Messages

1

Accessories / Another Alternate Power Solution.

« on: December 14, 2004, 02:12:36 pm »

Hi Ran,

Yep.  When in doubt use Ohm's law!  You've just sparked a few memories from my youth.

I think the calculations for the zener diode configuration are correct, since you're running the load in parallel with the zener it essentially becomes a voltage divider circuit, with the zener sinking any unwanted current.  But, I think the 5W calculation is a worst case scenario that essentially says this is the maximum power this diode will have to deal with if your load goes away and it has to deal with the full 1A of current.

Apparently a better configuration is to have the zener turn on and off a transister in series with a resister.  In this circuit when the zener reaches its threshold of 5V it only has to deal with a few mA of current to turn on the transister, which in turn sits in parallel with the load (or something like that).

For me the zener thing is turning into a pain in the rear so I'm probably going to go with either a 7805 voltage regulator with a small heatsink strapped to the power adapter running on the 7.5V setting, or the straight forward inline 2A silicon diode  that you described.

I need to do a little more testing to find out what I'm comfortable with..... my Z is the backbone of getting me to meetings on time and killing time in those meetings so I want to keep her healthy for as long as possible.

Thanks for your help,

rinsewin.

2

Accessories / Another Alternate Power Solution.

« on: December 13, 2004, 05:38:05 pm »

Hi Ran,

Can you see any issues with the power rating of the diodes you're going to use.  It looks like its easy to get hold of 1A silicon/zener diodes but they only have a power rating of 1W.

According to the sl-c860 zaurus spec its power consumption is 2.7W (I calculated a 5W requirement for the zener diode circuit!!) do you have a similar problem with the 5500?  If, so what diode specs are you planning to use or dont you see this as an issue?

Rinsewin.

3

Accessories / Another Alternate Power Solution.

« on: December 13, 2004, 05:02:59 pm »

Hi Ran,

Can you see any issues with the power rating of the diodes you're going to use.  It looks like its easy to get hold of 1A silicon/zener diodes but they only have a power rating of 1W.

According to the sl-c860 zaurus spec its power consumption is 2.7W (I calculated a 5W requirement for the zener diode circuit!!) do you have a similar problem with the 5500?  If, so what diode specs are you planning to use or dont you see this as an issue?

Rinsewin.

4

Accessories / Another Alternate Power Solution.

« on: December 10, 2004, 11:07:54 pm »

Hi there,

I  just bought a fantastic box of tricks from Radio Shack.  Here are some of the highlights off the box:

  "Multi-Voltage Power Bank.  Power Adapter, Battery Charger"
  "Powers products requiring 3, 4.5, 6, 7.5 or 9VDC and upto 1000mA current"
  "international 90/240VAC auto sensing input - for US and foreign travel"
  Product code: 273-1900
  http://www.radioshack.com/product.asp?cata...t%5Fid=273-1900
  Currently selling for 15 bucks in Oakland, CA.

This little box is great.  Its about the same size as a clamshell zaurus, it has a fold away US style plug and it takes 4 NiMH batteries.  You can use it in different modes: battery charger (using 90 or 240V), AC->DC power adapter, DC power adpater (from the NiNHbatteries).  You can change the output voltage from 3 to 9V and it provides 1A of power.

After a little voltmeter testing I plugged it into my SL-C860 using 4 freshly charged 2500mAh Energizer Ni-NH batteries, and set it to the  4.5V output setting (note: I needed a B style radio shack adpater plug, with the tip set to positive).

The power adapter sustained my zaurus for 4 hours before turning itself off and letting the Zaurus automatically switch to its own power supply (sweat!!!), I ran the following contiously for the 4 hours:

  - Screen on full brightness.
  - Pretec wireless card, with Opera pointing to USGS CA Earthquake website (it auto updates every
    15 or so minutes).
  - MP3 player running in continous loop using head phones.
  - Qtopia clock app
  - note the screen saver popped up every now and again.

This is a little risky since you're charging your zaurus using 4.5V rather than the recommend 5V, but I expect there is voltage regulator (or zener diode)  in the zaurus which drops the voltage down to 3.3V (or something) and these guys normally require that you have at least a 1V delta between your in voltage and output voltage so this is probably right on the threshold.   When I get a bit more time I'm planning on putting together a simple 5V zener diode circuit to drop the 6V adapter output to 5V which will definitely satisfy Sharp's power requirements (but eat up a lttle more power).

Anyway I thought I'd share since the 4.5V output appears to work quite will and gives you an extra 4 hours of high power fun.

