HUZOonline

Programmable Logic Controllers (PLCs)

noreply@blogger.com (Membahas tentang teknologi) — Thu, 24 Jan 2013 05:35:00 -0800

Programmable Logic Controllers (PLCs), also referred to as programmable controllers, are in the computer family.They are used in commercial and industrial applications. A PLC monitors inputs, makes decisions based on its program, and controls outputs to automate a process or machine.This course is meant to supply you with basic information on the functions and configurations of PLCs.


PLC (Programmble Logic Controller

Basic PLC Operation PLCs consist of input modules or points, a Central Processing Unit (CPU), and output modules or points. An input accepts a variety of digital or analog signals from various field devices (sensors) and converts them into a logic signal that can be used by the CPU.The CPU makes decisions and executes control instructions based on program instructions in memory. Output modules convert control instructions from the CPU into a digital or analog signal that can be used to control various field devices (actuators). A programming device is used to input the desired instructions.These instructions determine what the PLC will do for a specific input. An operator interface device allows process information to be displayed and new control parameters to be entered.

Pengertian Relay

noreply@blogger.com (Membahas tentang teknologi) — Mon, 24 Dec 2012 22:27:00 -0800

Relay adalah komponen listrik yang dioperasikan sebagai saklar. Beberapa relay menggunakan elektromagnet untuk mengoperasikan pensaklaran secara mekanis, tetapi prinsip-prinsip operasi yang lain juga bisa digunakan. Relay diperlukan untuk mengendalikan rangkaian dengan sinyal daya rendah (dengan isolasi listrik yang lengkap antara kontrol dan rangkaian kontrol), atau di beberapa rangkaian yang harus dikontrol oleh satu sinyal.

Pengertian Relay

Jenis relay yang dapat menangani daya tinggi yang diperlukan untuk secara langsung mengendalikan motor listrik atau beban lainnya disebut kontaktor. Relay solid-state mengontrol rangkaian listrik tanpa menggerakkan komponen, ataupun dengan menggunakan perangkat semikonduktor untuk melakukan switching. Relay sendiri mempunyai dua kondisi yaitu ketika kondis Normaly Open (NO) dan kondisi Normaly Close (NC).

Mikrokontroler Mbed NXP LPC1768

noreply@blogger.com (Membahas tentang teknologi) — Sun, 23 Dec 2012 23:50:00 -0800

Mikrokontroler merupakan perangkat semikonduktor yang terdiri atas mikroprosesor, input output, dan memori yang terdapat dalam satu kemasan chip sehingga mikrokontroler dapat berfungsi sebagai pengontrol dalam suatu alat. Mikrokontroler Mbed NXP LPC1768 adalah salah satu jenis mikrokontroler keluaran ARM yang dirancang khusus terutama untuk Ethernet,USB dan interface dengan perangkat lainnya. LPC1768 merupakan mikrokontroler 32 bit yang memiliki fitur-fitur sebagai berikut :

a) Dapat mencapai kecepatan 96 MIPS (Mega Instruction per Second) pada frekuensi clock 96 MH.

b) 512KB flash memory untuk memori program

c) 32 KB RAM

d) Interface Ethernet

e) USB Host/Device.

f) 2 x SPI (serial peripheral interface).

g) 2 X 12C.

h) Enam saluran untuk penghasil sinyal PWM/clock.

i) 6xADC ( Enam Pin Analog Digital Converter).

j) Mempunyai 40- pin

Mikrokontroler Mbed NXP LPC1768

Mbed NXP LPC1768 memiliki 40 pin dimana masing-masing pin tersebut mempunyai peranan khusus seperti yang dijelasin di atas. Pada mbed juga mempunyai pin ethernet yaitu pin yang bisa digunakan untuk komunikasi yang, secara langsung bisa di hubungkan ke jaringan baik LAN, WAN maupun internet. Untuk power supply mbed sendiri memerlukan tegangan DC 4.5Volt -14 Volt selain itu juga terdapat power supply keluaran atau tegangan out sebesar 5 Volt dan 3.3 Volt. Selain itu mempunyai pin komunikasi serial yaitu pada pin (9 dan 10, 13 dan 14, 27 dan 28) yang bisa digunakan untuk interfacing dengan perangkat yang mempunyai komunikasi serial.

Pada mbed juga mempunyai pin analog input dan analog output yaitu pada pin15 - pin 20 dimana untuk membuat pinnya sebagai analog input atau analog output tergantung nanti di program yang dibuat. Selain itu juga mempunyai pin PwmOut pada kaki pin 21 – pin 26.

Cara kerja komunikasi digital

noreply@blogger.com (Membahas tentang teknologi) — Tue, 26 Jun 2012 08:36:00 -0700

Komunikasi Digital adalah suatu alat yang mengkomunikasikan informasi-informasi digital dari dan ke perlengkapan lainnya. Salah satu keunggulan informasi digital adalah kecenderungan menjadi jauh lebih tahan akan salah transmisi dan interpretasi dari pada informasi yang disimbolkan alam suatu media analog.

