Telah hadir buku / Tutorial yang anda tunggu-tunggu.

“ Exploring of Injection Moulding Machine “

Buku ini saya susun berdasarkan pengalaman sebagai teknisi mesin Injeksi selama 16 tahun. Kurun waktu tersebut bukanlah waktu yang singkat untuk dapat memahami dan menelanjangi teknologi mesin Injection. Dalam perjalanan tersebut saya sudah banyak disiksa dan kenyang makan asam garam mesin plastik dimana karir saya sebagai teknisi dimulai dengan menangani jenis mesin control relay mekanik sampai control microcomputer.
Tujuan mempublikasikan tutorial ini untuk membantu bagi anda yang baru terjun didunia cetak mencetak produk plastik dengan media mesin Injection disamping sebagai operator, setter atau teknisi lapangan yang baru terjun lantas bingung mencari informasi mesin tersebut.
Sebenarnya banyak informasi yang dapat anda peroleh via Internet namun terpotong-potong dan kurang terdefinisi bila dibandingkan dengan mesin yang anda hadapi. Tak heran karena seperti dunia elektronik, mesin Injection mengalami perkembangan pesat setiap tahunnya. Untuk itulah buku/tutorial ini saya susun secara terstruktur sehingga anda dapat menguasai teknologi mesin Injection secara cepat dan tepat.
Bagaimanakah cara anda mendapatkan buku ini ?. gampang berikut informasinya :

Judul buku : Exploring of Injection Moulding Machine.
Pengarang : Yonni Muhazir.
Bahasa pengantar : Bahasa Indonesia.
Tebal buku : 110 Halaman, Hard Cover.
Statistik buku :21.601 words, Arrial Narrow 12 Point, 1 space.
Kertas : A4, Sidu 70 grams, Cannon printing iP 1980.
Harga : Rp 200.000,-
Dalam kota bebas ongkos kirim.
Dalam propinsi Jatim dikenakan bea kirim Rp 15.000,-
Luar propinsi Jatim dikenakan bea kirim Rp 30.000,-

Cara pemesanan :
Via wessel pos alamatkan ke : Jalan Laksda Adi Sucipto gang 8 no 7 Malang 65125. Buku akan dikirim via paket pos 3 hari setelah uang dicairkan. Kenapa pakai cara tradisional ?. Cara lama lebih disukai karena relatif aman daripada open via transfer bank yang banyak resiko. Bila anda harus melakukan transfer, dapat via BCA yang terlebih dahulu telepon saya kemudian ikuti wizardnya.
Bila ada masalah dalam pengiriman atau lain hal, dapat kontak melalui HP XL 081 803 842 554 a/n : Yonni Muhazir. Atau email ke Yonni_1967@yahoo.co.id .

Mahal amat harga bukunya ?……itu mungkin komentar dalam hati anda………., ..…Sekedar informasi, berikut kalkulasinya :

Beaya cetak 110 halaman x 1000 = Rp 110.000,-
Beaya Hard cover = Rp 30.000,-
Lain lain Rp 15.000,- (beaya transportasi mondar-mandir)

Jadi saya hanya untung tak lebih dari Rp 60.000,- perbukunya dan itu sebagai kompensasi saya sebagai upah lembur mengetik dan lembur ngeprint dan yang terutama harga Informasi yang berharga demi untuk anda. Harga buku sebanding dengan kerja keras saya melekan tiap malam ngetik dan peluh keringat saya mengumpulkan informasi. Anda tidak akan kecewa deh, dari pada anda banyak menghabiskan uang di Internet surfing kesana-kemari. Untuk bahan pertimbangan ( seperti membeli kucing dalam sarung eh..karung dan membuat anda kecewa nanti ), sebelum memesan buku silakan mengintip isinya disini :

Harga dapat berubah-ubah sesuai harga kertas, harga tinta, dan perubahan lain hal. Jadi buruan pesan sekarang juga. Tunggu penerbitan jilid kedua dan ketiga yang tentunya lebih seru dan hot. Dijamin.

Jilid 2 ( Coming soon ) : Hidraulica of Injection Moulding Machine.
Jilid 3 ( Coming soon ) : Getting Start with Injection Moulding Machine.

Maaf tidak melayani pengiriman dalam bentuk soft copy. Semoga bermanfaat bagi semua. Amin……….

Berikut listing program bascom AVR untuk injection moulding machine yang telah saya buat.
Ternyata enak ya pakai compiler Basic ini? Memprogram jadi menyenangkan dan semakin ingin lebih mendalam dibanding bahasa ‘C’ atau Asembler yang mbulet.
silakan coba!…$$$$$

Berikut listingnya :

‘———Program aplikasi sekuensi injection moulding machine——’
‘Dibuat oleh : Yonni Muhazir
‘Nim : 0510450391/E
‘Fakultas teknik / elektronika
‘Uwiga Malang, January 2009
‘———————————————————————’

$regfile = “m8535.dat”
$crystal = 4000000
$baud = 9600

Dim Automatis As Bit , Y1 As Bit , Ls_close As Bit ‘Y1 adalah coil mold closing– output portb.0/ y1 ‘
Config Porta = Input
Set Porta.0
Port A.0 Alias Automatis
Port A.1 Alias Ls_close ‘automatis tombol start automatis–input porta.0′
Config Portb = Output
Set Portb.0
Portb.0 Alias Y1

Do

If Automatis = 1 Then
Y1 = 1
Else
If Ls_close = 1 Then ‘ls_close adalah stop closing–input port : input porta.1′
Y1 = 0
End If
End If

Dim Ls_clamping As Bit , Y2 As Bit ‘y2 adalah yoke clamping–portb.1′
Set Porta.2
Porta.2 Alias Ls_clamping ‘ls_clamping ;input porta.2
Set Portb.1 Alias Y2
Port A.2 Alias Ls_clamping
If Ls_clamping = 1 Then
Y2 = 1
Else
Waitms 100
Print “timer clamping” ‘timer generation clamping
End If

Dim , Y3 As Bit , Ls_iu_stop As Bit ‘y3=yoke IU maju–output portb.2′,
Set Porta.3
Porta.3 Alias Ls_iu_stop ‘Ls IU maju stop– input porta.3
Set Portb.2
Portb.2 Alias Y3
If Y2 = 0 Then
Y3 = 1
Else
If Ls_iu_stop = 1 Then
Y3 = 0
End If
End If

Dim Y4 As Bit , Ls_inj_end As Bit
Set Porta.4 ‘ls_inj_end = input porta.4,
Porta.4 Alias Ls_inj_end ‘y4=yoke injection-output portb.4′
Set Portb.4
Portb.4 Alias Injection Yoke
If Y3 = 0 Then
Y4 = 1
Else
Waitms 200 ‘timer injection berjalan 500ms’
Print “timer injection on”
If Ls_inj_end = 1 Then
Y4 = 0
End If
End If

Dim Plasticizing As Bit , Ls_plast As Bit , Decomp As Bit , Ls_decomp As Bit , Cooling As Bit
Set Portb.5
Portb.5 Alias Plasticizing ‘y5 =plasticizing – output portb.5′
Set Porta.5
Porta.5 Alias Ls_plast ‘ ls_stop plasticizing – input porta.5′
Set Portb.6
Portb.6 Alias Decomp ‘ y6-decompression : output portb.6
Set Porta.6
Porta.6 Alias Ls_decomp ‘ ls decompression stop ; input port a.6

If Y4 = 0 Then
Plasticizing = 1 ‘ saat plasticizing,
Else
If Ls_plast = 1 Then ‘ plasticizing berhenti
Plasticizing = 0
Else
If Ls_plast = 1 Then

Else
If Plasticizing = 0 Then
Decomp = 1

Else
If Ls_plast = 1 Then ‘mundurkan decompresi’
Decomp = 0

End
End If
End If
End If
End If
End If

Waitms 300 ‘ cooling time berjalan’
Print ” cooling time runing”

Dim Iu_ret As Bit , Ls_iu_ret_stop As Bit , Mold_opn As Bit , Ls_opn_stp As Bit

Set Portb.7
Portb.7 Alias Iu_ret ‘yoke injection unit mundur output portb.7′
Set Porta.7
Porta.7 Alias Ls_iu_ret_stop ‘ls IU stop mundur input porta.7′

Config Portc = Output ‘konfigurasi pin port c sebagai output’
Config Portd = Input ‘konfigurasi portd sebagai input’

Set Portc.0
Portc.0 Alias Mold_opn ‘yoke mold open–output portc.0′
Set Portd.0
Portd.0 Alias Ls_opn_stop ‘ls_open stop mold–input portd.0

If Decomp = 0 Then
Iu_ret = 1 ‘injection unit mundur
Else
If Ls_iu_ret_stop = 1 Then
Mold_opn = 1 ‘mould membuka penuh sampai ls stop tertekan’
Else
If Ls_opn_stp = 1 Then
Mold_opn = 0
End If
End If
End If

Dim Eject_maju As Bit , Eject_mundur As Bit , Ls_eject_maju As Bit , Ls_eject_mundur As Bit
Dim Multi_eject As Integer
Set Portc.1
Portc.1 Alias Eject_maju ‘portc.1 = eject maju – output portc.1′
Set Portd.1
Portd.1 Alias Ls_eject_maju ‘ls_eject maju = input portd.1
Set Portc.2
Portc.2 Alias Eject_mundur ‘ yoke eject_mundur = output_eject_mundur = output portd.2
Set Portd.2
Portd.2 Alias Ls_eject_mundur ‘ ls_stop_eject_mundur = input portd.2

For Multi_eject = 147 To 157 Step 3 ‘perintah multi eject/maju-mundur 3 step’

If Ls_opn_stp = 1 Then
Eject_maju = 1 ‘ejector maju sampai ls stop,
Else
If Ls_eject_maju = 1 Then
Eject_maju = 0
Else
If Ls_eject_maju = 1 Then
Eject_mundur = 1 ‘ejector mundur’
Else
If Ls_eject_mundur = 1 Then
Eject_mundur = 0
End If
End If
End If
End If
Next
‘
Print “Pause_time”
Waitms 340

Loop ‘perintah kembali ke program awal—begitu seterusnya’

End ‘end program’———Program aplikasi sekuensi injection moulding machine——’
‘Dibuat oleh : Yonni Muhazir
‘Nim : 0510450391/E
‘Fakultas teknik / elektronika
‘Uwiga January Malang 2009
‘———————————————————————’

$regfile = “m8535.dat”
$crystal = 4000000
$baud = 9600

Dim Automatis As Bit , Y1 As Bit , Ls_close As Bit ‘Y1 adalah coil mold closing– output portb.0/ y1 ‘
Config Porta = Input
Set Porta.0
Port A.0 Alias Automatis
Port A.1 Alias Ls_close ‘automatis tombol start automatis–input porta.0′
Config Portb = Output
Set Portb.0
Portb.0 Alias Y1
If Automatis = 1 Then
Y1 = 1
Else
If Ls_close = 1 Then ‘ls_close adalah stop closing–input port : input porta.1′
Y1 = 0
End If
End If

Dim Ls_clamping As Bit , Y2 As Bit ‘y2 adalah yoke clamping–portb.1′
Set Porta.2
Porta.2 Alias Ls_clamping ‘ls_clamping ;input porta.2
Set Portb.1 Alias Y2
Port A.2 Alias Ls_clamping
If Ls_clamping = 1 Then
Y2 = 1
Else
Waitms 100
Print “timer clamping” ‘timer generation clamping
End If

Dim , Y3 As Bit , Ls_iu_stop As Bit ‘y3=yoke IU maju–output portb.2′,
Set Porta.3
Porta.3 Alias Ls_iu_stop ‘Ls IU maju stop– input porta.3
Set Portb.2
Portb.2 Alias Y3
If Y2 = 0 Then
Y3 = 1
Else
If Ls_iu_stop = 1 Then
Y3 = 0
End If
End If

Dim Y4 As Bit , Ls_inj_end As Bit
Set Porta.4 ‘ls_inj_end = input porta.4,
Porta.4 Alias Ls_inj_end ‘y4=yoke injection-output portb.4′
Set Portb.4
Portb.4 Alias Injection Yoke
If Y3 = 0 Then
Y4 = 1
Else
Waitms 200 ‘timer injection berjalan 500ms’
Print “timer injection on”
If Ls_inj_end = 1 Then
Y4 = 0
End If
End If

Dim Plasticizing As Bit , Ls_plast As Bit , Decomp As Bit , Ls_decomp As Bit , Cooling As Bit
Set Portb.5
Portb.5 Alias Plasticizing ‘y5 =plasticizing – output portb.5′
Set Porta.5
Porta.5 Alias Ls_plast ‘ ls_stop plasticizing – input porta.5′
Set Portb.6
Portb.6 Alias Decomp ‘ y6-decompression : output portb.6
Set Porta.6
Porta.6 Alias Ls_decomp ‘ ls decompression stop ; input port a.6

If Y4 = 0 Then
Plasticizing = 1 ‘ saat plasticizing,
Else
If Ls_plast = 1 Then ‘ plasticizing berhenti
Plasticizing = 0
Else
If Ls_plast = 1 Then

Else
If Plasticizing = 0 Then
Decomp = 1

Else
If Ls_plast = 1 Then ‘mundurkan decompresi’
Decomp = 0

End
End If
End If
End If
End If
End If

Waitms 300 ‘ cooling time berjalan’
Print ” cooling time runing”

Dim Iu_ret As Bit , Ls_iu_ret_stop As Bit , Mold_opn As Bit , Ls_opn_stp As Bit

Set Portb.7
Portb.7 Alias Iu_ret ‘yoke injection unit mundur output portb.7′
Set Porta.7
Porta.7 Alias Ls_iu_ret_stop ‘ls IU stop mundur input porta.7′

Config Portc = Output ‘konfigurasi pin port c sebagai output’
Config Portd = Input ‘konfigurasi portd sebagai input’

Set Portc.0
Portc.0 Alias Mold_opn ‘yoke mold open–output portc.0′
Set Portd.0
Portd.0 Alias Ls_opn_stop ‘ls_open stop mold–input portd.0

If Decomp = 0 Then
Iu_ret = 1 ‘injection unit mundur
Else
If Ls_iu_ret_stop = 1 Then
Mold_opn = 1 ‘mould membuka penuh sampai ls stop tertekan’
Else
If Ls_opn_stp = 1 Then
Mold_opn = 0
End If
End If
End If

Dim Eject_maju As Bit , Eject_mundur As Bit , Ls_eject_maju As Bit , Ls_eject_mundur As Bit

Set Portc.1
Portc.1 Alias Eject_maju ‘portc.1 = eject maju – output portc.1′
Set Portd.1
Portd.1 Alias Ls_eject_maju ‘ls_eject maju = input portd.1
Set Portc.2
Portc.2 Alias Eject_mundur ‘ yoke eject_mundur = output_eject_mundur = output portd.2
Set Portd.2
Portd.2 Alias Ls_eject_mundur ‘ ls_stop_eject_mundur = input portd.2

If Ls_opn_stp = 1 Then
Eject_maju = 1
Else
If Ls_eject_maju = 1 Then
Eject_maju = 0
Else
If Ls_eject_maju = 1 Then
Eject_mundur = 1
Else
If Ls_eject_mundur = 1 Then
Eject_mundur = 0
End If
End If
End If
End If

Print “Pause_time”
Waitms 340

Goto 20
End

End ‘end program

Silakan unduh file berikut bagi yang mendalami teknik pembangkit, sangat berguna bagi mahasiswa yang konsentrasi di mata kuliah pembangkit listrik

Please download following files for increasing a generating technique which student is very concentration in power station.

generator-tutorial

George Simon Ohm (1787-1854)

Georg Simon Ohm was a German physicist born in Erlangen, Bavaria, on March 16, 1787. As a high school teacher, Ohm started his research with the recently invented electrochemical cell, invented by Italian Count Alessandro Volta. Using equipment of his own creation, Ohm determined that the current that flows through a wire is proportional to its cross sectional area and inversely proportional to its length or Ohm’s law.

George Simon Ohm adalah seorang fisikawan jerman yang lahir di Erlangen, Bavaria pada tanggal 16-maret-1787. Dia hanyalah seorang guru SMA yang memulai risetnya saat teknik Electrochemical Cell ditemukan oleh Alessandro Volta dari Italia.