Carl C.
Ps. I dont gurantee your results, so please make up your own minds on whether you're happy with the 4.5V or not.... but this is a cool box of tricks!

5

Software / Help: zdebian/keypebble and keymap problems

« on: August 28, 2004, 04:32:32 am »

Hi,

I'm now completely convinced that keypebble is broken... at least of the c860's.  The shift + num characters dont show this is  not only for the debian stuff but also for any vncsession tight, real, tridia you name it.

I've searched for a development area of bug list for keypebble but I can't find anything, has development on this app stopped?

Has anybody else out there had this issue when running keypebble on the clam shell models?  Are there any alternatives?  Fbvnc could be but there is apparently a VT switching bug or something which I cant find any information on either

rinsewin.

6

Software / Help: zdebian/keypebble and keymap problems

« on: August 23, 2004, 04:03:10 am »

Hi There,

I have an SL-C860 with Cacko 1.21b installed.

I've installed the zdebian software from pocketworkstation, and I've been using keypebble to hook into the vncsession (I haven't managed to get fbvnc to work the way I would like).  Everything works fine except for one _really_ annoying little thing........

The shift+number special characters refuse to display in the vncsession ie." !@#$%" etc all default to "12345" etc.  All the other keys are fine just shift and everthing across to top row are screwed up (except  for Del/BS).

I've searched for xmodmap/loadkeys and they dont appear to be part of the zdebian install.  I've tried editing the zvncserver script to pass in another keymap to the Xvnc using the -kbmap arg but I can't seem to get that to work either (it defaults to its normal keymap because it cant find the one I want to point it to).

Has anyone else seen this?  Is this a by product of me using keypebble rather than fbvnc?  How does zdebian/vnc/keypebble deal with keymaps?  Can this be solved or should I give up on the dream of being able to jump between Qtopia Calendar Manager and Mozilla Thunderbird without rebooting?

Thanks in advance for any help,

rinsewin.

7

Deals and Great Z Buys / C860 from PriceJapan.com

« on: August 04, 2004, 01:19:17 pm »

HI There,

Actually my sl-c860 from PriceJapan came with an EA-72 power supply which is rated at AC100V, 50/60Hz which is probably fine for the US but you'll need a step up converter for EU voltages.  According to other threads getting hold of a EA-70 is probably the best way to go.

According to PriceJapan's website for the first year after your purchase they are willing to handle any warranty issues for you in Japan for no extra cost other than shipping, so you'll have to send your device back to them and then they will send it off to Sharp for you.  After a year they will do the same but you have to pay a fee for the service.  Take a look at their website its pretty well laid out.

rinsewin

8

Deals and Great Z Buys / C860 from PriceJapan.com

« on: August 04, 2004, 02:47:48 am »

I highly recommend shopping with PriceJapan.  I ordered my SL-C860 on Fri 7/30 for $619 all in (including a 3% paypal crdit card fee), I recevied an email back from them at 7:45am (Tokyo Time) stating that my order was going to be shipped in 4hours.  Sure enough four hours later I recieved an email with a DHL tracking number. The package arrived in Oakland, CA at 11:15am on Monday morning..... Now that is service.

I asked them to write gift on the customs declaration but they went one better and stated that it was a $150 Electronic Dictionary.... well I guess the Japanese version could be a dictionary  

It took around 4 hours to charge the battery and then around an hour to convert it completely to English.  The hardest part was getting XP (running in vmware) to install the 5500 QtopiaDesktop with the SL-C860 drivers from the Japanese CD and then guessing which Japanese Menu on the Zaurus represented a Direct USB I/O connection..... it got upset with me a couple of times but we managed to work through our mutual communication problems and I soon had the terminal installed.   Oh, yeh... one think to note is that there is a screenshot missing from the various notes on converting to English.  There is a  screen between the Japenese please wait 1 minute screen and the calibration screen.... I sat for a good 10 mins looking at the thing waiting for something to happen before I started pressing keys. It progressed to the calibration screen once I touched the screen I guess this is like the Palm's "please tap the screen aware" calibration step.

So now I'm just waiting for my HSN Pretec wireless card, and 512MB SD card from buy.com....  all oredered at the same time as the Zaurus, the Japanese are so efficient   .  Oh, I highly recommend reading through fatwallets complaints about buy.com before using them.... I didn't and now my order has disappeared into their black hole of a warehouse never to be seen again until the rebate timeframe expires.

This little gizmo is SOOOOO cool!

rinsewin