2014-12-15

Zap&Go better than power bank

What I am going to briefly describe today, is called Zap&Go charger.




It looks like a battery bank, but it has a graphene supercapacitor instead of a LiIon battery!
Here is the comparison.

Zap&GoPower Bank
Charging bank from socket5minSeveral Hours
Number of cycles>10000<1000
Capacity drop in timevery lowhappens sooner or later
Temperature toleranceworks fineloses capacity
Deep discharge toleranceno problemcan damage battery
Charging phone timeNormalNormal
Self-dischargeNormal?Normal
Price150$~30$
Capacity~1500mAh>3000mAh (for this size)

Charging bank from socket - the main advantage of the Zap&Go is that the supercapacitor can charge quickly, with good electronics to control the charge. Bear in mind that for this fast charge your socket should be able to provide over 3KW of power. i.e not suitable for shaver sockets!

Number of cycles - normal power banks have LiIon batteries which are limited to several hundred cycles of charge/discharge. Low quality batteries barely reach 100-200. Supercapacitors should have practically unlimited number of cycles. And their capacity drops very slowly in time. This is good, because you're going to charge your Zap&Go more often than a normal Power bank.

Capacity drop in time - normal LiIon batteries drop capacity in time, sooner or later, and after a few years the power bank becomes useless. In time they hold less and less charge. Supercaps have lower effect, they can drop 10% for several years. I personally have several second hand supercaps, and they all work flawlessly.

Temperature tolerance - Supercapacitors are not affected much between +60 and -20 degrees Celsius. Unlike other power banks where batteries lose capacity and/or discharge when it is too hot or cold

Deep discharge tolerance - Supercapacitors have no problems if you discharge them even to 0 volts. Rechargeable batteries, however, can reach a "point of no return"  - a voltage so low, that the battery cannot be charged/used again. Usually power banks have protection for that, but if you leave your power bank discharged on the shelf for several months, it can die.

Charging the phone - Zap&Go or any other charger does not affect your phone charging speed. The electronics in the phone control the charge, no matter the power bank and/or adapter! Yes sometimes phones/tablets can recognize fast or normal charger, but Zap&Go is able to deliver the highest speed, because it is discharging the capacitor, not a battery (to charge your phone), thus charging/discharging power can be high.

Self-discharge - self-discharge is the effect of discharging a charged battery just by staying on the shelf. Usually supercaps self-discarge for several days only, while some batteries can hold for a year. In this case the manufacturer states 20% loss of power for 72 hours, which is pretty good!
https://www.indiegogo.com/projects/zap-go-first-graphene-supercapacitor-charger

Price - the price is very high! End of story! Probably it is normal for something so new on the market. I pre-ordered mine for 99$ from Indiegogo. I am also sure that the price will drop in time.

Capacity - capacity of the Zap&Go is low. Although it is enough for charging most phones on the market. Probably in the future, they will have bigger capacitors. I wish them most of success!

Please bear in mind that the information above might be incorrect. I do not represent the manufacturer, and just quote my own knowledge.

I am sorry for writing this blog so late. Indiegogo campaign finished, and you can preorder the device now for 150$ , instead of 99$. The campaign was more than successful - 382% ($30,000 asked, $114,546 received)
I hope next year I will have my device, and will be able to write a review. I am very excited about this new technology.The USB port can be used also for a big variety of applications.

Links:
Indiegogo campaign: http://www.indiegogo.com/projects/zap-go-first-graphene-supercapacitor-charger/x/5047817
Zap&Go web site: http://www.zapandgocharger.com/
Vimeo: http://vimeo.com/zapandgo


2014-09-17

Folder name with a space in the end

Problem:
One or two times when I downloaded a torrent, it creates a folder with a blank space in the end in its name. At first I thought it is some kind of mistake from the creator of the torrent, but now I think it is done on purpose.
This folder reacts very strange, you cannot rename or delete it. In my last case, I could enter inside, but open only files with short names, without blanks.

Cause:
The reason for this problem is that the torrent program creates an invalid NTFS entry, following the information in the torrent file. Probably it won't be a big problem on Linux ext3/4.

Solution:
I found some solutions over the Internet. Many people have fought this.

