Series Diode Limiter Circuit

Manley ELOP Limiter $2970 Set it and forget it! The Manley Optical ELOP Limiter makes your job easy. The principle of operation is based around using a rectified sample of the audio to shine an LED (Light Emitting Diode) onto an LDR (Light Dependent Resistor). The photo-resistor in combination with a fixed resistor simply act as a changing voltage divider to attenuate the signal &mdash like a smart volume control. A similar principle was found in the older Teletronix & Urei LA-2A, LA-3, and LA-4 units, which used a slower electro-luminescent panel-light on a conventional LDR encased in a light-tight enclosure. The Manley ELOP Limiter uses modern VACTROL technology (but with a trick!) for exact sample-to-sample tracking and no high frequency loss while digging deep into limiting &mdash problems commonly associated with older LA-series limiters and other opto-based units. The audio signal passes only through Manley's super-clean single-ended vacuum tube line amplifier. Due to its inherently quick attack, this Electro-Optical Limiter is a skilled soldier for tracking vocals or individual instruments, although now with the addition of a very useful sidechain high-pass filter that can switch between 100Hz or 200Hz (or OUT) to allow the limiter to ignore heavy bass lines, the Manley ELOP limiter is proving more useful for modern urban music where you don't want the limiter only responding to the loudest "thing" i.e., the BIG bass. If you want the bass line to leave the rest of the mix alone, then this switch is for you!

Langevin Stereo Elop Limiter $1620 Set it and forget it! The Langevin Stereo-Optical ELOP Limiter makes your job easy. The principle of operation is based around using a rectified sample of the audio to shine an LED (Light Emitting Diode) onto an LDR (Light Dependent Resistor). The photo-resistor in combination with a fixed resistor simply act as a changing voltage divider to attenuate the signal &mdash like a smart volume control. A similar principle was found in the older Teletronix & Urei LA-2A, LA-3, and LA-4 units, which used a slower electro-luminescent panel-light on a conventional LDR encased in a light-tight enclosure. Manley uses modern VACTROL technology (but with a trick!) for exact sample-to-sample tracking and no high-frequency loss while digging deep into limiting &mdash problems commonly associated with older LA-series limiters and other opto-based units. The Langevin limiter's audio signal passes only through Manley's super-clean single-ended vacuum tube line amplifier. Each channel can be run separately or switched to "stereo &mdash link ". Due to its inherently quick attack, this Electro-Optical Limiter is a skilled soldier for tracking vocals or individual instruments, although now with the addition of a very useful sidechain high-pass filter that can switch between 100Hz or 200Hz (or OUT) to allow the limiter to ignore heavy bass lines, the ELOP limiter is proving more useful for modern urban music where you don't want the limiter only responding to the loudest "thing" i.e., the BIG bass. If you want the bass line to leave the rest of the mix alone, then this switch is for you! ALL-DISCRETE audio path Balanced XLR inputs & outputs Unbalanced 1/4" inputs & outputs Silent conductive plastic input attenuators Max. Gain reduction 22db Attack time: 10ms for 6db GR Release: 2.5 seconds for 6db GR BYPASS switches Sifam VU METERS Meters switch to read OUTPUT or REDUCTION STEREO LINK switch

Manley Elop Limiter $2970 Set it and forget it! The Manley Optical ELOP Limiter makes your job easy. The principle of operation is based around using a rectified sample of the audio to shine an LED (Light Emitting Diode) onto an LDR (Light Dependent Resistor). The photo-resistor in combination with a fixed resistor simply act as a changing voltage divider to attenuate the signal &mdash like a smart volume control. A similar principle was found in the older Teletronix & Urei LA-2A, LA-3, and LA-4 units, which used a slower electro-luminescent panel-light on a conventional LDR encased in a light-tight enclosure. The Manley ELOP Limiter uses modern VACTROL technology (but with a trick!) for exact sample-to-sample tracking and no high frequency loss while digging deep into limiting &mdash problems commonly associated with older LA-series limiters and other opto-based units. The audio signal passes only through Manley's super-clean single-ended vacuum tube line amplifier. Due to its inherently quick attack, this Electro-Optical Limiter is a skilled soldier for tracking vocals or individual instruments, although now with the addition of a very useful sidechain high-pass filter that can switch between 100Hz or 200Hz (or OUT) to allow the limiter to ignore heavy bass lines, the Manley ELOP limiter is proving more useful for modern urban music where you don't want the limiter only responding to the loudest "thing" i.e., the BIG bass. If you want the bass line to leave the rest of the mix alone, then this switch is for you!All-tube audio path 12au7wa + 6414 per ch.Unbalanced " inputs and outputs andBalanced transformer coupled XLR inputs and outputsHi-current drive

dbx 2215 Dual-Channel 15-Band Equalizer/Limiter $429.95 2215 Dual Channel 15-Band Equalizer/Limiter 20 Series EQs. You used to have to settle for second best in a reasonably priced EQ but not any more. With the 20 Series from dbx Professional Products you get a great EQ circuit, a graceful yet powerful limiter and the revolutionary new design of the Type III Noise Reduction.Dual-channel 15-bands 2/3-octave per band PeakPlus limiter LED bar graph for gain reduction and output level Status LEDs for all settings on the front panel XLR, barrier strip, and 1/4" connectors 45mm nylon sliders 12dB input gain stage