Using the results of his experiments, Georg Simon Ohm was able to define the fundamental relationship between voltage, current, and resistance. These fundamental relationships are of such great importance, that they represent the true beginning of electrical circuit analysis.

Dari hasil eksperimennya George Simon Ohm menemukan hubungan dasar antara Tegangan, Arus dan Resistansi. Hubungan dasar ini menjadi sangat penting dan menjadi cikal bakal semua acuan untuk menganalisa sirkuit listrik sampai masa kini.

Unfortunately, when Ohm published his finding in 1827, his ideas were dismissed by his colleagues. Ohm was forced to resign from his high-school teaching position and he lived in poverty and shame until he accepted a position at Nüremberg in 1833 and although this gave him the title of professor, it was still not the university post for which he had strived all his life.

Sayangnya, pada saat dia mengumumkan penemuan itu di tahun 1827, ide itu dicekal oleh para koleganya. Dengan tidak mengenal putus asa dan rasa malu George tetap mengajar di kelasnya dan hidup dalam tekanan ekonomi sampai akhirnya idenya diterima di Nuremberg pada tahun 1833 hingga mendapat gelar profesor. Yang patut diteladani walau gelarnya tinggi ia tetap bersahaja tidak sok ilmuwan dan terus berjuang sepanjang hayatnya.

Ohm the Genius! the Mozart of Electricity …

Ohm and corrosion monitoring

Ohm’s main interest was current electricity, which had recently been advanced by Alessandro Volta’s invention of the battery. Ohm made only a modest living and as a result his experimental equipment was primitive. Despite this, he made his own metal wire, producing a range of thickness and lengths of remarkable consistent quality. The nine years he spent at the Jesuit’s college, he did considerable experimental research on the nature of electric circuits. He took considerable pains to be brutally accurate with every detail of his work. In 1827, he was able to show from his experiments that there was a simple relationship between resistance, current and voltage.

Ohm’s sangat tertarik menyelidiki arus listrik setelah Alessandro Volta menemukan battery. Dalam penyelidikan itu Ohm mempergunakan alat-alat sederhana dan kuno namun dalam teknik pembuatanya ia memperhatikan kualitas secara presisi seperti kawat metal buatannya. Setelah menghabiskan pendidikannya di perguruan tinggi Jesuit’s, Ohm lebih amat sangat teliti dalam semua pekerjaannya. Pada tahun 1827 barulah ia berani mempertunjukan hubungan sederhana antara resistance, arus dan tegangan.

Ohm’s law stated that the amount of steady current through a material is directly proportional to the voltage across the material, for some fixed temperature:

Ohms menyatakan bahwa arus yang mengalir melalui suatu bahan adalah sepadan dengan tegangan yang melintasi bahan itu. Dinyatakan dalam rumus yang terkenal :

I = V/R

Ohm had discovered the distribution of electromotive force in an electrical circuit, and had established a definite relationship connecting resistance, electromotive force and current strength.

Kemudian Ohms menemukan distribusi dari gaya elektromotif dalam rangkaian listrik yang menentukan hubungan pasti terhadap rangkaian resistance, gaya electromotive dan kuat arusnya.

Ohm was afraid that the purely experimental basis of his work would undermine the importance of his discovery. He tried to state his law theoretically but his rambling mathematically proofs made him an object of ridicule. In the years that followed, Ohm lived in poverty, tutoring privately in Berlin. He would receive no credit for his findings until he was made director of the Polytechnic School of Nüremberg in 1833. In 1841, the Royal Society in London recognized the significance of his discovery and awarded him the Copley medal. The following year, they admitted him as a member. In 1849, just 5 years before his death, Ohm’s lifelong dream was realized when he was given a professorship of Experimental Physics at the University of Munich. On July 7th,1854 he passed away in Munich, at the age of 65.

Hampir-hampir ia ragu bahwa hasi teori dasarnya gugur dan menjadi bahan olok-olokan karena selama itu kemiskinan selalu menderanya hingga ia tetap mengajar secara privat di Berlin. Karena itulah hasil penemuannya tidak pernah mendapat simpati dan pengakuan sampai pada akhirnya menjadi pucuk pimpinan di sekolah polyteknik Nuremberg pada tahun 1833. Di tahun 1849, lima tahun sebelum wafat, mimpi panjangnya menjadi kenyataan saat menjadi guru besar di Experimental Physics, the University of Munich. Ohm wafat di usia 65 tahun, tepatnya 7-Juli-1854.

This belated recognition was welcome but there remains the question of why someone who today is a household name for his important contribution struggled for so long to gain acknowledgement. This may have no simple explanation but rather be the result of a number of different contributory factors. One factor may have been the inwardness of Ohm’s character while another was certainly his mathematical approach to topics which at that time were studied in his country a non-mathematical way. There was undoubtedly also personal disputes with the men in power which did Ohm no good at all. He certainly did not find favor with Johannes Schultz who was an influential figure in the ministry of education in Berlin, and with Georg Friedrich Pohl, a professor of physics in that city.

Pengakuan teori ohm terlambat namun kematiannya membekaskan pertanyaan : mengapa perjuangan panjang beliau sangat berat dan panjang untuk mendapat pengakuan setelah kematiannya, padahal penemuan (yang dianggap) sepele itu ikut ambil bagian terbesar dalam peralatan rumah tangga kita?. Ini membutuhkan penjelasan panjang dan banyak penyebab. Salah satu faktornya mungkin pembahasan teorinya dengan pendekatan matematis yang rumit sedangkan latar belakang sekolahnya dianggap tidak mendukung apa yang digagaskannya. Pada saat itu banyak orang meragukan bahwa teorinya hanya bualan semata!. Pada saat itu sayangnya ia tidak mengenal kebaikan hati orang yang berpengaruh seperti Johannes Schultz sebagai menteri pendidikan di Berlin dan Friedrich Pohl, seorang professor fisika di kotanya.

Electricity was not the only topic on which Ohm undertook research, and not the only topic in which he ended up in controversy. In 1843 he stated the fundamental principle of physiological acoustics, concerned with the way in which one hears combination tones. However the assumptions which he made in his mathematical derivation were not totally justified and this resulted in a bitter dispute with the physicist August Seebeck. He succeeded in discrediting Ohm’s hypothesis and Ohm had to acknowledge his error.

Padahal bidang kelistrikan bukanlah topic utama Ohm dalam semua risetnya dan bukanlah perjalanan kontroversi satu-satunya dalam penemuannya. Di tahun 1843 bahkan ia menyatakan prinsip dasar psikologi akustik yang menyelidiki respon pendengaran manusia terhadap kombinasi nada. Lagi-lagi dengan asumsi bahwa Ohm bukan Ilmuwan dan pakar matematika handal, ia menuai hinaan yang menyakitkan dari fisikawan August Seebeck, dalam perdebatan, Seebeck telah berhasil meruntuhkan hipotesa Ohm salah besar!. He..he…he…dia keliru besar.

Pesan dan kesan : bahwa tidak semua penemuan besar lahir dari disiplin bidang keilmuan yang sama. Perjuangan yang panjang dengan kesabaran dan disiplin tinggi dapat mencapai hasil yang bermanfaat bagi umat manusia. Jangan pernah meremehkan pendapat orang lain karena latar belakangnya atau kemiskinannya.

Salam : Yonni.

Bottom of Form

]]> http://yonni1967.wordpress.com/2008/10/05/george-simon-ohm/feed/ 0 yonni1967 ohm-poto1 http://yonni1967.wordpress.com/2008/10/02/power-amplifier-tutorial/ http://yonni1967.wordpress.com/2008/10/02/power-amplifier-tutorial/#comments Thu, 02 Oct 2008 14:19:52 +0000 yonni1967 http://yonni1967.wordpress.com/?p=164 ]]>

Understanding amplifier power ratings

(pemahaman rating power amplifier)

There are different methods for measuring the power ratings for amplifiers and speakers. And different measuring methods give different values so it is vital to understand the difference between theosedifferent power ratings to be able to make at least some comaparision between different power ratings. This article is collection of information posted to rec.audio.tech newsgroup at July 1996. The information is compiled from Usenet newsgroup rec.audio.pro articles written by Norbert Hahn, Dick Pierce and Earl K.