Sistem analog adalah sistem komunikasi sederhana dan muda tetapi bukanlah satu-satunya cara. Sistem analog yang sederhana ini memiliki keterbatasan. Salah satunya adalah masalah interferensi sinyal analog. Karena biasanya sinyal yang ditransfer ke pengontrol/layar pembacaan dalam besaran arus listrik DC, maka setiap perubahan/gangguan arus (noise) akan diterjemahkan sebagai perubahan pengukuran juga.

Pada pengukuran level air yang ada di dalam tangki yang menggunakan pelampung (analog) hal ini dapat kita ganti menggunakan serangkaian level switch yang dipasang pada ketinggian yang berbeda pada tangki.

Gambar 1.1 Pengukuran level air menggunkan limit switch

Setiap level switch disambungkan ke rangkaian tertutup, mengirimkan arus ke lampunya masing-masing yang terpasang pada panel di lokasi pemantauan. Setiap switch yang menutup, lampunya akan menyala, dan setiap yang memperhatikan panel akan melihat lima lampu yang merepresentasikan level tangki. Dengan digantinya sinyal analog dengan sinyal digital maka noise yang disebabkan oleh sinyal analog tidak akan terjadi sehingga pembacaan level tangki akan tetap akurat. Tersampaikannya sinyal dari limit switch pada level tangki ke layar pembacaan membutuhkan suatu komunikasi digital.

Komponen dari komunikasi digital adalah :

1. Jaringan dan Bus (Network and Bus)

Sejumlah kumpulan wiring yang menghubungkan antara tangki air dan lokasi pemantauan disebut jaringan (network) atau bus (bus). Istilah “bus” biasanya digunakan sebagai serangkaian wiring penghubung komponen-komponen digital pada perangkat komputer, sedangkan istilah “network” menjangkau jangkuan yang lebih luas lagi bahkan sampai ke seluruh dunia. Bus dibagi menjadi 2 yaitu bus jarak pendek dan jdarak jauh. Yang termasuk bus jarak pendek antara lain : PC/AT, PCI, PCMCIA, VME, VXI dll. Sedangkan untuk yang jarak jauh : RS 232, RS 422A/RS-485, Ethernet, Token ring dll.

2. Aliran Data/Flow

Bus-bus dan jaringan dirancang untuk terjadi komunikasi antara peralatan individual yang interkoneksi. Aliran informasi atau data antara dapat terjadi dalam bentuk simplex dan dulpex communication.

Gambar 1.2 Simplex Communication

Bila semua aliran data searah dari transmitter ke receiver ditentukan hal ini disebut dengan simplex communication. Sedangkan bila aliran informasi terdiri dari dua arah disebut duplex communication.

Gambar 1.3 Duplex Communication

3. Jenis Sinyal Elektrik

4. Optical Data Communication

Pada saat ini, salah satu yang dipilih untuk mengirimkan informasi sinyal digital adalah menggunakan media cahaya (optik). Sinyal-sinyal elektrikal dari rangkaian digital (tegangan tinggi/rendah) bisa dirobah menjadi sinyal-sinyal optic diskret (menyala atau tidak) dengan LED atau laser keadaan padat. Sinyal cahaya juga dapat diterjemahkan kembali kedalam bentuk listrik melalui penggunaan photo-diode atau photo-transistor untuk dimasukkan ke rangkaian gerbang.

Gambar 1.4 Pengiriman informasi melalui media cahaya

5. Network Topologi

Untuk menghubungkan peralatan digital yang bermacam-macam jenis dan banyak jumlahnya diperlukanlah sebuah jaringan. Bentuk-bentuk fisik dari jaringan inilah yang disebut dengan topologi jaringan.

6. Network Protocol

Pada topologi jaringan terdapat peralatan digital yang berfungsi untuk mengirimkan sinyal digital. Pengiriman sinyal antara peralatan yang satu dengan yang lain harus diatur agar tidak terjadi benturan sinyal. Network protocol mengatur hal ini sehingga proses pengiriman sinyal akan selalu terjaga kualitasnya.

7. Practical Consideration

Pertimbangan prinsipil untuk jaringan kontrol industrial, dimana pemantauan dan pengkontrolan proses-proses real-life yang harus berlangsung cepat dan sesuai, adalah waktu komunikasi yang sangat terjamin dari satu peraltan ke peralatan digital lainnya.

Pengertian PLC

noreply@blogger.com (Membahas tentang teknologi) — Fri, 15 Jul 2011 06:28:00 -0700

P = Programable

Adalah menunjukkan kemampuan dalam hal memori untuk menyimpan program yang telah dibuat yang dengan mudah diubah ubah fungsi dan kegunaannya.

PLC

L = Logic

Adalah menunjukkan kemampuan dalam memproses input secara aritmatik dan logic,yakni melakukan operasi membandingkan,menjumlahkan,mengalikan,mengurangi,dan/AND,atau/OR,perwaktuan//timer,penghitungan/counter dlsb.

C : Controller

Adalah menunjukkan kemampuan dalam mengontrol dan mengatur proses,sehingga menghasilkan keluaran/output yang diinginkan.

