Welding inverter is an alternative to a conventional welding transformer. Modern semiconductors allow to replace the traditional mains transformer with a
switching power supply, which is much lighter, smaller and allows easy current adjustment via a potentiometer. The advantege is
also that the output current is DC. DC current is less dangerous than AC and prevents arc extinction.
For this inverter i chose topology, which is the most common in welding inverters - forward converter with two switches.
In my article about switchning supplies it is a topology II.D.
Input mains voltage passes through an EMI filter and is smoothed with high capacity capacitors. Since the inrush current of those capacitors would be too high,
there's a softstart circuit. After switching ON, the primary smoothing capacitors are charging via resistors, which are later bypassed
by the contact of a relay. As power switches, IGBT transistors IRG4PC40W are used.
They are driven through a forward gate-drive transformer TR2 and shaping circuits with BC327 PNP transistors.
The control integrated circuit is UC3844. It's similar to UC3842, but it has its pulse-width limited to 50%. Working frequency is 42kHz.
Control circuit is powered by an auxiliary power supply of 17V.
Current feedback, due to high currents, is using a current transformer Tr3. Voltage drop accros the sensing resistor 4R7/2W is approximately proportional to the output current.
Output current can be controlled by potentiometer P1, which determines the threshold of the current feedback. Threshold voltage of the pin 3 of UC3844 (current sensing) is 1V.
Power semiconductors require cooling. Most of the heat is dissipated in output diodes. Upper diode, consisting of 2x DSEI60-06A, must in worst
case handle the average current of 50A and the dissipation of 80W (total of both diodes).
Lower diode STTH200L06TV1 (doube diode package with both internal diodes connected in parallel) must in worst
case handle an average current of 100A and the dissipation of nearly 120W. Maximum total dissipation of the secondary rectifier is 140W. The heatsink must be able to handle it.
To the thermal resistance you must include the junction-case Rth, case-sink Rth and sink-ambient Rth.
DSEI60-06A diodes don't have insulation pads and the cathode is connected to the the heatsink. Output choke L1 is therefore in the negative rail. It
is advantageous because in this configuration, there's no high-frequency voltage on the heatsink.
You can use another type of diodes, for example a parallel combination of a sufficient number of the most accessible diodes,
such as MUR1560 or FES16JT. Note that the maximum average current of the lower diode is twice the current of the upper diode.
Calculation of the power dissipation of the
IGBTs is more complicated because in addition to conductive losses there are also switching losses. Loss of each transistor is up to about 50W.
It is also necessary to cool the reset diodes UG5JT and the mains bridge rectifier. The power dissipation of the reset diodes depends on the construction of Tr1
(inductance, stray inductance), but is much lower than the dissipation of the IGBTs. The rectifier bridge has a power dissipation of up to about 30W.
UG5JT diodes and the rectifying bridge are placed on the same heatsink as the IGBTs. UG5JT diodes
also can be replaced with MUR1560 or FES16JT or other ultrafast diodes.
During construction it is also necessary to decide the maximum loading factor of the welding inverter, and accordingly select size of heatsinks, winding gauges and so on.
It is also good to add a fan.
Switching transformer Tr1 is wound on two ferrite EE cores, each with a central column cross section 16x20mm. The total cross section is therefore
16x40mm, the core must have no air gap. 20 turns primary winding is wound using 14 wires of a 0.5 mm diamater. It would be better to use 20 wires, but they
didn't fit into my core.
Secondary winding has 6 turns of a copper strip (36 x 0.5 mm). Forward gate-drive transformer Tr2 is made with an emphasis on low stray inductance. It is trifillary wound,
using three twisted insulated wires of 0.3 mm diameter, and all the windings have 14 turns. Core is made of material H22, middle column has a diameter of 16mm, with no gaps.
Current sensing transformer Tr3 is made from an EMI suppression choke on a toroidal core. The original winding with 75 turns of 0.4 mm wire works as a secondary.
Primary has just 1 turn. Polarity of all the transformer windings must be kept (see dots in schematic)!
L1 inductor has a ferrite EE core, middle column has cross section 16x20mm. It has 11 turns of a copper strip (36 x 0.5mm) and the total air gap in the magnetic circuit is 10mm.
Its inductance is cca 12uH.
The auxiliary 17V switching power supply, including Tr4, is described in more detail
here.
The simplest welding inverter on Pic 1 has no voltage feedback. Voltage feedback does not affect the welding, but affects the power consumption and heat losses in the idle state.
Without the output voltage feedback there is quite high output voltage (approximately 100V)
and the PWM controller ia running at its max duty cycle, thereby increasing the power consumption and heating of components.
Therefore, it is better to implement the voltage feedback. You can inspire on Pic 2. The feedback can be connected directly because the controll circuit is
isolated from mains. The reference voltage is 2.5V. Select the R2 to set the open circuit voltage.
You can find useful info in datasheet of UC3842, 3843, 3844, 3845 or in its another datasheet.
Inspiration for modifications you can also find in 3-60V 40A supply.