Ada beberapa cara berbeda untuk mengukur nilai power amplifier dan speaker. Cara pengukuran ini memberikan pandangan sangat berbeda dan penting untuk memahami perbedaan antara theosedifferent power rating yang membuat perbedaan comparision power rating. Artikel ini koleksi dari posting rec.audio.tech newsgroup pada bulan Juli 1996. Informasi di-compile dari Usenet newsgroup rec.audio.pro dan ditulis oleh Norbert Hahn, Dick pierce dan Earl K.

RMS power

(Apa sih RMS itu ?)

To make it short, an RMS power value is directly related to perceivable energy (acoustical, heat, light – or what else applies).

Arti harfiahnya ialah : RMS adalah suatu nilai tenaga (power) yang secara langsung dihubungkan dengan energi yang dapat dipahami (akustik, panas, cahaya atau sejenisnya).

“RMS” is really a rather meaningless figure, when measuring power. R.M.S. is useful for measuring the “power-producing equivalent” voltage. Thus 10 Volts RMS will produce the same power into a given impedance that 10 Volts DC would produce (onto a resistance) Any waveform of 10 V R.M.S.will produce the same power into that impedance. This is because it’s the root of the mean of all the average squared voltages to which Norbert Hahn referred in the prior post. It is if little meaning to compute the mean of squares of all the power values in a wave.

” RMS” sebenarnya suatu figur yang tidak penting saat mengukur power. R.M.S. bermanfaat untuk mengukur ” power-producing (yang sepadan)” dengan voltase. Dengan umpan 10 VOLT RMS akan menghasilkan sama ke dalam impedansi yang ditentukan dan akan menghasilkan 10 VOLT DC ( dalam resistansi) semua bentuk gelombang apapun dari 10 V R.M.S. Ini adalah musabab akar dari semua rata-rata dalam tegangan seperti yang direferensikan oleh Norbert Hahn di postingnya. Pemahaman ini lebih sedikit dibanding perhitungan mean of square ( nilai akar rata-rata) pada segala nilai dan bentuk gelombang.

RMS, when applied to power measurements, has come to mean “sine-wave power.” A 100 Watt “RMS” amplifier can produce a 100 Watt sine-wave into its load. With music, the total actual power would be less. With a square-wave, it would be more.

RMS, saat pengukuran power mempunyai arti ” sine-wave power“. Amplifier 100 Watt ” RMS” berarti menghasilkan tenaga 100 Watt sine-wave ke dalam bebannya. Dengan dibebani musik, total power nyatanya, ternyata berkurang. Dengan mengumpanii square-wave maka akan lebih meningkat. Mengapa demikian?.

DIN power

The DIN 45000 defines different methods to measure power, depending on the device under test. Well, this is what I remember from reading the DIN some 25 years ago.

For home applicances there are three different numbers for power: Continous power, Peak power and power bandwidth; the latter does not apply for speakers.

DIN 45000 menggambarkan metoda lain untuk mengukur power, tergantung alat testernya, ini yang harus diingat saat mempelajari DIN yang berlaku 25 tahun lampau.

Untuk peralatan rumah tangga ada tiga perbedaan pokok tentang normalisasi power yaitu : continous power, Peak Power dan power bandwidth. Yang terakhir tidak diaplikasikan pada speaker.

Power measurement of an amp requires that the amp is properly terminated by Ohmic resistances of nominal value both at input and output. The continous power is measured when the amp is supplied by its normal power supply. It must then be able to deliver the rated power at 1 kHz for at least 10 minutes while the maximum THD does not exceed 1 %. To measure the peak power the normal power supply is replaced by a regulated power supply and the time for delivering the power is reduced. Thus, higher values for peak power are obtained. You may skip measuring the peak power by simply multiplying the continuous power by 1.1.

Pengukuran amplifier memerlukan nilai hambatan Ohmic dari nilai nominal kedua- masukan dan keluaran. Continous power diukur ketika amp disuplai oleh normal power supply. Kemudian bisa mengirim power rating power 1 kHz sedikitnya 10 menit saat maksimum THD tidak melebihi 1%. Untuk mengukur daya puncak power yang normal digantikan oleh penggunaan power supply yang terserap olehnya. Seperti itulah nilai tertinggi untuk daya puncak dapat diperoleh. Kita boleh mengabaikan pengukuran daya puncak dengan hanya mengalikan continous power dengan perkalian : 1×1.

The power bandwidth is defined as the bw for which 1/2 of the rated continous power can be obtained.

Actually, DIN 45 500, CNF 97-330, EIA RS-426 and the encompassing IEC 268-5 specify not pink noise, but pink noise filtered by a filter that provides sinificant attenuation in the low and high frequency region of the spectrum to more closely model the long-term spectral distribution of music. Pink noise itself does not accomplish this

Power bandwitdh digambarkan sebagai bw di mana 1/2 dari rating continous power dapat diperoleh.

Sebenarnya , DIN 45 500, CNF 97-330, EIA RS-426 yang mencakup IEC 268-5 tidak menspesifikasikan bising merah muda (Pink noise), tetapi bising merah muda yang disaring oleh suatu penekanan penyaringan yang sinificant di daerah frekwensi tinggi dari rendah dari spektrum kepada mode long term spectral distribusi musik. Pink noise sendiri tidak memenuhi kriteria ini

PMPO (Peak Music Power)

So called “music power”. This power figure tells the power which the amplifier can maximally supply in some conditions. PMPO rating gives the highest measuring value, but this info is quite useless, because there is no exact standard how PMPO power should be measured.

Sekarang lagi trend orang menyebut : ” music power “. Sebenarnya figure ‘power’ tersebut berusaha menjelaskan pada kondisi yang mana amplifier dapat secara maksimal menyediakan sumber tenaga. Rating PMPO maksudnya memberi nilai pengukuran maksimum, tetapi informasi ini sebenarnya tidak relevan sebab tidak ada standard yang tepat bagaimana power PMPO terukur.

The reason for this power rating was to show the max capability of equippment for recreating strong musical tansients like kettle drums and the like. Similar thing (music power rating) was used in the sixties, and I think it assumed a square wave that swung the whole supply range of the output stage. This alone gives them a factor of two over a clean sine wave note.

Alasan power rating maksimum ini adalah hanya menunjukkan kemampuan maximum equipment untuk melukiskan kekuatan transient dalam hal musical seperti dentuman perkusi Drums yang digunakan sejak tahun 60 an. Asumsinya adalah ada sebuah gelombang persegi yang mengayun pada jangkah suplai terhadap tingkatan output yang memberikan satu factor terhadap dua sinyal over pada sebuah gelombang sinus bersih yang lewat.

But the ugliest thing they did was to assume that the high power lasted such a short period of time that the power supply caps would hold the voltages steady without any drooping. In the real world, an under powered PS could be hidden by this ruse and the PMPO might be a factor of 10 or more higher than what could be sustained on a nice instrumental performance.

Tetapi hal paling buruk bagi asumsi ini adalah bahwa kualitas high power seperti layaknya perioda pendek kemampuan power suplly untuk menahan stabilitas tegangan tanpa adanya droping diabaikan. Pada kenyataannya penampilan PSU untuk mengatasi masalah perhitungan PMPO ini harus memperhitungkan factor 10 tiap power rating ditingkatkan volumenya yang tentunya mempengaruhi penampilan kualitas musik.

Forget what adverts say about peak power or other “power terms” because they are not standardized and anyway comparable between equipments. Just look for “RMS continuous Power” or other reliable power rating (like DIN power).

Maka dari itu mari kita lupakan perdebatan sengit tentang terminology ‘Peak power’ (istilah itu hanya salah kaprah dan umum) yang sebenarnya tidak ada standarisasi yang cocok diterapkan di banyak equipment. Kita hanya mereferensikan “RMS continous power” atau badan standarisasi yang dapat dipercaya seperti DIN power.

Speaker power ratings

The nominal power for speakers is defined quite differently: The continous power is measured by pink noise rather than a sinousoidal signal and it is applied for 24 hours. Bandwidth of the noise is as required/specified by the speaker. Thus the nominal power is applicable to both a single chassis/driver and complete box.