Menurut National Electrical Manufacturing Assosiation (NEMA),PLC didifinisikan suatu perangkat elektronik digital dengan memori yang dapat diprogram untuk menyimpan instruksi instruksi yang menjalankan fungsi fungsi spesifik seperti :logika,sequen,timing,counting dan aritmatika,untuk mengontrolsuatu mesin industri atau proses industri sesuai dengan yang diinginkan.PLC mampu mengerjakan suatu proses terus menerus sesuai variable masukan dan memberikan keputusan sesuai keinginan pemrograman,sehingga nilai keluaran/output tetap terkontrol.

Menurut Forum Sains.Com PLC merupakan”Komputer khusus”untuk aplikasi dalam industri untuk memonitor proses dan untuk menggantikan Hard Wiring Control dan memiliki bahasa pemrograman sendiri.Akan tetapi PLC berbeda dengan perangkat computer,karena PLC dirancang untuk instalasi dan perawatan oleh tehnisi dan ahli listrik di industri yang tidak harus mempunyai kemampuan elektronika tinggi dan memberikan kendali yang fleksible berdasarkan eksekusi instruksi logika.

Menurut CAPIEL 1982,PLC adalah system electronic yang beroperasi secara digital dan didesain untuk pemakaian di lingkungan industri,dimana system ini menggunakan memori yang dapat diprogram untuk penyimpanan secara internal instruksi instruksi yang mengimplementasikan fungsi fungsi spesifik seperti logika,urutan,perwaktuan,pencacahan dan operasi aritmatik untuk mengontrol mesin atau proses melalui modul modul I/O digital maupun analog.

Tank level Sensor With PLC

noreply@blogger.com (Membahas tentang teknologi) — Mon, 27 Jun 2011 21:52:00 -0700

Where can an instrument access the tank?  top, bottom, low on the side?  Access and/or mounting is a major consideration

- Ultrasonic or radar: non-contact, top mounted.  Ultrasonic has a dead zone at some distance ( <12") beneath face of the transducer where it can't read the echo signal.   I've heard that technically, level-radar is supposed to be used in metal tanks by some federal regulation or other, but the level-radar police do not appear to have been very active.  If you're next door to an airport they might be, though.

- submersible head pressure: pressure transmitter on a long cable with a vent tube attached for atmospheric reference is dropped into the tank from the top

- bubbler: top mounted; a tube with a v notch in the bottom that bleeds air bubbles from a differential air regulator. The back pressure in the tube equals the head pressure of the column of water.   Requires continuous stream of dry air.

- capacitance: a rod inserted from the top measures level due to capacitance of water.   Plastic tanks require a metal reference rod as part of the inserted rod assembly.

- pressure transmitter: plumbed to an access port near the bottom of the tank, reads the head pressure above the elevation of the access port (assuming transmitter is at same elevation as the access port)

- bypass sight gauge: plumbs to bottom or low side of tank.  Magnetic float flips a series of visual indicator flags.   All vendors offer some sort of optional electronic gizmo for creating a 4-20mA signal.

- level by weight
load cells weigh the tank and its contents, electronics subtract out the weight of the tank, leaving the weight of the water.  Those never-tiring electronic gnomes do some arithmetic on tank dimensions to create a level value.

From

About Software Avr Studio

noreply@blogger.com (Membahas tentang teknologi) — Tue, 29 Mar 2011 07:33:00 -0700

AVR Studio is an Integrated Development Environment (IDE) for writing and debugging AVR applications in Windows 9x/Me/NT/2000/XP environments. AVR Studio provides a project management tool, source file editor, chip simulator and In-circuit emulator interface for the powerful AVR 8-bit RISC family of microcontrollers.
In addition, AVR Studio supports the STK500 development board, which allows programming of all AVR devices, and the new JTAG on-chip emulator.
AVR Studio 4 has a completely new modular architecture which allows even more interaction with 3rd party software vendors. GUI plug-ins and other modules can be written and hooked to the system. Please contact us if you are interested in more information about this.

Gesture-controlled computers and robotic nurses being developed for operating rooms

noreply@blogger.com (Membahas tentang teknologi) — Tue, 22 Feb 2011 05:14:00 -0800

lthough surgeons need to frequently review medical images and records during surgery, they’re also in the difficult position of not being able to touch non-sterile objects such as keyboards, computer mice or touchscreens. Stepping away from the operating table to check a computer also adds time to a procedure. Researchers from Indiana’s Purdue University are addressing this situation by developing gesture-recognition systems for computers, so that surgeons can navigate through and manipulate screen content simply by moving their hands in the air. The system could additionally be used with robotic scrub nurses, also being developed at Purdue, to let the devices know what instruments the surgeon wants handed to them.

The system incorporates a Microsoft Kinect camera (yes, from the gaming system) and specialized algorithms to recognize hand gestures as instructions.

“One challenge will be to develop the proper shapes of hand poses and the proper hand trajectory movements to reflect and express certain medical functions,” said Juan Pablo Wachs, an assistant professor of industrial engineering. “You want to use intuitive and natural gestures for the surgeon, to express medical image navigation activities, but you also need to consider cultural and physical differences between surgeons. They may have different preferences regarding what gestures they may want to use.”

