Test Komponen Elektronik

untuk melakukan test komponen, sebaiknya gunakan multimeter analog.Semua pengetesan berikut menggunakan ohm meter.perlu diketahui, pada ohm meter analog, probe positif (merah) mempunyai porensial yg lebih rendah daripada probe negatif (hitam).
a. ResistorCukup dengan mencocokan nilai pada gelang dg nilai terukur. jika cukup mendekati, maka komponen tsb masih bagus.
b. KapasitorKapasitor yg bisa dites dg multimeter analog biasanya adalah C dg nilai > 100nF. tempelkan probe pada kedua kaki komponen, sambil melihat jarum penunjuk. begitu kaki ditempelkan, maka jarum akan menyimpang sesaat dan kemudian kembali ke posisi paling kiri. semakin besar nilai C, maka pergerakan jarum semakin lambat.
Kelamhannya, kita tidak dapat tahu nilai pasti C tsb. untuk C dg nilai lebih kecil, maka jarum tidak menyimpang. jika menyimpang berarti C tsb short.
c. Dioda tempelkan probe merah pada kaki anoda dan hitam pada katoda, jarum tidak menyimpang.tempelkan probe hitam pada kaki anoda dan merah pada katoda, jarum menyimpang kurang lebih 50%.
d. Transistor silahkan dilanjutkan sediri.... (masih bingung)

kalau untuk reparasi biasanya ada hal-hal yg sepele yg bisa dilakukan,misalnya resistor --> biasanya rusaknya pada fisik (cracking and charrng), yaitu ketika arus yg gede lewat jadinya kepanasan akibatnya resistansi meningkat dan resistor menjadi "open".
yg keduanya charring atau discolouring, maka resistor yg warnanya sudah pudar bisa diganti, karena biasanya kalau di cek dengan ohmmeter tetep bagus tetapi akan mengalami breakdown (open) ketika diberi Tegangan (under voltage in the circuit).
ohmmeter ini merupakan alat yg penting dalam servise elektronika karena bisa digunakan untuk mengukur kontinuitas dari komponen, komponen yg punya kontinuitas punya resistance hampir NOL, sedang yg tidak punya contonuity having infinite resistance.
misalnya mengecek FUSE maka FUSE yg baik harusnya akan terbaca 0 OHM, tapi Open (blown) FUSE akan mempunyai Infinite resistance.
untuk capacitor ada beberapa cara
1. mengukur tahanan (resistance measurement)
2. mengecek Capacitance (capacitance checker)
3. Spark Test
4. Bridging
5. substitution=untuk transistor ada 3 basic pengukuran E gain --> common collector harus low, yg lainnya high I gain --> common base harus Low, yg lainnya high Input Z --> Cbase (low), C-emitter (moderate), C-Colloector (High)Ouput Z --> Common Collector harus Low yg lain HighPower Gain --> C base (moderate), C emitter (high), C collector (moderate
selain mengecek resitansi dengan ohm meter ada beberapa teknik yg lain
1. pengukuran Tegangan
2. Heating and or freezing
3. Signal Tracing
4. Substitusion
5. Transistor Cut off
keterangannya lain kali ya Smilemungkin sulit dipahami karena masih menggunakan istilah2 anak kuliahan, karena ini sebenarnya bahan kuliah untuk anak-anak Diploma "Electronics Troubleshooting", karena keahlian di diploma ditekankan di troubleshooting, tidak seperti S1 yg Design and Analysis.lebih lengkapnya ada di buku acuan yg saya pake judulnya sama karangan Daniel R. Tomal Neal S. Widmer (McGraw Hill)disitu ada lengkap tentang cara pengukuran komponen dari resistor sampai IC dan teknik-teknik troubleshooting.

ETHERNET CABLE: COLOR-CODE STANDARDS

The information listed here is to assist Network Administrators in the color coding of Ethernet cables. Please be aware that modifying Ethernet cables improperly may cause loss of network connectivity. Use this information at your own risk, and insure all connectors and cables are modified in accordance with standards. The Internet Centre and its affiliates cannot be held liable for the use of this information in whole or in part.

T-568A Straight-Through Ethernet Cable

The TIA/EIA 568-A standard which was ratified in 1995, was replaced by the TIA/EIA 568-B standard in 2002 and has been updated since. Both standards define the T-568A and T-568B pin-outs for using Unshielded Twisted Pair cable and RJ-45 connectors for Ethernet connectivity. The standards and pin-out specification appear to be related and interchangeable, but are not the same and should not be used interchangeably.

T-568B Straight-Through Ethernet Cable

Both the T-568A and the T-568B standard Straight-Through cables are used most often as patch cords for your Ethernet connections. If you require a cable to connect two Ethernet devices directly together without a hub or when you connect two hubs together, you will need to use a Crossover cable instead.

RJ-45 Crossover Ethernet Cable

A good way of remembering how to wire a Crossover Ethernet cable is to wire one end using the T-568A standard and the other end using the T-568B standard. Another way of remembering the color coding is to simply switch the Green set of wires in place with the Orange set of wires. Specifically, switch the solid Green (G) with the solid Orange, and switch the green/white with the orange/white.

Ethernet Cable Instructions:

1. Pull the cable off the reel to the desired length and cut. If you are pulling cables through holes, its easier to attach the RJ-45 plugs after the cable is pulled. The total length of wire segments between a PC and a hub or between two PC's cannot exceed 100 Meters (328 feet) for 100BASE-TX and 300 Meters for 10BASE-T.

2. Start on one end and strip the cable jacket off (about 1") using a stripper or a knife. Be extra careful not to nick thewires, otherwise you will need to start over.

3. Spread, untwist the pairs, and arrange the wires in the order of the desired cable end. Flatten the end between your thumb and forefinger. Trim the ends of the wires so they are even with one another, leaving only 1/2" in wire length. If it is longer than 1/2" it will be out-of-spec and susceptible to crosstalk. Flatten and insure there are no spaces between wires.

4. Hold the RJ-45 plug with the clip facing down or away from you. Push the wires firmly into the plug. Inspect each wire is flat even at the front of the plug. Check the order of the wires. Double check again. Check that the jacket is fitted right against the stop of the plug. Carefully hold the wire and firmly crimp the RJ-45 with the crimper.

5. Check the color orientation, check that the crimped connection is not about to come apart, and check to see if the wires are flat against the front of the plug. If even one of these are incorrect, you will have to start over. Test the Ethernet cable.

Ethernet Cable Tips:

• A straight-thru cable has identical ends.
• A crossover cable has different ends.
• A straight-thru is used as a patch cord in Ethernet connections.
• A crossover is used to connect two Ethernet devices without a hub or for connecting two hubs.
• A crossover has one end with the Orange set of wires switched with the Green set.
• Odd numbered pins are always striped, even numbered pins are always solid colored.
• Looking at the RJ-45 with the clip facing away from you, Brown is always on the right, and pin 1 is on the left.
• No more than 1/2" of the Ethernet cable should be untwisted otherwise it will be susceptible to crosstalk.
• Do not deform, do not bend, do not stretch, do not staple, do not run parallel with power cables, and do not run Ethernet cables near noise inducing components.

Basic Theory:

By looking at a T-568A UTP Ethernet straight-thru cable and an Ethernet crossover cable with a T-568B end, we see that the TX (transmitter) pins are connected to the corresponding RX (receiver) pins, plus to plus and minus to minus. You can also see that both the blue and brown wire pairs on pins 4, 5, 7, and 8 are not used in either standard. What you may not realize is that, these same pins 4, 5, 7, and 8 are not used or required in 100BASE-TX as well. So why bother using these wires, well for one thing its simply easier to make a connection with all the wires grouped together. Otherwise you'll be spending time trying to fit those tiny little wires into each of the corresponding holes in the RJ-45 connector.

TRY SECOND POSTING

Ini posting kedua untuk melatih cara meng-upload gambar dari picasaweb album.

Note : telah login pada blogger dan siap membuat post baru.

Cara-caranya sbb:

1. sign-in ke picasa web album dengan account gmail disini.

(menggunakan i.e>5.0 ,terdapat permasalahan bila login dengan firefox)
tapi selanjutnya kok ga masalah ya?????

2. klik pada "My Photos" --> Upload photos.

3. isi form atau upload pd existing album. (bila pertama kali menggunakan picasa web akan ada script yang akan diminta untuk diinstall pada i.e), lanjutkan wizard-nya.

4. bila photo telah ter-upload, klik pada foto yang akan dimasukkan pada blog.

5. klik pada "Embed in Blog/MySpace" lalu copy-paste pada posting blog yang sedang dibuat.

6. bila keseluruhan HTML di copy-paste di posting yg sedang dibuat (pada "Edit Html" tab)maka hasilnya akan seperti dibawah ini.

From PicturesBlog

7. Bila checkbox "Hide Album link" dipilih hasilnya seperti dibawah ini:

8. tetapi bila kita cuma mengambil link pada fotonya saja.

http://picasaweb.google.com/planet80s/PicturesBlog/photo#5024329341223292242">

maka akan menghasilkan seperti diatas.

9. Bila ada kesalahan pejelasan diatas " please use your head" n comment this post.

FIRST POSTING

May be i prefer to use bahasa rather than english, it's to avoid from spell and grammar mistake.
But sometimes i will use english.

Blog ini di peruntukkan untuk mendokumentasikan pikiran saya agar hal-hal yang selama ini saya pelajari tidak hilang begitu saja, dan juga untuk memacu untuk terus menambah isi dari otak saya yang tak pernah penuh ini.
Diharapkan masukan dari teman2 tentang posting2 yang saya publish.
"It's not human if never fall (wrong)"

vasumitra

thx