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Messages - gromituk

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Cxx0 Hardware / Probably Fried The Charging Circuit
« on: September 06, 2011, 12:30:50 pm »
Quote from: arzgi
Can someone who has deeper knowledge of electronics tell what was wrong?
A bicycle dynamo is a current source rather than a voltage source.  Its current is proportional to its speed, rather than its voltage.  This means that as its speed rises, it will want to push out more and more current (until it self-limits due to its impedance increasing with frequency, as it is inductive), and will produce more and more volts to do this.  You therefore must ensure that the current it wants to produce is always absorbed.  Unless your Zaurus was trying to take all the current that was available, the voltage at the input side of the voltage regulator could rise to a level at which the voltage regulator would fail, and these things tend to fail short circuit, dumping that high voltage straight into the Zaurus.  What you should have installed was a shunt regulator such as a zener diode of, say, 10V across the input to the regulator (which would have to be quite a high powered zener to dissipate 3W).  Some bicycle lamps have two back-to-back zener diodes in them to prevent blowing the bulb at high speed.

Did you fit a smoothing capacitor before the regulator?  If not, you meter may have misread completely because it was trying to measure a relatively high frequency pulsating DC, rather than a smooth DC.  Who knows how the voltage regulator might have performed under those circumstances, too.  And it needs a non-electrolytic capacitor on input and output to prevent oscillations.

Zaurus - pdaXrom / How To Remove
« on: August 22, 2007, 04:39:04 am »
Thank you!   I'll try again this evening.

Zaurus - pdaXrom / How To Remove
« on: August 21, 2007, 06:34:42 pm »
Put this file on a CF-card, insert the card in your zaurus and then enter the Diagnostic Menu as described earlier. From the Menu choose "NAND-Restore" and follow the steps,
I've just tried to do this.  I get a screen saying

"NAND Restore from CF
not exist file"

The file (from Trisoft) is at the root of a 256MB CF card which is reported as vfat.  I had trouble getting the all-uppercase filename (had to mount with option "shortname=mixed") but it still isn't found.  Any ideas please?

Zaurus - pdaXrom / Usb Power Injection Fix For Usb Devices
« on: July 01, 2007, 05:40:18 pm »
Rather a naive implementation, using a 5V linear regulator with a 9V supply, which will be very inefficient (i.e. eating batteries unnecessarily).  The advice with 78xx regulators is also to connect a decoupling capacitor close to input and output to avoid oscillation, and this is not done here.

I'd just go with four NiMH rechargeable cells in series, giving 4.8V or so - close enough.  It would be wise to wire a fuse into the circuit.

Zaurus - pdaXrom / Is Your Z "dead" After Trying To Install Pdaxrom?
« on: June 16, 2007, 10:23:45 am »
Thank you very much for this thread - I thought I'd bricked my 860 when I installed u-boot and it didn't re-boot.

One thing to report: I couldn't get the emergency system to see anything on my CF card (i.e. the nandlogical commands in the install guide) until I mounted it manually with

mount /dev/hda1 /mnt/cf

It may have been because the card was in when I applied power.  Hope that helps someone.

Zaurus - pdaXrom / New Releases Bugs/issues And Fixes (plz Post!)
« on: April 18, 2007, 06:46:05 am »
Admittedly I am no linux guru or hacker
I see that as a positive benefit, because gurus, however well-meaning, can always find it hard not to take for granted that others will know about things which they see as elementary.  The documentation for a project is just as important as the project itself, and is where open source often fails miserably, so you are doing vital work - well done.

Zaurus - pdaXrom / Audio Always On?
« on: January 28, 2007, 03:36:01 pm »
If you mean a tiny click when you plug them in, then that doesn't mean much.  Headphones are very sensitive and you can hear a very small current flowing.

Zaurus - pdaXrom / Forward Motion In Pdaxrom
« on: December 06, 2006, 03:06:30 pm »
Late - not my name... just "Later" with out the "r" :-)  <~ I'm debating on making a pinned thread just stating this :-)
[div align=\"right\"][a href=\"index.php?act=findpost&pid=148279\"][{POST_SNAPBACK}][/a][/div]
I think it might just be easier to abandon your rather odd "signature"  

Zaurus - pdaXrom / Any Hope?
« on: November 01, 2006, 04:48:19 am »
The codebase for these clients and the SL-C3k Zaurii is shared and open source.
That'll make a change...  

Zaurus - pdaXrom / Openbox Vs. Matchbox As Window Manager
« on: October 27, 2006, 09:25:13 am »
Have you tried Rox?  Details (and other useful snippets) can be found here, including config lines:

There's quite a bit about alternative window managers on this forum.

As far as I can tell, there is no answer to question 3.  

Zaurus - pdaXrom / Wip Static Recompiler For 8086 At Zaurus C860
« on: September 18, 2006, 12:21:08 pm »
Oh right! I've never heard Hilary as a guys name before- sorry! 
You're from the UK, and you've never heard of Hilary Benn?

Zaurus - pdaXrom / Beta 3 Fixes, Customs, Contrib
« on: September 17, 2006, 08:22:24 am »
Also abiword doesn't work for me on my 860 unless I install

I'm having trouble with meanie's feed - the package manager doesn't like it so I have to use wget and install manually.

Zaurus - pdaXrom / Beta 3 Fixes, Customs, Contrib
« on: September 17, 2006, 07:14:12 am »
Thanks for a great site.  Whenever I update my ROM I always forget essential things so it's good to group them together.

A couple of small points:

1) It would clarify things a bit if you point out that the feed addresses are in the left hand column;

2) You mean backslash instead of forward slash in the SNES emulator description.

One essential thing to add for me with an 860, and possibly all 7/8 series users, is a bugfix for a nasty offset to the pointer (not the arrow, but the part of the screen it affects, oddly) at the top right:

Zaurus - pdaXrom / Gpflash Install
« on: September 17, 2006, 05:21:08 am »
If all it's upset about is removing a file, how about trying to create it with touch?

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