There are also other considerations that the researchers are taking into account in the design of the system. For instance, they don’t want surgeons to be required to wear special types of gloves or colors of clothing in order for their hands to be “read.” The system should also be able to recognize and respond to gestures quickly, and provide confirmation that it understands the request. At the same time, however, it should not accidentally respond to extraneous gestures, such as those made to colleagues in the room.

The Purdue team also want the system to be relatively inexpensive, and to be quickly and easily adaptable to different operating rooms, lighting conditions, and other variables.

The system could be particularly effective when combined with the robotic scrub nurses, although they wouldn’t be intended to replace human nurses in all situations. “While it will be very difficult using a robot to achieve the same level of performance as an experienced nurse who has been working with the same surgeon for years, often scrub nurses have had very limited experience with a particular surgeon, maximizing the chances for misunderstandings, delays and sometimes mistakes in the operating room,” Wachs said. “In that case, a robotic scrub nurse could be better.”

While other groups have also researched the use of robotic scrub nurses, Wachs claims that his is the first to look into the incorporation of gesture – instead of voice – recognition. The Purdue system is also apparently unique in that it uses advanced algorithms to predict where the surgeon’s hands will be next, or what screen images will next be requested.

From

Killzone 3 reviewed: PlayStation Move gets serious

noreply@blogger.com (Membahas tentang teknologi) — Mon, 21 Feb 2011 05:12:00 -0800

When I reviewed PlayStation Move last year, I named Killzone 3 as one of the games that would show us whether Move controllers were destined to gather dust in the cupboard or play an important role in the longevity of the PlayStation 3 platform. It is unquestionably the latter.

I've been playing first-person shooters for nearly 20 years, and I've played them with just about every possible input device along the way. I'm not going to say Move is better than a mouse and keyboard, but as far as consoles go, Move is by far the best controller yet...and turns Killzone 3 from a fantastic first-person shooter to the most immersive, visceral experience you'll find on a console today.

I gave Killzone 2 a 95/100 score back in 2009, and a vast majority of what I said in that review applies to the sequel, so I won't bother repeating it here. There's a couple of new (and very cool) weapons, more killer vehicle and fixed weapon sections, the best David vs Goliath boss fight I can remember (which introduces one of those new weapons very well), splitscreen co-operative, and thousands more bad guys to shoot. What more do you need?

The obligatory "I might be gushing but this isn't a perfect game" bit: there's some weird and very frustrating spikes in difficulty (if you don't like dying a lot, don't choose "normal" difficulty), including a confusing level that establishes itself as a stealth level, but then doesn't give you any indication when you get to the bit where stealth isn't going to work anymore. There are also enemies that can kill you in one hit (an FPS faux pas in my books), and you'll see plenty of them. The frequent cinematics are sullied by the fact that many characters and a majority of the dialog are cliched beyond belief. All relatively inconsequential scuff marks on an otherwise very polished game.

Killzone 3 is the kind of game that will sell both Move controllers and PlayStation 3 systems. Unquestionably a must-have title for PlayStation 3 owners even if you don't have Move (though you'd be mad not to grab a single player Move setup at the same time).

EGO-Kits give downhill mountain bikes a boost

noreply@blogger.com (Membahas tentang teknologi) — Sat, 19 Feb 2011 23:11:00 -0800

While electric commuting bikes are currently experiencing a surge in popularity, electric mountain bikes such as the Conway E-Rider and the KTM eGnition are also showing up on tradeshow floors with increasing frequency. Most of these are designed as cross-country and/or trail bikes, with the idea that the motor can extend their range above the reaches of pure human power – of course, they might also appeal to couch potatoes who want all the fun of mountain biking, with a minimum of the exercise. The EGO-Kit, however, is an electric motor that can be added onto an existing downhill mountain bike, with the specific purpose of replacing a chair lift for getting bike and rider to the top of the mountain.

The high-torque brushless motor puts out 1200W of nominal power, and 2400W maximum. It’s fed by a 48V lithium-iron phosphate battery, that is carried in an included backpack. That battery charges in 1.5 hours, is good for 1,500 loading cycles, and provides a range of 40 kilometers (25 miles) – although that figure depends highly on the grade of the mountain that’s being climbed.

The motor mounts on the bottom of the down tube, near the bottom bracket. This midships low-center-of-gravity configuration is said to have little effect on the bike’s handling. Its output is determined via a control unit and throttle, mounted on the handlebar. All of the gear, excluding the rider-worn battery, has a combined weight of 4.4 kilograms (9.7 lbs).

The kit is reportedly compatible with about 70 percent of downhill mountain bikes currently on the market. Riders can choose between completely forgoing the motor, using it to assist their pedaling, or using it on its own. At maximum output, it can manage a top speed of 70 kph (43 mph). It is also said to be able to handle inclines of up to 80 percent, although that depends on rider skills, motor temperature and soil conditions.

The EGO-Kit can be purchased through the company website for EUR1,870 (about US$2,520), plus shipping from Germany. A 500W version is also available for EUR1,650($2,225). Sales are slated to begin on April 1st ... no joking.