Interesting links from which I drew:
http://svarbazar.cz/phprs/index.php?akce=souvis&tagid=3
http://leo.wsinf.edu.pl/~leszek/spawarki/
http://www.y-u-r.narod.ru/Svark/svark.htm
http://www.emil.matei.ro/weldinv3.php
http://nexor.electrik.org/svarka/barmaley/kosoy/shema.gif
and a little modified: http://nexor.electrik.org/svarka/barmaley/kosoy1/shema.gif
Cerita berlatar di sebuah penjara swasta di Arizona, AS, yang dikelola secara kacau oleh seorang direktur sadis bernama Bill Boss (diperankan oleh Dieter Laser, aktor dari film pertama) dan bendahara pengecutnya, Dwight Butler (Laurence R. Harvey, aktor dari film kedua).
Bagi Anda yang penasaran ingin menyaksikan kegilaan seorang penjara bernama Bill Boss, artikel ini akan membahas sinopsis, pemain, perbedaan dengan dua film sebelumnya, serta berbagai cara legal dan aman untuk .
Menyediakan opsi sewa dengan kualitas visual terbaik dan pilihan takarir ( subtitle ) yang bisa disesuaikan.
Berhati-hatilah saat mengunduh file dari internet. Pastikan perangkat Anda memiliki keamanan siber yang mumpuni untuk menghindari risiko malware, karena banyak situs penyedia subtitle gratisan sering kali menyalahgunakan tautan unduhan untuk menyebarkan virus atau adware yang merugikan.
: Terinspirasi langsung setelah menonton film The Human Centipede 1 dan 2 (film ini menggunakan konsep meta-fiction ), Dwight mengusulkan sebuah solusi radikal untuk menghemat anggaran makanan sekaligus memberikan efek jera mutlak: menyatukan 500 narapidana menjadi satu jalur pencernaan raksasa. Daftar Pemain Utama nonton human centipede 3 sub indo
The Human Centipede 3 (Final Sequence) remains a polarizing artifact of 21st-century horror. Whether viewed as a satirical masterpiece or a descent into needless depravity, its existence continues to fuel debates on censorship and artistic freedom. For the Indonesian digital audience, the search for the film represents a persistent curiosity with the "unwatchable," proving that no matter how extreme the content, there will always be a community ready to translate and engage with the fringes of cinema.
Beberapa situs meminta Anda menyetujui notifikasi atau mengisi data tertentu yang bisa berujung pada peretasan akun pribadi.
Bagi Anda penggemar film horor ekstrem, kata kunci pasti sudah tidak asing lagi. Sebagai penutup dari trilogi body horror paling kontroversial di dunia, film The Human Centipede 3 (Final Sequence) besutan sutradara Tom Six hadir dengan skala yang jauh lebih besar, lebih gila, dan 100% tidak ramah bagi penonton berparu-paru lemah .
Meskipun situs-situs ilegal seperti , Lk21 , atau Dutafilm mungkin menawarkan akses gratis ke film ini, kami sangat tidak menyarankan penggunaan situs tersebut. Ada beberapa bahaya signifikan yang mengintai: Cerita berlatar di sebuah penjara swasta di Arizona,
Sebelum Anda memutuskan untuk mencari tautan nonton, ada beberapa hal penting terkait konten film ini yang perlu Anda ketahui:
Bagi para pencinta film horor, khususnya subgenre body horror dan exploitation , nama sudah tidak asing lagi. Setelah sukses dengan dua film sebelumnya yang mengguncang dunia, sutradara Tom Six kembali dengan babak terakhir yang paling gila dan kontroversial: The Human Centipede 3 (Final Sequence) .
The story ends when the governor returns to the prison to see the results and finds Bill Boss attempting to take his own life. The whole plot is a grotesque, cruel commentary on the American prison system, a point underlined by the prison's name: the George H.W. Bush State Prison.
Ada sebuah pepatah yang mungkin sangat cocok untuk waralaba film horor The Human Centipede : "Patah di tengah jalan." Jika film pertama (2009) berhasil menciptakan trauma kolektif dengan konsep yang "orisinal" dan menegangkan, dan film kedua (2011) mencoba meta-komentar gelap dengan skala hitam-putih yang depresif, maka hadirnya The Human Centipede 3 (Final Sequence) pada tahun 2015 adalah perjalanan yang sangat berbeda. Menyediakan opsi sewa dengan kualitas visual terbaik dan
Internationally, The Human Centipede 3 appears on a few other major digital storefronts. These include , YouTube Movies , Google Play Movies , Fandango At Home , and AMC+ .
secara legal melalui beberapa platform streaming resmi yang tersedia di Indonesia. Film ini merupakan penutup dari trilogi horor kontroversial karya sutradara Tom Six. Tempat Menonton Resmi di Indonesia
Jika Anda berhasil mendapatkan file video film ini (baik dari pembelian digital atau media fisik), Anda dapat menambahkan subtitle bahasa Indonesia secara mandiri. Situs seperti menyediakan file subtitle Indonesia untuk film ini, yang dapat Anda unduh dan pasangkan (biasanya dengan format .srt ) pada pemutar video seperti VLC atau pada file film Anda.