-=Here is how to delete it:=-
http://stackoverflow.com/questions/21072767/windows-7-cant-delete-a-folder-with-a-trailing-space

rd "\\?\C:\holds bad subdir\20120530-04 "


-=Here is how to rename it:=-
http://superuser.com/questions/565334/rename-delete-windows-x64-folder-with-leading-and-trailing-space

rename "\\?\c:\PATH HERE\[ ]1[ ]" "NEW FILE NAME"
or
rename "\\?\c:\PATH HERE\ 1 " "NEW FILE NAME"


-=Some more information from Microsoft (6):=-
https://support.microsoft.com/kb/320081


-=Some more information from ME:=-
I wanted just to rename it, so I can access my files. I used CMD and in the folder one level up the bad one I used the following command:

dir /x

...which gives the 8.3 compatible aliases of the folder names like this:

Now you can just use the rename command, but instead of full directory name - put the alias, like
rename linksf~1 newname

Cheers!

2014-07-18

Dynamo Torch Upgrade with LED

      This is a very old project back in 2005, when LEDs were not so wide spread. I decided to transform a standard dynamo torch, and replace the bulb with LEDs. My idea was that since the LEDs need less energy for bright light, the torch will give more light with less pushing.
I found the idea and the schematics on the Internet, but now I am unable to find the web site, although I searched a lot. Perhaps it does not exist any more.

Instead of 4 rectifying diodes, I use only 2 diodes and 2 capacitors, and this schematic doubles the output voltage, which is very useful for the LEDs. Schottky diodes are used because their voltage drop is very small.

Here are some old pictures, unfortunately I don't have many:


Soldering all 5 white LEDs (they were only 5Cd) on a cardboard circle. Now I have even 30Cd.

Before that I glued one side with aluminum foil, to reflect some light.

Two capacitors are a part of the voltage doubler, the third one is just for stabilizing the voltage a little bit. They are 2200 micro F, 16V.







I used 2 very small metal plates to solder and extend the thin cables that come out of the dynamo, because if you operate a lot with them, you can easily damage them.

Here is the schematic:


Vac0 is the dynamo.
It is possible to omit C2. In that case the LEDs will light up faster, but they will also dim faster!

Regards


2014-04-05

Blue screen with nvlddmkm.sys after Windows update Nvidia drivers to 335.23

Problem
My Windows 7 (32bit) update has recently put new drivers for Nvidia (335.23). After restarting the computer nvlddmkm.sys error/blue screen/kernel dump appears and it restarts again. "Shutting down" message appears.
My video card is Nvidia GT 220.

Reason
As far as I can see this new driver 335.23 cannot work with PAE mode enabled. I use PAE mode on my windows machine, to be able to work with all available 4GB RAM with my 32bit Windows.


Solution
I downloaded the drivers from Nvidia, and made a clean install, but it did not work again :(
Newer driver is not yet available :(

Solution N1: Rollback to the old driver. (According to Nvidia documents using Device Manager to rollback driver is not a good idea - see My solution)
Solution N2: Boot without PAE (if you can).

My solution: Downgrade to version 332.21. Just download it from NVIDIA web site, and choose advanced setup, with check "Perform clean install". Of course in SAFE MODE. You are not able to boot anyway. Here are some screens:






---------------------------
Update 05.01.2017
I installed 64-bit Windows 7, and won't follow this issue any more


---------------------------
Update 23.04.2016
Driver 341.95 - does NOT work!

---------------------------
Update 09.12.2015
Driver 341.81 - does NOT work!
Driver 341.92 - does NOT work!

---------------------------
Update 07.03.2015
Driver 341.44 - does NOT work!
Scrambled. I am surprised that there is a new driver!

---------------------------
Update 20.09.2014
The newly released driver 344.11 supports only graphic cards Series 400 and above. Does that mean Nvidia cut-off support for the older models? Unfortunately yes - http://nvidia.custhelp.com/app/answers/detail/a_id/3473
So in my case I have to stay with the stable driver or Install Windows 7 64bit.

---------------------------
Update 30.07.2014
Driver 340.52 - does NOT work!
Same as 337.88.

---------------------------
Update 01.07.2014
Driver 340.43 (beta) - does NOT work!
Same as 337.88.