From

Rangkaian PLL (Phase-Locked Loop)

noreply@blogger.com (Membahas tentang teknologi) — Mon, 6 Dec 2010 23:35:00 -0800

Pratikum dasar telekominkasi banyak memakai rangkaian PLL.

Apa itu rangkaian PLL ?
PLL kependekan dari 'Phase-Locked Loop' pada dasarnya adalah sebuah sistem kontrol frekuensi yang memanfaatkan sensitivitas deteksi fasa antara sinyal input dan output dari sebuah rangkaian osilasi yang terkontrol.tikum

rangkaian ini banyak dipakai dalam pratikum dasar telekomunkasi hal ini cukup membuat saya tertantang dengan alat ini. walaupun hanya sekedar simulasi sinyal yang akan di cobakan. Tetapi cukup mewakili teori yang diajarkan didalam kelas.

Rangakain ini terdiri dari VCO
Rangkaian VCO akan terus berosilasi menghasilkan frekuensi f2 sampai f2 = f1. Ketika f2 = f1, maka tegangan Vdc keluaran rangkaian phase detector = 0 dan ini menyebabkan rangkaian VCO berhenti berosilasi (locked). Karena rangkaian loop ini akan mengunci (Locked) saat frekuensi dan fasa dari kedua sinyal sama, maka rangkaian ini disebut dengan Phase-Locked Loop.

Dual Regulated Power Supply High Current

noreply@blogger.com (Membahas tentang teknologi) — Fri, 26 Nov 2010 15:25:00 -0800

The circuit given here is of a regulated dual power supply that provides +12V and -12V from the AC mains. A power supply like this is a very essential tool on the work bench of an electronic hobbyist.
The transformer T1 steps down the AC mains voltage and diodes D1, D2, D3 and D4 does the job of rectification. Capacitors C1 and C2 does the job of filtering.C3, C4, C7and C8 are decoupling capacitors. IC 7812 and 7912 are used for the purpose of voltage regulation in which the former is a positive 12V regulator and later is a negative 12V regulator. The output of 7812 will be +12V and that of 7912 will be -12V.

circuit Dual Regulated Power Supply High Current

Free Switch Mode Pre-Regulator

noreply@blogger.com (Membahas tentang teknologi) — Thu, 25 Nov 2010 15:22:00 -0800

The botheration was that a voltage regulator had to bead the 18 volt capital ability accumulation voltage to 8 volts at 500ma to ability the CD player, crumbling 5 watts of ability and causing a lot of calefaction central the bunched unit. This ambit acts as an interference-free pre-regulator to abundantly abate the ability loss..

The achievement voltage of this ambit is artless by ability band fluctuations. Amount voltage aberration is alone abased on the on-resistance of Q2 and the amount of C2 (re: ripple). The achievement voltage can be set so that the ripple lulls are aloof aloft the drop-out voltage of the beeline regulator at best amount for best activity conservation. The college amount you aces for C2, the added activity you can save and the added abiding the pre-regulator’s achievement voltage.

circuit Free Switch Mode Pre-Regulator

78XX Family Regulators Universal PCB for PSU

noreply@blogger.com (Membahas tentang teknologi) — Wed, 24 Nov 2010 15:18:00 -0800

Many DIY projects require a small Power Supply.
The 78XX family is ideally suited for this job, and with this little PCB you can easily build small Power Supplies for virtually every application.
The circuit is very simple:
The Alternating current is applied to X1 and rectifies by B1.

It charges a large Capacitor C1 to power the regulator.
The output voltage depends on the Regulator you use, e.g. 7805, 7812,7815…
Dimensionierung:
C1:4700u, with sufficient voltage Rating!
C2:0.33u
C3:0.1u
The Heatsink should be enough for devices with moderate power consumption.

RS-232 Reset for Microprocessor

noreply@blogger.com (Membahas tentang teknologi) — Mon, 22 Nov 2010 15:03:00 -0800

Introduction
This circuit allows a remote microprocessor to be reset by a controlling host by sending a break signal over an RS-232 or RS-422 serial line. If the remote machine resets into a simple program loader program, it is possible for the host to halt and restart, or halt and reload/restart the remote machine’s program. This is an ideal way to develop software on older EPROM-based systems. Modern EEPROM/NVRAM systems use JTAG interfaces for similar results.

The remote processor runs its target code out of RAM, allowing the code to be updated easily. The circuit is usually used for developing code on a target processor, but it can also be used for permanent applications where the target program lives on a host system’s disk. This system was once used to load code into a microprocessor-based satellite receiving system in Hawaii from a host system in Colorado using an Internet-based remote serial communications program.

A program loader for the Z80 CPU is available below. The circuit has also been used with the Motorola 68HC11 EVB and the BUFFALO monitor program. See my Linux Cross Assemblers page for more info.

Theory
This circuit detects long duration zero level signals (breaks) on a NRZ (non return to zero) serial data line. Normal serial characters spend a short time in the zero state, and do not cause a reset. Break signals are a exception to this, they hold the line low for an extended period.

