Alpha-10 titlescreen was taken next to the transceiver at the university ham station. Also shown is my carrying case for the Calc DBS wall adapter (left).



Due to progress in an unrelated project. I *might* try to upgrade Calc DBS once more. Some options I'm looking into are (1) an attional battery supply to augment the current AA and AAA's, (2) external flash, (3) option to power calc from a USB port, (4) a reset switch in case your ASM game crashes. There's a couple other options that are less likely.

Anyway, the Calc DBS is nearly 1 year old now and I've had no problems with it to date. The year also required only one battery replacement, despite my love for cheap, generic battery brands; and many game marathons with ZTris, Phoenix, Mario, Slippy and other favorites. Cool


Last edited by Guest on 14 Apr 2007 09:39:46 pm; edited 1 time in total
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frenchcalc1
جان ألعريم


Active Member


Joined: 14 Mar 2007
Posts: 648

Posted: 15 Apr 2007 12:51:02 pm    Post subject:

Dude, that looks awesome! how long do your batteries last with DBS?
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DigiTan
Unregistered HyperCam 2


Super Elite (Last Title)


Joined: 10 Nov 2003
Posts: 4468

Posted: 16 Apr 2007 07:05:31 pm    Post subject:

I never got around to timing it like I originally planned. But at the time of development, I estimated it at nearly 24 hours when AA's and AAA's are used.
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R3D_bull43


Newbie


Joined: 19 Jan 2008
Posts: 5

Posted: 20 Jan 2008 11:18:12 am    Post subject:

so does just work for the TI-82 or can it work for a lot of 8x's? maybe like a 83+? this is awesome :biggrin:
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