Radial Engineering Komit Compressor Limiter $499.99 The Radial Komit Compressor Limiter is one of the eight modules designed to be comprise the Radial Workhorse Rack and Mixer System that combines the popular 500 series platform with an incredibly flexible patching system to let you create the ultimate studio environment. The Radial Komit is a feature-rich compressor-limiter that simplifies the process of dynamic manipulation while expanding upon creative tone shaping. At one end is a super-clean compressor that delivers amazing results with single knob control. At the other, an old-school diode bridge clipping limiter goes from 'vintage to nasty'. But don't let the minimalist approach deter; the Komit provides exceptional flexibility by integrating a series of automatic functions that are both musical and intuitive.The design begins with an auto-detecting feed-forward VCA that reads the incoming program material and reacts 'real-time' to the time constant. Set the 3-position attack-decay switch to slow for vocals, medium for instruments and fast for percussion. As you increase the ratio, the Komit FlexKnee compression dynamically adjusts the pivot point, seamlessly transitioning from soft to hard knee for more natural results. Yet unlike most limiters that are designed to be transparent, the Komit Clipper is designed to introduce personality to your recordings. The Clipper simulates the sound created by old-school diode bridge circuits from the early days of radio. These clip the input signal when they exceed the headroom. Same deal only here, you are in complete control. Ten settings are graduated from mild harmonic overload to extreme nasty. Think of Nine Inch Nails.To ensure absolute signal integrity, full size discrete electronics are employed throughout while the vintage style Hammond broadcast transformers add extra warmth to the signal path. A variable level control provides gain make-up or can be used to drive the Clipper for added distortion. Dual ballistic VU metering makes it easy to simultaneously view compression and output when making adjustments. Designed for use with all 500 series racks, the Komit can be linked for full stereo operation. When used with the Radial Workhorse, the Omniport is assigned as a key input for frequency dependent compression, de-essing, ducking or any number of dynamic manipulation effects.Applications:Channel StripThe Komit is the ideal compressor to compliment a 'gold' channel strip. Feed the mic into a PowerPre, an EQ and the Komit can keep dynamics under control for more professional results. Stereo programThe Komit can be set to stereo mode by linking two Komits together. This is great for mastering. And even though the two units will share the same time constant, independent compression retains the full stereo image. DuckingUse the key input (via the Omniport on the Workhorse) to automatically duck a guitar track (lower the level) when the vocalist begins to sing. Simply connect the TRS output from the PowerPre into the Omniport key input.Single dial

DBX 160SL Blue Series Audio Compressor Limiter $3399.95 With the DBX 160SL Blue Series Audio Compressor Limiter , DBX introduces the AutoVelocity technology. With AutoVelocity it is now easier than ever to dial up the exact attack and release effect you are looking for, via the program-dependent, or non program dependent manual mode. Still on board the DBX 160SL compressor is the venerable dbx Auto mode. Now with this amazing DBX compressor limiter you can set your maximum preferred settings in manual mode, and let the 160SL do the rest for you, depending on your program material. Since its inception the 160S has become the mark for which other compressors reach. As the leader in VCA and compressor design and engineering, DBX is always seeking to improve their products and give you the best possible compression solutions. DBX 160SL Blue Series Audio Compressor Limiter Features Patent-pending AutoVelocity circuit 127dB of Dynamic Range High-Drive output transformer circuit drives 1000 ft. of Belden cable at +30dBu with only .007 percent THD Switchable between Hard-knee and OverEasy Compression Program-dependent ‘Auto,’ AutoVelocity or fully variable attack ad release manual modes Rare earth magnet relays with gold contacts in a hermetically sealed nitrogen environment High-reliability board-to-board connectors with gold-palladium-nickel contacts The DBX 160SL Blue Series compressor features the same striking blue front panel machined from 1/4 inch aircraft aluminum, handcrafted solid aluminum knobs, LEDs mounted individually in machined stainless steel housings, custom VU meters with peak indicators, and heavy gauge chassis. The 160SL combines the best features of all the great DBX compressors, past and present, and gives you more versatile performance than ever before. In addition to having the auto attack and release as well as the hard knee threshold characteristics of the classic DBX 160, the 160SL now offers AutoVelocity manual mode, in addition to DBX’s classic OverEasy mode, made standard by the classic DBX 165A. And speaking of the 165A, all of its features, including variable attack and release controls, as well as DBX's latest limiting algorithm PeakStopPlus, are included in the 160SL compressor limiter! The heart of any dynamics processor is its VCA, and the DBX 160SL is no different. It features dual proprietary V8 VCA modules. This state-of-the-art implementation of DBX’s original Blackmer decilinear VCA boasts an unheard-of 127dB dynamic range and ultra-low distortion. Encased in a specially designed aluminum-zinc housing for shielding and thermal characteristics, the V8 maintains its superior performance in harsh environments. The 160SL takes full advantage of the most technologically superior components available today. Premium active electronics, precision 0.1 percent and 1 percent metal film resistors, great sounding temperature stable polypropylene capacitors, high-reliability board-to-board connectors with gold-palladium-nickel contacts, Jensen transformers,