---------------------------
Update 27.05.2014
Driver 337.88 - does NOT work!
It crashed in blue screen during installation, while trying to restore the resolution. I tried to run the installation again and it finished. But after the reboot it tried again to switch to native resolution, artefacts on screen appear, crashed again with BSOD. Works without PAE.Going back to 332.21, my precious...

---------------------------
Update 21.05.2014
I recieved an answer from Nvidia today. They were able to recreate the issue, but as I expected, developers refuse to work on that issue, because it is due to kernel patch, NOT supported by Microsoft. However they are working on a similar issue on Windows Server 2003, where PAE is enabled and supported by Microsoft. They hope that it will resolve my issue too. I will wait, test and post results here :)

---------------------------
Update 29.04.2014
Several weeks ago I contacted Nvidia with this issue. During this time they asked for a lot, a lot of information, which I provided. They were able to locate the issue, and developers are working on it. I will keep you informed, as they keep me informed!
Very special thanks to Nvidia Support Team and nameley - Ray!


Further notices, first tries to fix it:
1. The famous youtube video https://www.youtube.com/watch?v=YrOKlh9fC9g
made the problem worse - Windows loops on "Shutting down" screen, and does not restart or issue kernel dump.
2. On 07.Apr.2014 , version 337.50 beta was released - did NOT solve the problem.
3. Downgraded to version 334.89 - did NOT solve the problem

2014-02-09

Manual for General Electric CE21886GE9-A

General Electric CE21886GE9-A is sometimes reffered as Thomson Telecom CE21886GE9-A.

I have this phone and I had really hard time finding that manual on the internet.
Here is how it looks like:




2014-01-17

Experiments with supercaps - part 2


/part 1/

Self Discharge

One of the biggest problems of the supercapacitors is their self discharge rate. I charged one of them and measured it's changes for a couple of days. The capacitors is D-size SAMWHA Green-Cap 2.7V 500F.
Here are the results:


VoltageDate/TimeJoules%charged
2.4228.12.2013 18:00146480.3
2.3428.12.2013 19:00136975.1
2.2228.12.2013 22:00123267.6
2.0429.12.2013 09:00104057.1
1.9929.12.2013 15:0099054.3
1.9629.12.2013 18:0096052.7
1.8430.12.2013 18:0084646.4
1.6602.01.2014 17:0068937.8
1.5605.01.2014 10:0060833.4
1.4708.01.2014 22:0054029.6
1.3912.01.2014 13:4248326.5



You can see that @2.7V the capacitor is charged @100%. I managed to charge it only to 80%. The last 20% are the slowest :). In the beginning the voltage drop is very significant! After ~1.8V the graphics are more linear. We lost half of the charge after only 2 days! 
So for 2 weeks we drop from 80% - 26%.
I may conclude that, the supercapacitors need something to keep the charge. Otherwise it is lost.
I don't have any Li-Ion supercapacitors for test. They should have low self discharge.

The capacitor:




-=IMPORTANT UPDATE=-
Now! I expected that, but take a closer look to these two capacitors:



Now to tell you the facts:
- 1 & 2 look absolutely the same, even the blue color, markings, numbers, everything is the same except the pins
- 1 & 2 price was the same

 Capacitor 1 facts:
- I ordered it few days ago from another online shop
- It looks absolutely new
- It has 4 pins (no documentation, but as far as I know the 2 extra pins are just to keep it stable on the electronics board)
- It charged for almost the same time as number 2, which means the capacity should be the same
- HOWEVER, the discharge time is drasticaly low! It drops to 1 Volt for less than 24h. I have 2 of them and I tested both of them. I recently noticed people complaining about that on some online shops forums.



Capacitor 2 facts:
- The first that I ordered
- It looks worn-out (that was mentioned on the shop's web site)
- It has 2 pins
- and now I remember it was written "low leakage" in the offer, that is the capacitor that I measured with the graphic above. I thought discharging time is bad, but it seems it could be worse :)


SO
My advice is to look for "low leakage" phrase. You cannot be 100% sure. I think the number of pins does not matter and very often you recieve something different from the picture on the online shop (in my case it was with 2 pins, but I received with 4 . upgrade!? :) )

I will definetely order more of the first type, however the web site moves from domain to domain. I hope they don't have legal problems. That is why I do not mention links.