Perhitungan nominal power untuk speaker dapat dijelaskan dengan jalan: Continous power diukur dengan generator pink noise berbanding dengan sinyal sinus yang diaplikasikan selama 24 jam penuh. Lebar bidang noise harus sesuai dengan spesifikasi speaker. Kemudian nilai nominal powernya dapat dilaksanakan dengan driver dan desain boxnya.

And the THD is not the limiting factor: It is replaced by the term that the speaker should by no means be damaged. Rhe requirement is that the speaker meet the manufacturers performance sapecification after the power cycle.

The maximum power is defined for woofers and boxes only. It is measured by applying sinusoidal signals of 250 Hz and lower such that the speaker is neither damaged nor produces unwanted output.

THD tidak membatasi limiting factor dengan terminology bahwa sampai dimana kesanggupan speaker menampung daya dan tidak sampai rusak. Tentu harus dipelajari spesifikasi pabrik pembuat speaker sebelum pengujian.

The AES/ANSI spec provides for two power measurements: thermal power, as you describe above, and excursion limiting, which is determined by either the hard mechanical limits afforded by the suspension, or the difference between the length of the voice coil and the length of the magnetic gap.

Spec. AES/ANSI telah mengembangkan dua tolok ukur pengukuran cermat lain : Thermal power seperti yang disebutkan di atas dan pembatasanya dimana ada pendekatan hal lain seperti (melihat dulu) mekanikal speaker pada kelenturan suspensi speaker atau jarak antara voice coil dan jarak celah magnet speaker.

Other amplifier specifications

Speaker impedance the amplifier is designed to drive

Many amps manufactured these days are rated only for 8-ohm-and-above loads, and not for 4-ohm loads. This is done largely as a cost savings by the manufacturer. Amps which are capable of driving 4-ohm loads to the same output voltage require heftier power supplies, heatsinks, and (often) output-stage transistors: they’ll be delivering twice as much current into the load, and will be dissipating roughly twice as much heat within their output stages.

Kini banyak pembuat amplifier menyediakan rating beban speaker sebesar 8 ohms dan bukannya 4 ohms. Maksud dari semua ini adalah dengan alasan menghemat daya power suplly dan keping pendingin pada transistor akhir dimana semakin besar dayanya semakin besar pula disipasi daya yang terhambur pada finalnya.

If a manufacturer chooses to quote a power rating at 4 ohms in their advertising, the amp must be capable of delivering this much power after a ‘warmup’ period of operation at 1/3 power (which level actually dissipates _more_ heat in the output stage than full-power operation).

Jika ada pabrikan mengklaim power buatanya berating sanggup mengatasi beban pada 4 ohms, amplifier buatannya harus mampu mensuplai banyak tenaga selama “warm up” period untuk pengoperasian pada 1/3 tenaga yang mana dilevel itu sudah banyak pemborosan daya yang memancar sebagai panas selama pengoperasian penuh!. Kesimpulanya beban impedansi 4 ohm bukan alasan untuk mendongkrak performance amplifier.

In order to save money during manufacture, manufacturers often use skimpier power supplies, heatsinks, and output stages – and as a result, the amps may have a 4-ohm power rating which is _less_ than the 8-ohm rating. This is somewhat embarrassing for the manufacturer to advertise – and, so, they often do not quote a 4-ohm power rating at all, and state that the amp is designed to be used only with loads of 8 ohms or above.

Untuk mengatasi hal itu dibutuhkan desain yang menelan biaya mahal. Pembuat amplifier biasanya mengatasinya dengan “skimpier” power supply, keping pendingin lebih tebal dan lapis multi final pada outputnya dibanding desain 8 ohms. Padahal desain-desain itu lebih aman beroperasi pada beban 8 ohm ke atas.

With many such amplifiers, you can drive a 4-ohm load safely, as long as you don’t try to drive it too hard. If you drive a low-Z load to too high a volume, one of several things may happen: the amp may begin to “clip” (sounds very harsh and distorted, may damage the tweeters), or may overheat and shut itself down, or may overheat and burn up (all the magic blue smoke leaks out).

Memang ada beberapa amplifier yang aman beroperasi pada beban 4 ohm, hanya harus diingat jangan terlampau keras memperkosanya dengan volume tinggi dan dengan dentuman bass yang menggebu-gebu!. Ingat! Akan terjadi “clipping” yaitu suara tersendat atau cacat dan dapat membakar coil tweeter dalam sekejab!. Bahaya yang lain yaitu terjadi kebakaran dan pijaran api biru pada peralatan.

Methods for making 4 ohm speaker to appear as 8 ohm

cara membikin speaker 4 ohm menjadi 8 ohm

• Wire a 4-ohm power resistor (10-20 watt) in series with each 4-ohm speaker. This makes the system to be appear as 8 ohm load and is inexpensive. The cons are that the resistor wastes power, may cause frequency response go bad because speakers do not have constant resistance with frequency. When you play at high volumes the resistor may get hot and burn thing or itself.

• Pasang resistor 4 ohm 10-20 watt seri dengan coil speaker. Resistor ini sebagai ballast tapi resikonya memotong bandwidth. Respon frekuensinya jelek dan jangan pasang volume keras-keras karena resistor ini akan terbakar.

• Using 4 ohm to 8 ohm matching transformer will not waste much power, but the transformer will be heavy, expensive and hard to find. Transformer has also problems in playing back lowest frequencies (saturation causes distortion in high levels) and in higher frequencies the inductance in the transformer will cause phase shifts.

• Memakai trafo penyesuai jauh lebih baik hanya ukurannya menjadi berat dan mahal. Resiko yang lain adalah respon pada frekuensi rendah terjadi saturasi yang menyebabkan distorsi. Pada frekuensi tinggi induktansi trafo menyebabkan pergeseran fasa.

• You can wire two 4-ohm speakers in series if you have two identical speakers. Problem is that if the speakers are not identical type the frequency response and power distributin will be uneven.

• Cara yang lebih baik lagi adalah menyeri dua buah speaker yang identik. Hanya saja “identik” disini sangat sukar ditemukan walau sama persis secara fisik, harus betul-betul eksak dan absolute.

• Most “8-ohm” amplifiers can drive a 4-ohm or 6-ohm load as long as you don’t try to get full power out of the amp (if you do, it may overheat and shut down).

• Banyak amplifier 8 ohm dapat beroperasi baik pada 4 atau 6 ohm selama anda suka, namun ingat sekali lagi jangan diperkosa beroperasi penuh pada volume tinggi jika tidak ingin terbakar!.

• Buy yourself a decent power amplifier whose output stage and power supply are capable of handling a real honest low-impedance load. Good amplifier will be expensive but gives best sound quality and reliabity.

• Solusi terakhir jika anda pengidam power ukuran besar; belilah amplifier desain khusus dengan rating power yang sanggup beroperasi pada impedans rendah (tapi mahal dan sulit dapatnya), dijamin memang akan memberikan performa bagus dan memuaskan.

Dampling factor

The output impedance of an amp should be extremely low. If it’s .8 Ohms, then an 8-Ohm speaker has a damping factor of 10. If it’s .08, then the amplifier provides a damping factor of 100, etc. Don’t confuse the actual output (source) impedance with the load impedance that is recommended for the amp (4-Ohms, 8-Ohms, etc).

Impedansi keluaran amplifier bisa jadi rendah sekali. Jika amplifier 8 ohm diumpankan pada speaker 8 ohm memiliki damping factor 10, jika .08 ohm maka dampling faktornya 100 dan seterusnya. Jangan dicampur adukkan antara actual output (sumber) impedansi dengan beban impedansi yang direkomendasikan amplifier 4 ohm, 8 ohm dan seterusnya.

The idea is that if the speaker is 8 Ohms, and the amplifier has a source impedance of .08 Ohms, then the amplifier “damps” the motion of the cone by a “factor” of 100. In reality, the true damping that the cone “sees” is determined by many things, part of which is the damping limitation imposed by the resistance of the voice coil, usually around 5 Ohms or so for an 8-Ohm speaker. You can see that if the speaker has 5 Ohms of resistance, the internal (source) impedance of the amplifier (.08 Ohms for a damping factor of only 100) doesn’t add much to the total resistance in the voice coil circuit, hence has very little effect on total damping. So any modest change in the amplifier damping factor correlates to virtually no change in total damping.

