خواب چه تصمیمهاى روزانه را که نقش بر آب کرد . [نهج البلاغه]

tecnologycontorol

Sziklai Output

چهارشنبه 89 فروردین 25 , ساعت 10:40 صبح

The Complementary Sziklai Output

Named after a prolific inventor by the name of George C. Sziklai, this version sports a Sziklai output section, or what is sometimes called the "Complementary Feedback Pair".

What is a Sziklai?
In essence, a high gain super transistor, somewhat similar to a Darlington. But there are major differences. Unlike Darlingtons, there is some voltage gain with Sziklais. Another unique feature is local feedback.

Why is it not as popular as EF?
Basically, more difficult to design then EF. When local feedback is nested in a global feedback, an amplifier is more prone to instability. In other words, it is easier to break out into high frequency oscillations. But a well designed Sziklai Output can often be outstanding.

Performance Factor
This is where it probably makes a real difference. With listening tests, the Sziklai Outputs are the most enjoyable of the three designs. It sounds faster and the highs are smoother. This is probably due to a wider bandwidth and faster rise time. All these are achieved without compromising bass slam and definition. Clip characteristics are similar to c200 (EF version), with no signs of distortion and instability when driving 8 and 4 ohms test loads up to rated power.

Mr George Clifford Sziklai is credited for inventing the full complementary symmetrical output that we take so much for granted today. More information on his illustrious career can be found at this Los Altos Town Crier article by writer Linda Taaffe.

THD of c200.2 complementary Sziklai output

Biasing of output transistors
All THD readings were done with outputs biased to 12mV across 0.22 ohms emitter resistor. This works out to approximately 55mA per output transistor in idling state

نوشته شده توسط mehrannemati | نظرات دیگران [ نظر]

Download

یکشنبه 89 فروردین 22 , ساعت 9:56 عصر

First, in order to enable the download menu commands, you must select the Block folder in the project"s station you wish to download.

There are three methods of downloading.

Partial download of selected blocks
Full download of all blocks and system data
Complete deletion of online PLC blocks and then downloading of all blocks and system data

Partial Download

Partial downloads are used in existing projects where only one or more blocks will be downloaded. To perform this type of download select the block(s) you wish to download and then select the PLC > Download menu item or the download button .

Holding down the Ctrl key or the Shift key allows more then one block to be selected at a time. Be careful though as the order of download will occur in the order that the blocks were selected. This may mean that an error will occur if a block is called before it is downloaded.

The CPU will need to be in Stop mode before downloading the System Data Block (SDB) as this is equivalent to a hardware configuration download. This is usually not necessary in a PLC that has all ready had its hardware configured. If you do download the system data, the following messages will prompt you through the transitions.

If the CPU is in Run mode then you will be prompted to Stop the CPU. The software will do the Run to Stop transition when you click OK.

After downloading the SDB you will be prompted to Run the CPU again.

Clicking Yes will automatically put the CPU back into run mode.

Full Download

To download all the blocks at once make sure you are in the Block folder and select the Edit > Select All menu item. Click on the Download icon . You will be prompted to overwrite any existing blocks and if you want to load the system data (see above).

Clearing the CPU Memory and then Downloading

The partial and full download methods above will overwrite existing blocks but will not any blocks from memory. In order to completely delete the existing program in the CPU and download a new project select the Blocks folder and then use the PLC > Download User Program to Memory Card menu item.

The following dialog box will pop up prompting you about the deletion of all the blocks and project data in the PLC. Click Yes to perform the operation.

After this, follow the normal download procedure.

‹ Connecting to the S7 PLC up Uploading ›

نوشته شده توسط mehrannemati | نظرات دیگران [ نظر]

plcUploading

شنبه 89 فروردین 21 , ساعت 2:10 عصر

Step 7 Connecting, Downloading and Uploading

These are general guidelines for connecting, downloading and uploading from an S7-300 or S7-400 PLC. The following procedures were created using Siemens SIMATIC STEP 7 version 5.4 software.

To start, open the SIMATIC Manager.

Now follow the links below.

نوشته شده توسط mehrannemati | نظرات دیگران [ نظر]

Pico Controllers I/O

جمعه 89 فروردین 20 , ساعت 2:3 عصر

<> if (eW3C==true) eClose("Programmable Automation Controllers (PAC)");
if (eW3C==true) eOpen("Programmable Logic Controllers (PLC)");
if (eW3C==true) eClose("Safety Programmable Controllers"); Pico Controllers I/O

Programmable Logic Controllers

Pico Controllers

I/O

You may have several different types of applications where the Pico controllers can be used. The Pico expansion I/O modules provide you with flexible choices that allow you to purchase the I/O count you need for a variety of applications. It is simple for you to expand the 18- and 20-point and GFX processors with any one of the Pico expansion I/O modules. Select between 2- or 6-point AC Relay outputs and the 8-point DC transistor outputs modules that you can use with AC or DC processors.

Pico GFX controllers are expandable up to 272 I/O points with the use of the current Pico expansion I/O modules and Pico-Link. Connect up to eight GFX controllers using the new GFX proprietary Pico-Link inter-connectivity network. It provides you more points of I/O and allows you to peer into the process.

نوشته شده توسط mehrannemati | نظرات دیگران [ نظر]

Pico Controllers

جمعه 89 فروردین 20 , ساعت 1:58 عصر

Programmable Logic Controllers

Pico Controllers

Pico Controller

The Allen-Bradley Pico controller performs simple logic, timing, counting, and real-time clock operations. Splitting the difference between a timing relay and a low-end PLC, the Pico controller is ideal for relay replacement applications, simple control applications such as building and parking lot lighting, and applications in which cost is a primary issue. Designed with ease of use in mind, all programming and data adjustments can be done via the on-board keypad and LCD display, or with PicoSoft™ configuration software.

Available as 120V/240V ac, 24V ac, as well as 12V and 24V dc versions
Dc and analog inputs
Up to 38 I/O points when an I/O expansion module is connected to an 18-point controller
EEPROM memory
Password security
Simple math
Real-time clock
Text display
PicoSoft programming software
UL, CSA, or C-UL CE

Pico Series B — Replaces Series A

The Pico Series B controllers are equipped with faster processor speeds and an expanded memory, resulting in three times the ladder logic capacity and twice the number of function blocks than previously available. The new line of controllers also features backwards-compatible programming, improved display functionality and additional power supply options. The Pico Series B line of controllers includes an increased retentive memory range, enabling the controllers to be used in applications that require up to 128 lines of ladder logic. The controllers also have additional coil functions, and enhanced clock and seasonal time configurations.

14 NEW and 9 updated controllers with: