Green Economy

There are two important international summits,G-20 and Rio +20,starting from 18th June and 20th June at Mexico and Rio De Janeiro respectively.The seventh G-20 summit of developed and developing nations will be mostly dominated by Euro Crisis and its effect on world economy.Also the slowing growth in India and China,a major concern for world economy,will be a major point.While Rio + 20 summit is a totally different summit from G-20 summit.This summit is being held after 20 years of Earth summit.The main discussion/objective of this summit will be 'Green economy in the context of sustainable development and poverty eradication'.

Green Economy:

Green Economy is an initiative by UNEP (United Nations Environment Programme) started in late 2008. UNEP has defined the Green Economy as one that results in improved human well-being and social equity, while significantly reducing environmental risks and ecological scarcities. In its simplest expression, a green economy can be thought of as one which is low carbon, resource efficient and socially inclusive.

Practically speaking, a green economy is one whose growth in income and employment is driven by public and private investments that reduce carbon emissions and pollution, enhance energy and resource efficiency, and prevent the loss of biodiversity and ecosystem services. These investments need to be catalyzed and supported by targeted public expenditure, policy reforms and regulation changes. This development path should maintain, enhance and, where necessary, rebuild natural capital as a critical economic asset and source of public benefits, especially for poor people whose livelihoods and security depend strongly on nature.


Green Economy Initiative:

The UNEP-led Green Economy Initiative, launched in late 2008, consists of several components whose collective overall objective is to provide the analysis and policy support for investing in green sectors and in greening environmental unfriendly sectors.

Within UNEP, the Green Economy Initiative includes three sets of activities:
1. Producing a Green Economy Report and related research materials, which will analyse the macroeconomic, sustainability, and poverty reduction implications of green investment in a range of sectors from renewable energy to sustainable agriculture and providing guidance on policies that can catalyze increased investment in these sectors.
2. Providing advisory services on ways to move towards a green economy in specific countries.
3. Engaging a wide range of research, non-governmental organizations, business and UN partners in implementing the Green Economy Initiative.

For all the details you can visit UNEP website: 
http://www.unep.org/greeneconomy/

Linked Switch in Power System

A linked switch is nothing but double pole or three pole switch (mechanical) to break/make the circuit.Mostly you will see this while operating Electrical hoists,pump motor starter etc.Almost in every circuit it is present.

fig. different switches

Rafael Nadal Clinches record 7th French Open title...

Rafael Nadal shook off the anxiety of a tense, wet evening in Paris just in time to defeat the world’s top-ranked tennis player and make French Open history.

Rafa beat Novak Djokovic as 6-4,6-3,2-6,7-5 to win his 7th French Open title and broke his tie with Bjorn Borg for the most men’s singles championships in tournament history.

PLC/Basics/02

PLC Components :-
            1) Power Supply Module

            2) CPU or Processor

            3) Communication Modules

            4) Data Modules (Input & Output Modules)   

Fig. PLC Components

The details of each module are -

1) Power Supply Modules

Fig. Allen-Bradley Power Supply Module with Chasis

        Power supply module supplies power (DC) to the all other modules (CPU/Processor,Communication Modules,Data Modules,etc.). Every Logix Platform has it's type of Power Supply Module.

e.g. AB ControlLogix has power supply module AB PA72,AB FlexLogix has AB Flex Power Supply Module,etc.

       PSU supplies power to all other modules through Chasis (Generally at 1.3V/3.3V/5V/24V DC).While input voltage to PSU is 110V/220V ac or 24V/48V DC. PSU rating is in amperes.

More information about Allen-Bradley Power Supply module available at

http://www.ab.com/en/epub/catalogs/12762/2181376/2416247/360807/1837526/print.html 

2) CPU or Processor

  

        CPU (Central Processing Unit) is the brain of PLC system. It runs all programs/processes/calculations /interlocks etc.

        
      


   

PLC/Basics/01

Q. What is PLC..??

        It is Programmable Logic Controller,  a Solid-state device with digital processing capabilities designed for Real-Time control of processes or a Digital computer used for Automation of Electromechanical Processes such as control of machinery on factory assembly lines.

 e.g. an induction motor,solenoid actuator,limit switch,ON/OFF or push buttons,etc.

Detailed Definition of a PLC : A programmable controller is a small industrial strength computer used to control real world actions, based on its program and real world sensors. The PLC replaces thousands of relays that were in older electrical panels, and allows the maintenance technician to change the way a machine works without having to do any wiring. The program is typically in ladder logic, which is similar to the wiring schematics maintenance electricians are already accustomed to working with. Inputs to a PLC can be switches, sensors, bar codes, machine operator data, etc. Outputs from the PLC can be motors, air solenoids, indicator lights, etc.

 

Q. Why PLC had been developed..??

        To replace the hard wired relay control in industrial process automation by electronic control.The basic idea was to replace very complicated,unreliable,difficult for up gradation,time consuming,difficult to implement,limited scope and slowly operating Hard Wired Relay Control by a simple or easy to implement or understand,general purpose,reliable,fast operating Electronic Control.

Q. History of PLC..??

         Demanded by GM Hydramatic and proposed by Bedford, Massachusetts in 1968.First PLC name 084.Bedford started new company for PLC called Modicon. Modicon brand acquired by Gould Electronics then by AEG and then by Schneider Electric.

Presently major players are Siemens,Allen-Bradley,Omron,Schneider,Mitsubishi,etc.

Q. How did the Ladder Logic Programming come..??

       1.  Earlier PLCs were developed to replace the relay control or relay logic. This program notation had been used to reduce/avoid the training required for existing technicians as Ladder logic resembles the relay logic.

      2. Modern PLCs can be programmed using Ladder logic or BASIC or C language or State Logic. But because of phenomenon of graphical representation of program logic, Ladder logic programming became common.

Q. How PLC programming is done..??

       PLCs are programmed using application/programming software on personal computers. The computer is connected to PLC through Ethernet,RS-232,RS-485 or RS-485 cabling.

 e.g. RSLogix 5000 is a software/platform for PLC Programming.

Rafa again wins Clay court Duel...

    Rafael Nadal again played superb on Clay court to equal Bjorn Borg's World record of six French open titles,defeating Roger Federer as 7-5, 7-6 (7/3), 5-7, 6-1 in three and half hour epic duel.

                    Rafa hits a backhand during epic duel with Roger at French Open.

Welcome to vishnu's blog..

Hiii...everybody.. welcome to my blog....