Idealnya speaker 8 ohm itu diumpankan pada sumber impedansi amplifier .08 ohm dimana terjadi peredaman gerakan konus speaker berdasarkan atas factor 100. pada kenyataannya peredaman konus terlihat dalam beberapa hal : misalnya batas resistansi koil speaker, biasanya sekitar 5 ohm atau lebih untuk speaker 8 ohm. Coba anda ukur dengan multi tester harga tahanannya pasti sekitar 5 ohm! Ingat : untuk .08 ohm factor damping nya hanya 100!. Maka dari itu jangan menambahkan harga total resistansi koil suara.

A speaker designer shoots for a certain damping (same as 1/Q) to achieve a certain desired type of low-frequency rolloff. The assumption is that the source impedance of the amplifier is 0 Ohms. If the source impedance is .08 Ohms (damping factor of 100), very little error is introduced into the system. Higher damping factors are getting into diminishing returns in terms of the total damping. In practice we want a certain, relatively low damping figure for the whole speaker system, (1.414 for a maximally flat bass response).

Pendesain speaker menetapkan damping sebagai 1/Q untuk untuk menggambarkan type dari roll-off frekuensi rendah dengan anggapan bahwa sumber impedansi amplifier adalah 0 ohm. Jika sumber impedansi .08 ohm dan faktornya 100 akan terjadi sedikit error pada system. Damping factor yang terlalu tinggi akan mengurangi harga terhadap total dampening faktornya. Dalam prakteknya kita selalu mengidamkan suara merdu bass flat respon secara maksimal.

What is amplifier “bridging” or “monoblocking”?

When you’re told a stereo power amplifier can be bridged, that means that it has a provision (by some internal or external switch or jumper) to use its two channels together to make one mono amplifier with 3 to 4 times the power of each channel. This is also called “Monoblocking” and “Mono Bridging”.

Jika anda bilang : stereo amplifier dapat dijembatankan sebanyak 3 atau 4 lapis per chanel bersama maka hal itu lazim disebut sebagai “mono blocking” atau “mono bridging”

Bridging typical HIFI amplifier involves connecting one side of the speaker to the output of one channel and the other side of the speaker to the output of the other channel. The channels are then configured to deliver the same output signal, but with one output the inverse of the other. The beauty of bridging is that it can apply twice the voltage to the speaker. Since power is equal to voltage squared divided by speaker impedance, combining two amplifiers into one can give four (not two) times the power.

Tipikalnya adalah menggabungkan dua buah amplifier per chanel sekaligus pada satu speaker. Dua buah amplifier itu mengirimkan sinyal bersama tapi lain fasanya/saling menjungkir. Akal-akalan itu memang dapat diperoleh dua kali lipat tegangan pada satu speaker. Awalnya anggapanya diperoleh harga tegangan 4 kali lipat!

In practice, you don’t always get 4 times as much power. This is because driving bridging makes one 8 ohm speaker appear like two 4 ohm speakers, one per channel. In other words, when you bridge, you get twice the voltage on the speaker, so the speakers draw twice the current from the amp.

Sekali lagi dijelaskan disini penggabungan 2 buah amplifier menghasilkan dua kali tegangan dan arus pada speaker bukan 4 kali!. Logikanya pengendalian speaker 8 ohm akan ditampilkan sebagai 4 ohm speaker. Jadi akan mendongkrak daya.

Another interesting consequence of bridging is that the amplifier damping factor is cut in half when you bridge. Generally, if you use an 8 ohm speaker, and the amplifier is a good amp for driving 4 ohm speakers, it will behave well bridging.

Jika anda tertarik menggunakan metoda ini konsekwensinya damping factor akan memotong setengah gelombang sinyal. Jadi harus diperhatikan : metoda ini bagus jika : anda pasang speaker 8 ohm dengan desain amplifier khusus bridge 4 ohm speaker.

Also consider amplifier output protection. Amps with simple power supply rail fusing are best for bridging. Amps that rely on output current limiting circuits to limit output current are likely to activate prematurely in bridge mode, and virtually every current limit circuit adds significant distortion when it kicks in. Remember bridging makes an 8 ohm load look like 4 ohms, a 4 ohm load look like 2 ohms, etc.

Pergunakanlah pengaman speaker karena masalah metoda ini pada pembatasan arus sirkuit terhadap arus keluaran dan pembatasan sirkuit arus semu yang ikut andil dalam hal distorsi bila konus terdorong sinyal. Ingat! Metoda ini membuat beban 8 ohm terlihat sebagai 4 ohm, 4 ohm terlihat sebagai 2 ohm dan seterusnya.

]]> http://yonni1967.wordpress.com/2008/10/02/power-amplifier-tutorial/feed/ 1 yonni1967 pioneer_sa-608_integrated_amplifier_web_small http://yonni1967.wordpress.com/2008/10/02/operating-system/ http://yonni1967.wordpress.com/2008/10/02/operating-system/#comments Thu, 02 Oct 2008 13:58:26 +0000 yonni1967 http://yonni1967.wordpress.com/?p=156 ]]>

Bagi teman-teman pelajar, mahasiswa dan umum yang mengikuti program study dan pendalaman materi Operating System dapat mendown load file berikut ini yaitu mengenai sistim operasi : Windows, Unix dan Linux dalam versi format PDF.

For students and publics who’s concerning program in Operating System easy download this following items of the file operation systems lecture notes like : Windows, Unix and Linux in PDF format.

sisitem-operasi

linux

komputer1

Daftar alamat kantor samsat di

jawa timur

KB. Samsat	Alamat	telephone
Surabaya A	Jl. Manyar Kertoarjo No. 1	031 596 1512-6
Surabaya B	Jl. Ketintang Seraten	031 829 5393-4
Mojokerto	Jl. Achmad Basuni No. 54	0321 324 244
Gresik	Jl. Dr. wahidin no. 480	031395 5170
Sidoarjo	Jl. Lingkar barat	031 805 5136
Jombang	Jl. Brigjen Kretarto	0321 866 9920
Bojonegoro	Jl. Basuki Rachmat	0353 886 264
Lamongan	Jl. Veteran no. 1	0322 322 559
Tuban	Jl. Teuku Umar no. 18	0356 322 548
Madiun kota	Jl. Pahlawan no. 25-27	0351 463 315
Madiun kabupaten	Jl. Ponorogo no. 66	0351 463 398
Ngawi	Jl. Hasanudin no. 56	0351 749 302
Magetan	Jl. Kunti no. 1	0351 895 372
Ponorogo	Jl. Ir. Juanda no. 39	0352 483 088
Pacitan	Jl. Achmad yani no. 60	0357 882 909
Kediri kabupaten I	Jl. Kusuma Bangsa, Pare	0354 391 554
Kediri kabupaten II	Jl. Soekarno Hatta 12	0354 682 571
Kediri kota	Jl. Super semar no. 80	0354 689 518
Blitar	Jl. Melati no. 17	0342 801 455
Tulung Agung	Jl. Wahidin Sudiro. Husodo	0355 323 810
Trenggalek	Jl. Mangun Sarkoro no. 9	0355 791 639
Nganjuk	Jl. Anjuk Ladang	0358 325 335
Malang kota	Jl. S. supriyadi no. 80	0341 801 303
Malang kabupaten I	Jl. A. Yani, Kepanjen	0341 395 599
Malang kabupaten II	Jl. Karang Ploso	0341 463 234
Malang kabupaten III	Batu	0341 590 322, 590 320
Pasuruan	Jl. Sultan Agung 80	0343 426 625
Probolinggo	Jl. Basuki rachmat no 11	0335 427 883
Lumajang	Jl. Pisang Agung	0334 882 538
Jember kabupaten	Jl. Teratai no. 10	0331 424 224
Bondowoso	Jl. Achmad Yani no 84	0332 421 012
Situbondo	Jl. Raung	0338 670 652
Banyuwangi	Jl. Adi Sucipto no. 10	0333 426 399
Pamekasan	Jl. Wachid Hasyim no. 11	0324 321 495
Sampang	Jl. Syamsul Arifin	0323 323 812
Bangkalan	Jl. Halim Perdana Kusumah no. 1	031 309 7015
Sumenep	Jl. KH. Mansyur no. 234	0328 662 834

Berikut data yang dapat saya sampaikan untuk dipergunakan dengan baik dan benar.

what is the Thermocouple?

In electrical engineering and industry, thermocouples are a widely used type of temperature sensor and can also be used as a means to convert thermal potential difference into electric potential difference.They are cheap and interchangeable, have standard connectors, and can measure a wide range of temperatures. The main limitation is accuracy; System errors of less than one degree Celsius (°C) can be difficult to achieve

History

In 1821, the German–Estonian physicist Thomas Johann Seebeck discovered that when any conductor (such as a metal) is subjected to a thermal gradient, it will generate a voltage. This is now known as the thermoelectric effect or Seebeck effect. Any attempt to measure this voltage necessarily involves connecting another conductor to the “hot” end. This additional conductor will then also experience the temperature gradient, and develop a voltage of its own which will oppose the original. Fortunately, the magnitude of the effect depends on the metal in use. Using a dissimilar metal to complete the circuit creates a circuit in which the two legs generate different voltages, leaving a small difference in voltage available for measurement. That difference increases with temperature, and can typically be between 1 and 70 microvolts per degree Celsius (µV/°C) for the modern range of available metal combinations. Certain combinations have become popular as industry standards, driven by cost, availability, convenience, melting point, chemical properties, stability, and output. This coupling of two metals gives the thermocouple its name.

Thermocouples measure the temperature difference between two points, not absolute temperature. In traditional applications, one of the junctions—the cold junction—was maintained at a known (reference) temperature, while the other end was attached to a probe.

Having available a known temperature cold junction, while useful for laboratory calibrations, is simply not convenient for most directly connected indicating and control instruments. They incorporate into their circuits an artificial cold junction using some other thermally sensitive device, such as a thermistor or diode, to measure the temperature of the input connections at the instrument, with special care being taken to minimize any temperature gradient between terminals. Hence, the voltage from a known cold junction can be simulated, and the appropriate correction applied. This is known as cold junction compensation.

Additionally, a device can perform cold junction compensation by computation. It can translate device voltages to temperatures by either of two methods. It can use values from look-up tables or approximate using polynomial interpolation.

A thermocouple can produce current, which means it can be used to drive some processes directly, without the need for extra circuitry and power sources. For example, the power from a thermocouple can activate a valve when a temperature difference arises. The electric power generated by a thermocouple is a conversion of the heat energy that one must continuously supply to the hot side of the thermocouple to maintain the electric potential. The flow of heat is necessary because the current flowing through the thermocouple tends to cause the hot side to cool down and the cold side to heat up (the Peltier effect).

Thermocouples can be connected in series with each other to form a thermopile, where all the hot junctions are exposed to the higher temperature and all the cold junctions to a lower temperature. The voltages of the individual thermocouples add up, allowing for a larger voltage and increased power output, thus increasing the sensitivity of the instrumentation. With the radioactive decay of transuranic elements providing a heat source this arrangement has been used to power spacecraft on missions too far from the Sun to utilize solar power.

Thermocouple materials are available in several different metallurgical formulations per type, such as: (listed in decreasing levels of accuracy and cost) Special limits of error, Standard, and Extension grades. Extension grade wire is less costly than dedicated thermocouple junction wire and it’s usually specified for accuracy over a more restricted temperature range. Extension grade wire is used when the point of measurement is farther from the measuring instrument than would be financially viable for standard or special limits materials, and has a very similar thermal coefficient of EMF for a narrow range (usually encompassing ambient). In this case, a standard or special limits wire junction is tied to the extension grade wire outside of the area of temperature measurement for transit to the instrument. Since most modern temperature measuring instruments that utilize thermocouples are electronically buffered to prevent any significant current draw from the thermocouple, the length of the thermocouple or extension wire is irrelevant.

Changes in metallurgy along the length of the thermocouple (such as termination strips or changes in thermocouple type wire) will introduce another thermocouple junction which affects measurement accuracy. Also, in the United States, industry standards are that the thermocouple color code is used for the insulation of the positive lead, and red is the negative lead.

Types…………:

A variety of thermocouples are available, suitable for different measuring applications. They are usually selected based on the temperature range and sensitivity needed. Thermocouples with low sensitivities (B, R, and S types) have correspondingly lower resolutions. Other selection criteria include the inertness of the thermocouple material, and whether or not it is magnetic. The thermocouple types are listed below with the positive electrode first, followed by the negative electrode.

Type K (chromel–alumel) is the most commonly used general purpose thermocouple. It is inexpensive and, owing to its popularity, available in a wide variety of probes. They are available in the −200 °C to +1350 °C range. The type K was specified at a time when metallurgy was less advanced than it is today and, consequently, characteristics vary considerably between examples. Another potential problem arises in some situations since one of the constituent metals, nickel, is magnetic. One characteristic of thermocouples made with magnetic material is that they undergo a step change when the magnetic material reaches its Curie point. This occurs for this thermocouple at 354°C. Sensitivity is approximately 41 µV/°C.

Type E

Type E (chromel–constantan) has a high output (68 µV/°C) which makes it well suited to cryogenic use. Additionally, it is non-magnetic.

Type J

Type J (iron–constantan) is less popular than type K due to its limited range (−40 to +750 °C). The main application is with old equipment that cannot accept modern thermocouples. J types cannot be used above 760 °C as an abrupt magnetic transformation causes permanent decalibration. The magnetic properties also prevent use in some applications. Type J thermocouples have a sensitivity of about 50 µV/°C.

Type N

Type N (nicrosil–nisil) thermocouples are suitable for use at high temperatures, exceeding 1200 °C, due to their stability and ability to resist high temperature oxidation. Sensitivity is about 39 µV/°C at 900°C, slightly lower than type K. Designed to be an improved type K, it is becoming more popular.

Type B, R, and S

Types B, R, and S thermocouples use platinum or a platinum–rhodium alloy for each conductor. These are among the most stable thermocouples, but have lower sensitivity, approximately 10 µV/°C, than other types. The high cost of these makes them unsuitable for general use. Generally, type B, R, and S thermocouples are used only for high temperature measurements.

Type B thermocouples use a platinum–rhodium alloy for each conductor. One conductor contains 30% rhodium while the other conductor contains 6% rhodium. These thermocouples are suited for use at up to 1800 °C. Type B thermocouples produce the same output at 0 °C and 42 °C, limiting their use below about 50 °C.

Type R thermocouples use a platinum–rhodium alloy containing 13% rhodium for one conductor and pure platinum for the other conductor. Type R thermocouples are used up to 1600 °C.

Type S thermocouples use a platinum–rhodium alloy containing 10% rhodium for one conductor and pure platinum for the other conductor. Like type R, type S thermocouples are used up to 1600 °C. In particular, type S is used as the standard of calibration for the melting point of gold (1064.43 °C).

Type T

Type T (copper–constantan) thermocouples are suited for measurements in the −200 to 350 °C range. Often used as a differential measurement since only copper wire touches the probes. As both conductors are non-magnetic, type T thermocouples are a popular choice for applications such as electrical generators which contain strong magnetic fields. Type T thermocouples have a sensitivity of about 43 µV/°C.

Type C

Type C (tungsten 5% rhenium – tungsten 26% rhenium) thermocouples are suited for measurements in the 0 °C to 2320 °C range. This thermocouple is well-suited for vacuum furnaces at extremely high temperatures and must never be used in the presence of oxygen at temperatures above 260 °C.

Type M

Type M thermocouples use a nickel alloy for each wire. The positive wire contains 18% molybdenum while the negative wire contains 0.8% cobalt.These thermocouples are used in the vacuum furnaces for the same reasons as with type C. Upper temperature is limited to 1400 °C. Though it is a less common type of thermocouple, look-up tables to correlate temperature to EMF (milli-volt output) are available.

Type Chromel-gold/iron

In chromel-gold/iron thermocouples, the positive wire is chromel and the negative wire is gold with a small fraction (0.03–0.15 atom percent) of iron. It can be used for cryogenic applications (1.2–300 K and even up to 600 K). Both the sensitivity and the temperature range depends on the iron concentration. The sensitivity is typically around 15 µV/K at low temperatures and the lowest usable temperature varies between 1.2 and 4.2 K.

