Fibre to Fibre Connections

11:10 PM at 11:10 PM

Introduction:

Two fibre may be joined either b splicing, which is a permanent join, or by a connection which is permits repeat coupling and uncoupling. Permanent splices have applications in long distance communication links and in the construction of integrated fibre sensor systems. Connectors are used to couple fibre transmitter and receiver modules, and devices in optical communication system.

Both types of join have the following requirements:

1) The fibre end faces must optically flat and perpendicular to the fibre axis.

2) The two fibres to be joined must be perfectly aligned.

3) The joint needs to be mechanically strong and the procedure itself must be simple and easily carried out in the field.

Experiments:

Part I, Mechanical Splice – “Ultra Splice”

This technique archive insertion losses of ~0.01dB and the mechanical strength of the join is ~60% of the original fibre strength. Other splicing methods depend on precision aligned groove techniques. The fibres to be joined are inserted into the groove and held in place either by an index-matching epoxy or by purely mechanical mean. The advantage of these methods is that they are quick and simple procedures and untrained operators can routinely achieve losses of ~0.1-0.3dB.


The image “http://www.tecratools.com/pages/tecalert/graphics/mechanical_splice.jpg” cannot be displayed, because it contains errors.

Mechanical Splice

In the experiment, we have power in 3.00mW and power out 2.85mW, then the lost in dB is:

Loss in dB = -10 x log(2.8/3.0) = 0.22dB

Part II, Fusion Splice

Thermal fusion is the highest quality splice. In this process the fibres are aligned with precision stages under microprocessor control. A plasma touch or an electric are is the passed across the junction of the fibres fusing them together. It has typical losses about 0.1dB.


The image “http://www.tecratools.com/pages/tecalert/graphics/fusion_splice.jpg” cannot be displayed, because it contains errors.

The image “http://www.alsys.ro/images/produse/s_s175.jpg” cannot be displayed, because it contains errors.

Fitel Fusion Splicer

In the experiment, we had power in 3.00mW and power out 2.90mW, the loss in dB :

Loss in dB = -10 x log(2.90/3.00) = 0.15dB

Conclusion:

In this experiment we were introduced two types of splicing, the mechanical splicing and thermal fusion splicing. The data we got during the experiment is close to or in the range of the typical value. Fusion splicing produces lower loss and less back reflection than mechanical splicing, because the resulting fusion splice points are almost seamless.


Picture Reference:

http://www.tecratools.com/pages/tecalert/splicing_guide.html
http://www.alsys.ro/en/networking/networking.php

Hide / Unhide Extended ROM on Dopod D810

9:30 PM at 9:30 PM

HIDDEN:

HKEY_LOCAL_MACHINE\System\StorageManager\AutoLoad\EXT_FLASHDRV
"Bootphase"=dword:00000001

HKEY_LOCAL_MACHINE\System\StorageManager\Profiles\EXT_FLASHDRV
"MountHidden"=dword:00000001

Enable the GPS icon in setting on dopod D810

6:33 PM at 6:33 PM

GPS icon in settings use regedit, go to HKEY_LOCAL_MASCHINE\ControlPanel\GPS Settings ,

1.Add a DWORD called "Group" and give it the value of "2" (dec)
2,keep the Hide key but change the value to 0 ,
3,Soft reset

you will see the icon in settings

Enable the GPS service on dopod D810

6:28 PM at 6:28 PM

By default, D810 doesn't has GPS service enabled, but it has GPS chip set, to enable the GPS just need upgrade the firmware, here is :

http://www.dopodasia.com/download/RUU_Trinity_DOPODASIA_WWE_1.23.707.6_6275_1.35.00.11_108_Ship.zip

it's very easy in steps.

Centipede and Peron's Tree Frog

11:57 PM at 11:57 PM

I catch a centipede and a Peron's tree frog in my house today.

I found some informations about this frog:

The image “http://upload.wikimedia.org/wikipedia/en/thumb/e/e4/L_peronii.jpg/240px-L_peronii.jpg” cannot be displayed, because it contains errors.

See more on wikipedia : Peron's Tree Frog

Add volume control to AKG K26P

1:27 PM at 1:27 PM

I had my AKG K26P about 1.5 month ago, spend me $75AUD in Sydney HiFi shop, in the same time, there also has AKG K27i, it is a ipod version headphone, white color and with volume control, but the price is $129AUD ! Here is the details of these two headphone :

K 26 P / K 27 i

Type K 26 P: dynamic, closed-back
K 27 i: dynamic, closed-back
Efficiency K 26 P: 125 dB SPL/V
K 27 i : 126 dB SPL/V
Frequency range K 26 P: 12 Hz to 28 kHz
K 27 i : 11 Hz to 28.5 kHz
Rated impedance 32 ohms
THD <1%
Cable 1.5 m (5 ft.)
Connector Stereo mini plug
Net weight (without cable) Approx. 2.6 oz.
Special features K 26 P :
Folding mechanism
K 27 i :
Folding mechanism
Integrated precision volume control


Photo : (Left : K26P, Right : K27i)
The image “http://www.nusystems.co.uk/images/products/medium/AKG.K26P.2597.jpg” cannot be displayed, because it contains errors. http://www.musik-service.de/images/ProduX/395752743j00.jpg
Firstly, I had two wires of Sennheiser MX500, It has a volume control! I was broke the earphone, but wire is like new. The wire is asymmetrical, so cut the longer side as same as the shorter side.

Then, open the K26P, solder off the original wires, and solder the MX500 wire on.

Here has some photos of the works:

K608i 拆机照

9:16 AM at 9:16 AM

因为前几天 Motorola V3x 大减价,所以忍不住要让手机更新换代了,一是因为手机这东西一般用过一年多就会出现些小毛病,趁此还不如在出毛病前处理掉,二是因为V3x是我的梦机。为了更一步减低对V3x的花费,我就要把K608i在ebay上卖掉,卖掉之前特拆机留照以作纪念。