The 10K/1N4148 parts keep the 2.2uF capacitor charged up. Low input signals go through the 10K resistor and slowly pull the charge on the 2.2uF capacitor down. High input signals quickly recharge the capacitor through the 1N4148 diode. A break signal lasts long enough to discharge the 2.2uF capacitor to the point where the following gate changes state.

The 1N4148 on the right allows a manual break switch to be used on the target CPU, pressing such a switch does not short out the preceding 74HC14 gate.

This circuit could be built with just 2 schmidt trigger non inverting buffers, the 74HC14 was chosen because it is a common part. The parallel inverters are also optional, single inverters work fine.

Z80 Program Loader
Here is a Z80 assembly language program that functions as a bootstrap loader for use with the Microprocessor RS-232 Reset circuit. This code runs on an ancient SD systems SBC200 Z80 circuit board and can be made to work with other Z80 boards by changing the initialization and serial port functions.

Keyboard Given Bluetooth Hardware by I-O

noreply@blogger.com (Membahas tentang teknologi) — Mon, 8 Nov 2010 16:59:00 -0800

At present many PDA come equipped of one, not always comfortable one, keyboard hardware. And like making for those devices that they are unprovided some? I have thought Given to us that he has recently announced a new keyboard bluetooth. Keyboards wireless for dis positive furniture's us of are many in turn, but the no pretty, light and thin like this Unfortunately characteristics, the prices and the availabilities are not still notes with precision, it knows that the keyboard is equipped with a receiver compatible Bluetooth 2,0 + EDR with all cellular Pocket PC and. From the photos moreover it is possible to notice that the layout of the keyboard he is compatible with the Italian and therefore the writing, at least for we, turns out much comfortable one. We will be to see when it will arrive and to that price.

Voice Broadcaster

noreply@blogger.com (Membahas tentang teknologi) — Tue, 2 Nov 2010 16:48:00 -0700

This voice transmitter is a short range transmitter which has a 15 meters range without an antenna,and this can be increased several times over if an antenna is used.The circuit can accept inputs from music systems,high impedance microphones and any amplifier.

A single AC188 pnp transistor handles modulation.RF amplification and transmission.The 3 volt transformer used to boost the input level and provide higher impedance when a low impedance source is used.The circuit works off a 6 volt battery.

VCR and the position of the MW antenna coil(used in pocket receivers) must be adjusted to obtain the best output from the unit on a receiver tuned to a dead spot on the MW band,placed a few meters away.Batteries should be used in preference to adapters and these would give a considerably long life as the consumption is quite low.

The Schematic Voice Broadcaster

Water Level Monitor

noreply@blogger.com (Membahas tentang teknologi) — Tue, 2 Nov 2010 08:42:00 -0700

This single chip based CMOS circuit can detect water levels in a water tank,pool,channel etc,. and display on an easy to interpret is level display. In case the level exceeds a certain level ,the circuit can sound ana alarm (optional).Built around a single CMOS hex inverter ,this circuit lends portability as well.

CD4049 forms the heart of the circuit.When water crosses a certain level, it bridges sensor Sc (common) and S1 through S6 This water resistance, being less than that due to R1 through R6, the outputs go high and the corresponding LED is activated.The piezo buzzer is optional.Normally a small 20 mm piezo won't warm up to the IC but if a bigger one is used, a 100 ohm series resistor should be inserted.

The Schematic Water Level Monitor

The sensor is made as shown in figure a.The sensor has a plastic or PVC rod of the height of the tank etc and has metallic rings fixed at equal spaces,The connection are made using ribbon cables.

Figure a

The Finished devise can given a panel shown in figure b.This panel may either be photo copied on to film or used directly.The sensors can be fixed on one side of the water whose level is to be measured.

figure b

Austere Ni-Cad Cell Charger

noreply@blogger.com (Membahas tentang teknologi) — Mon, 1 Nov 2010 20:23:00 -0700

This simple,low cost ni-cad cell charger can charger up to two AA or C sized cells at one time at the standard rate of 40 mA.The unique feature of this charger is its extremely compact size and transformer less design(unlike others),hence ending up in the form of a neat and compact little module.There is provision for mounting the cells to be charged within the PCB (hence no external wiring is needed ,thus eliminating chance of failures due to snapping of wires etc).This enhances the utility all the more as the charger can then be used as a rechargeable power pack that can be used to replace the original battery holders in equipment such ac pocket radio etc.to make them rechargeable.The circuit employs the PCR (periodic current reversal) method of charging which increases cell life
.
R1 is used as a surge protector.C1 works as a series dropper.The dropped voltage is rectified and converted into DC by diodes D1 through D4.C2 provides the necessary filtration.The final voltage is applied to the cells for charging.R4 through R7 generate the PCR effect by allowing current in direction opposite to the diodes to pass in minute proportion,it may create the effect just the opposite that desired,These resistors may be simply left out if the normal charging procedure is to adopted.

The Schematic Austere Ni-Cad Cell Charger

As C1 may be charged to fatally high voltage, an 820 kohm shunt resistor is used to discharge it when the power is turned off.The LED D5 along with R2 provide pilot indication as well as a"don't touch warning indication.