Thermocouple comparison

The table below describes properties of several different thermocouple types. Within the tolerance columns, T represents the temperature of the hot junction, in degrees Celsius. For example, a thermocouple with a tolerance of ±0.0025×T would have a tolerance of ±2.5 °C at 1000 °C.

Applications

Thermocouples are most suitable for measuring over a large temperature range, up to 1800 °C. They are less suitable for applications where smaller temperature differences need to be measured with high accuracy, for example the range 0–100 °C with 0.1 °C accuracy. For such applications, thermistors and resistance temperature detectors are more suitable.

Steel industry

Type B, S, R and K thermocouples are used extensively in the steel and iron industries to monitor temperatures and chemistry throughout the steel making process. Disposable, immersible, type S thermocouples are regularly used in the electric arc furnace process to accurately measure the steel’s temperature before tapping. The cooling curve of a small steel sample can be analyzed and used to estimate the carbon content of molten steel.

Heating appliance safety

Many gas-fed heating appliances such as ovens and water heaters make use of a pilot light to ignite the main gas burner as required. If the pilot light becomes extinguished for any reason, there is the potential for un-combusted gas to be released into the surrounding area, thereby creating both risk of fire and a health hazard. To prevent such a danger, some appliances use a thermocouple as a fail-safe control to sense when the pilot light is burning. The tip of the thermocouple is placed in the pilot flame. The resultant voltage, typically around 20 mV, operates the gas supply valve responsible for feeding the pilot. So long as the pilot flame remains lit, the thermocouple remains hot and holds the pilot gas valve open. If the pilot light goes out, the temperature will fall along with a corresponding drop in voltage across the thermocouple leads, removing power from the valve. The valve closes, shutting off the gas and halting this unsafe condition.

Some systems, known as millivolt control systems, extend this concept to the main gas valve as well. Not only does the voltage created by the pilot thermocouple activate the pilot gas valve, it is also routed through a thermostat to power the main gas valve as well. Here, a larger voltage is needed than in a pilot flame safety system described above, and a thermopile is used rather than a single thermocouple. Such a system requires no external source of electricity for its operation and so can operate during a power failure, provided all the related system components allow for this. Note that this excludes common forced air furnaces because external power is required to operate the blower motor, but this feature is especially useful for un-powered convection heaters.

A similar gas shut-off safety mechanism using a thermocouple is sometimes employed to ensure that the main burner ignites within a certain time period, shutting off the main burner gas supply valve should that not happen.

Out of concern for energy wasted by the standing pilot, designers of many newer appliances have switched to an electronically controlled pilot-less ignition, also called intermittent ignition. With no standing pilot flame, there is no risk of gas buildup should the flame go out, so these appliances do not need thermocouple-based safety pilot safety switches. As these designs lose the benefit of operation without a continuous source of electricity, standing pilots are still used in some appliances.

Thermopile radiation sensors

Thermopiles are used for measuring the intensity of incident radiation, typically visible or infrared light, which heats the hot junctions, while the cold junctions are on a heat sink. It is possible to measure radiative intensities of only a few μW/cm² with commercially available thermopile sensors. For example, some laser power meters are based on such sensors.

Manufacturing

Thermocouples can generally be used in the testing of prototype electrical and mechanical apparatus. For example, switchgear under test for its current carrying capacity may have thermocouples installed and monitored during a heat run test, to confirm that the temperature rise at rated current does not exceed designed limits.

External links : 

• NIST ITS-90 Thermocouple Database

• Thermocouple design guide

• Notes from a cold junction

• Mineral-Insulated Thermocouple Know-How

• Thermocouple Color Code Chart and Specifications

• Thermocouple Reference Information

Retrieved from “http://en.wikipedia.org/wiki/Thermocouple“

Categories: Heating, ventilating, and air conditioning | Thermometers | Sensors

]]> http://yonni1967.wordpress.com/2008/09/13/what-is-the-thermocouple/feed/ 1 yonni1967 gambar-tc1 http://yonni1967.wordpress.com/2008/09/13/method-of-servicing-electronic-equipment/ http://yonni1967.wordpress.com/2008/09/13/method-of-servicing-electronic-equipment/#comments Sat, 13 Sep 2008 14:37:15 +0000 yonni1967 http://yonni1967.wordpress.com/?p=87 ]]>

Method of servicing electronic equipment.

The standard tool

By : Yonni Muhazir.

uwiga malang

In the first time if us on servicing electronic goods we think intricate network and make confusedly head. First step is bring damage goods to expert serviceman and buy his services. That is fair…..because improve of repairing electronic goods do not easy as which predicted most societies. Need an education and some practice have to many years to be able handle damage of electronic equipments. Experience of my self was a hard learn electronic skill from kiddy till now. To do that, I invite to all beginners which interest in the field of services electronic with me. I have finished my half age self-study and through by valuable experience. finally blessing by my school in result combination college and experience during many years I have succeeded of giving competent my family life blessing by that skilled.

Commonly…..Opening content of electronic box, initially it is true confuse have to, isn’t it? First question where we have to do start from this?. The visible is intricate of small cable and many path make confuse. Initially me, also that way too. Don’t be doleful, passing a little base lesson of electronics knowledge now will be reveal.

Early mind is feeling vexed, why this equipments can work ?. That just have enough ?. Both second step is human sense of base and enquire in itself : there is a way or systems taking care of this equipments so that like having soul. In this case I think back to nature that if ” something that take care of …” that out of sevice, so…. hence like a missing soul. Then…such as you think, hence the equipments will be “ die ”.

The “ Death ” of the electronics equipments caused by in-existence of electric current rationing to it. If human being have soul, hence the soul of electronics equipments is the electrics current – existence of it. Commonly trouble electrics current existence sometime indirectly “off” or lose but sometime there is can be chocked. This last situation so-called as “ sick ” cranky pain. This trouble happened caused by direct linking “short circuit” or “ intermitten ” connecting. Sometime also happened caused by component is out of age. Continuous and long-range exceed operation also can destroy this equipments. Also encumbering more exceed capacities causing over heating. The unstableness electricity from the stop contack also cause damage too. Most more because by follow consumer shares of carelessness conducted in this case.

Return to the ” soul ” was mentioned it, so… electrics current have stabilize passing without any disturbance!. Just a little trouble goes there, hence will happened like handicap performance at here!

Kinds of that trouble is :

• If that trouble at visual, looked into eye was bad picture, trouble example at TV equipment.

• If that trouble at voice, hence will be heard by hearting voice of our ear, follow the example at sound equipments.

• If that trouble at digital equipments kinds of numerator machine or computer, hence will be happened chaos arrangement of data and even will be “ hang “ !.

Then…. what method we must do in investigating above electrics current?. We have to assume that electrics current is the same precisely as water current character. Analogy electrics current measure is equal with flow of water where if current in a pipe stuff up hence happened stop current. Equipments to test and analyse electric current is :

• Avometre. This appliance good for analyzing an electronics existence of voltage, electrics current and resistance. This appliance have to always attend in a technician workbench and is standart technician equipments.

• Osciloscope. This equipments is a standard laboratory but do not always have to attend in beginner technician workbench.

In real factual of me, I am just  only requiring an Avometre, a tool set which compose from : some screwdriver, some kinds of forcepses, good quality soldering iron and that have last for search my earning life… ha..ha…ha…really..!!. and in experience day of my day I look for correct payment of me just rely on that simple equipments, but have succeeded all sort damage of electronics equipments. The secret is to treat electrics current as a real friend. Another secret again is to assuming electronics equipments as divided into some black box and in the handling of that was repair improve in per black box shares. This is important before you correct plunge into world business service of repairing electronic : ad for you have to honesty, at second, having to tough when remembering this world is struggle with a state :” something wrong and have to correct “. Don’t be to easy fulminate, and don’t be easy to stress..!!!!….

Best regards

Yonni 

in

Malang town

of

Indonesia

Mailto: yonni_1967@yahoo.co.id or yonni.muhazir@gmail.com

This is Invite to…..: All Malang town Hobbyiest electronics community ( Almahobel ). Hello..? Are you there ? Let us keep community forming such as have there be.. is….