The Pocket Receiver

noreply@blogger.com (Membahas tentang teknologi) — Wed, 20 Oct 2010 17:30:00 -0700

Not that there is any paucity of pocket receivers or that they are too expensive,or that there are hardly any well known circuit that we decided to design' another one'. It's not just another one.

The True Pocket Receiver
No doubt, dozens of models are commercially available but they aren't truly pocket sized (rather pocket oversized ). Not many,leave alone the corner of a shirt pocket, fit into a normal shirt pocket leaving enough space to even tack a wallet, Well that's the reason we thought of designing a pocket receiver small enough to fit into a shirt pocket or clip on to a belt that is - a pocket receiver in the true sense. And that exactly is what we have here !

How it Works?
The circuit is given in picture.It uses an 8-pin DIP ZN415 radio receiver chip from Ferranti. The circuit has an edge over the ZN414 in having an in-built amplifier stage. The IC contains a complete AM detector subsystem. The circuit uses a tuned circuit based on L1 and VC1 serves as tuning control.L1 detects the signals and passe them on to IC1, which in turn, drives high impedance headphones. That's all.

The IC thus allows construction of a light weight,low voltage and quality receiver.

The Solar-Powered Robotic Automower

noreply@blogger.com (Membahas tentang teknologi) — Wed, 13 Oct 2010 22:33:00 -0700

As you look over your neighbor’s lush, green lawns, remember that his garden didn’t turn out that way overnight. So stop turning green with envy and start working on your own yard by using the solar-powered automower.
This great technology advancement looks nothing like an ordinary mower. And indeed, it isn’t. The solar-powered automower is specially designed to keep your pre-wired green lawn short and trim to perfection. You can also use this device to lay the wire around plants and flower beds. Not only that. You can also go eco-friendly with this device as it is 100% solar-powered.
The solar-powered automower comes with safety features to protect your kids and your pets. The retail price for this is set at $3,100.

Being the worlds first fully automatic, robotic lawn mower, the Auto Mower is the ultimate user friendly mower. You don’t have to lift a finger to get a perfect lawn.
Before the Automower can get to work, you will need to simply staple a wire to the perimeter of the lawn. The wire will be overgrown and become invisible within a month. This wire can be sensed by the robotic mower and will ensure that only this area of grass is cut. The Automower will then work irregularly around the lawn – whatever its shape – until all parts have been covered. This gives the lawn an even result and a carpet-like finish. ‘Islands’ can be created by laying the wire around plants and flower beds. And if the mower hits any other obstacle, such as a tree or rock, it just reverses safely and selects a new direction before continuing.
The Automower comes with an automatic charging station. Once placed in a suitable position in the garden, this will keep its maintenance-free battery charged at all times. Besides the low running costs (around 12-25 dollars a year for the electricity consumed, depending on lawn size), the mower is so quiet that it won’t disturb your neighbours. And with no emissions, it is environmentally friendly.

BlackBerry : native push notifications

noreply@blogger.com (Membahas tentang teknologi) — Mon, 11 Oct 2010 19:52:00 -0700

Today we’re launching the most requested feature for BlackBerry: native push notifications. Now, after you download the new version of foursquare (v 1.9.5), you will know instantly when your friends check in. With BlackBerry native push notifications, no more getting an update 20 minutes late, or having to leave foursquare running in the background

What is the BlackBerry Push Service?
More than just an alert! The BlackBerry Push Service allows an application to give the user immediate access to information that no other platform can provide in quite the same way. The BlackBerry user sees a notification appear, letting them know that one of their applications has new information for them. They can quickly go to that app (without having to shut down anything they are currently doing) and the new information is right there. Users don't have to open the app and download the new information, the new content has already been pushed (BlackBerry developers can push up to 8KB of content in each push).
It's not a notification that tells you to go get information, it brings you the information. Other platforms flip the flag up on the mailbox, letting you know it's time to go to the end of the driveway and get your mail. BlackBerry Push delivers the mail to your kitchen table, open and ready to be read.
But wait. There's more…
Applications leveraging BlackBerry Push Service don't have to compete with other applications that are receiving pushes. One application's latest push won't trump another application's existing push – users won't miss their chance to see all the latest information available to them.

What is being made available today?
The BlackBerry Push Service has two options: BlackBerry Push Essentials is a free service that developers can incorporate into their applications and allows them to push content to their customers with unparalleled immediacy. BlackBerry Push Plus which has a free tier and paid tiers, provides developers with notification that their push has been delivered. If a content provider needs to get information to someone, they can tell if the target device has received the push.

BlackBerry Micro-USB Car Charger

noreply@blogger.com (Membahas tentang teknologi) — Sat, 9 Oct 2010 17:12:00 -0700

When you're on the road, a fully charged BlackBerry device is more than a convenience - it's a necessity.
Now it's easier than ever to keep your device fully charged, wherever that road takes you. Just plug the BlackBerry Vehicle Power Charger into your car's power adapter (the "cigarette lighter") and it reliably delivers constant current and voltage to charge your device safely and rapidly.
The micro-USB charger comes with a coiled cord that stretches up to 6 feet (2 meters) for your convenience

The input/output (i/o) ports in CPU

noreply@blogger.com (Membahas tentang teknologi) — Sun, 3 Oct 2010 08:08:00 -0700

Computer I/O (input/output) port allow the CPU to control devices in the outside world.Signals may be output to control lights,motors and heaters for example. Conversely,signal from the outside world,provided by sensors such as simple switch,thermistors,opto diodes (light sensors) and pressure sensitive devices, may be input to the CPU.These signals can be analyzed and processed, with the CPU outputting new signal in consequence.So like sea ports along the coast which allow goods to be brought into and out of a country,I/O port allow signals to pass into and out of a computer.

The word 'signal' in this context is meant to imply an electrical or electronic value,or variation in value,which carries information.Signals have no power they only carry information.You can't simply connect devices to the ports and expect them to work.Obviously (at least I hope it's obvious) you can't connect ordinary,mains light bulbs to output ports .A 60W main lamp needs 240V at 250mA ; the output ports of 6502 and Z80 systems can only manage a maximum voltage of 5V, at a current some hundred times less than the 250mA quoted for the lamp.The signals could not even light up a small LED but they can be amplified of course.

The television signals appearing at the end oh the aerial cable are of the order of microvolt and they can't drive anything either.But all the complex information about the sound,vision and color,together with synchronizing
pulses and teletext,are carried in the signal.It has only to be processed and amplified by the television receiver.

Turning the low voltage,low current computer signals into something which can drive light,motors or heaters requires 'interfacing'.The interface is an electronic block which accept low level signals,and condition them so that they are suitable in amplitude(both voltage and current)for driving the peripheral to which the interface is connected.

Digital Computers

noreply@blogger.com (Membahas tentang teknologi) — Sat, 25 Sep 2010 16:39:00 -0700

Modern computers are digital computers.Digital systems operate in a limited number of finite states,usually only two,as is the case with digital computers. Let us considers again precisely what is meant by digital. Take the example of clock used to tell the time.(A new meaning of"clock" will be introduced later).

An analog computer of the late 1950’s.
Those machines were more powerful than digital computers for applications requiring modest accuracy, and IMACS (then still AICA) played an important role in the introduction   of this computing tool in the industrial world , playing an important role in the   beginnings of computer simulation in industrial and scientific development. E.g. they were essential to the US Space program of the 1960s, and held an important place in   the study of the safety of the many nuclear power plants   built in Europe in the post WW II years.

The beginnings of IMACS date from 1955, when an International Conference on Analog Computation was held at the Brussels Free University (ULB) , attended by scientists and managers of simulation laboratories from different parts of the world. Many of these laboratories were byproducts of the enormous technological developments that had been brought about by World War II. The participation was truly international, with attendees coming from most European countries including Russia, the United States of America, Japan.

    During the conference, it was realized that there was a need for establishing some permanent means of communication between the members of this new scientific community. What resulted was the creation of AICA (the International Association for Analogue Computation) which was legally incorporated under the Belgian Law in 1956.

    The birth of AICA illustrated the emergence, at the time, of disciplines spurred by new technologies, in particular those resulting in tools having to do with the mechanization of information and computation. The example was followed in short order by the formation of other organizations in particular fields of applications, namely IFAC (Automatic Control, 1957) , IFORS (Operations Research- 1959), IMEKO (Measurement - 1959) and IFIP (Information Processing- 1960).

    In 1972, these five organizations decided to coordinate their activities with the creation of FIACC (the Five International Associations Coordinating Committee), which was created with the support of UNESCO.

   It had been under Jean Hoffmann, Professor at the Brussels Free University (ULB) that the 1955 International Conference on Analog Computation that gave birth to AICA was organized. He became President of the newborn association, a post he held until 1973.

    The objectives of AICA remained pretty much unchanged during that period, objectives related to analog computation developed as a tool for applications to mostly industrial problems. This included hardware questions, mathematical and programming aspects with some consideration, beginning in the mid-1960's, to what had emerged as hybrid computing, i.e. computing involving linked analog and digital machines.

About IMACS

Hoffmann was succeeded by Professor Robert Vichnevetsky who was elected President at the Association's 7th World Congress in Prague, August 1973. It was during Vichnevetsky's tenure that the Association grew, leading to the visibility it holds today in scientific computing and applied mathematics. Significant developments were taking place in the sciences at the time and the scope of what was still known as AICA began to expand to include numerical computing, subdisciplines in applied mathematics, and the introduction of mathematical modeling in many of the traditional fields of the applied sciences that had to change their ways to keep up with the new environment. In 1976, AICA changed its name to IMACS (International Association for Mathematics and Computers in Simulation) to reflect the widening of its areas of interests.

   IMACS also expanded its administrative structure, its international coverage with legal incorporations and offices in both the USA and Belgium and affiliated societies in other parts of the world - as far as China, Japan and Australia/New Zealand. (which, in a way, illustrates the fact that the globalization of science preceded the globalization of industry - something that remains true in following years).