Black Lion Audio AGB Compressor Limiter $1199 Black Lion Audio introduces another member of the BLA product line; the Black Lion Audio AGB Compressor Limiter . An homage to the venerable Neve 33609, the AGB is a two-channel diode compressor and limiter housed in a 2U rack mount chassis. Imagine a quick, responsive, low noise compressor with powerful control features. The AGB Compressor does everything from smooth and easy compression to weird rhythmic clicks to funky envelope tricks. It's insanely fast and doesn't choke when you really push it. Strap it across your drum bus and smash away. Give your snare a nice, dense crack. Use it for program material. The slower attack mode is great for vocals. Whatever you use it on, you'll find it does the job well, and without raising the noise floor. So where does their design differ from the original? For one, the signal path is a fully balanced, opamp-based circuit. Rotary potentiometers are used instead of stepped potentiometers, giving you more control over things like input level and attack time. Like the original, the Black Lion AGB uses input, interstage, and output transformers.

WAC Lighting THL-HLE-1A-DB Dark Bronze 1 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-1A 1 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-1A-WT White 1 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-1A 1 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-2A-BK Black 2.5 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-2A 2.5 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-2A-BN Brushed Nickel 2.5 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-2A 2.5 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-1A-BK Black 1 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-1A 1 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-2A-DB Dark Bronze 2.5 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-2A 2.5 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-2A-WT White 2.5 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-2A 2.5 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-10A-BN Brushed Nickel 10 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-10A 10 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-10A-BK Black 10 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-10A 10 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

WAC Lighting THL-HLE-10A-DB Dark Bronze 10 Amp Single Live End Track Current Limiter for H Series Track Systems $197.95 WAC Lighting THL-HLE-10A 10 Amp Single Live End Track Current Limiter for H Series Track SystemsThe W.A.C Track Current Limiter is easy to install and assures compliance to California Title 24 or ASHRAE 90.1 requirements. Energy code track installations are subject to wattage limitations based upon the size and usage of the space. Features:The Track Current Limiter may be mounted as a standard canopy, used in place of an "I" connector or as a Live-end. If the track is overloaded, the Current Limiter circuit breaker will trip and shut down power to the trackThe device maybe reset when the overall sum of fixture wattages are reduced below the circuit breaker rating

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Homemade DVD Writer burning laser

Control and monitoring of multiple devices via computer interface

 Control and monitoring of multiple devices  via computer interface

                                                           1James Agajo, 2 A Sylvester Ezewele  

             Department of Electrical/Electronics, Federal Polytechnic, Auchi

Edo State ,Nigeria, Email:  agajojul@yahoo.com, Phone: +2348053312732

Abstract: Control and monitoring of multiple devices  via computer interface  suggest way of  controlling  device via the internet, various interfaces were discussed,  procedure for testing was also analysed, software used were also shown

Keyword: Control, switch, microcontrollers, computer

 Introduction

There has been continuous quest for man to improve his well being through, reactions to problems and challenges posed by his environment. Over the years, computer and computer communication had gained so much attention and grown tremendously, reducing big and expensive mainframes into small and affordable devices. Statistics have shown that most people spend most of their time on computers, since most of their activities locally or globally over a network. Since much time is spent on computer system, it becomes necessary to design a device for controlling switches from computer. Switches are so essential that one can not avoid to use them on a daily basis for putting on or turning off electrical devices, and as a result of these, many devices have been designed by man to help him conquer these problems and challenges posed by physical contact with electricity. The switch control system can range from simply controlling of light without leaving a seat, to being able to switch on industrial electrical devices through a computer. There has to be an interface between industrial electrical devices and a controller, the PC in this case. Interface are required so that the PC can communicate with other devices (Osinuga and oresotu 2001), the interface used in this work is the computer port interface. The microprocessor switch control system is made up of several devices connected together; keypads that transmit commands to the device, fixtures controller that is programmed to on the appliances automatically via a computer system. [1]

 

   MICROPROCESSOR- BASED SWITCH CONTROL SYSTEM:

Yong- Jing Nu (1998), observed that microprocessor based toggle switch control system is primary configured with a power factor corrector (PFC), a square- ware voltage generator, a manually controlled toggle switch and two relay. Toggle switch can select a different number of lamps in operation, resulting in a manual dimming feature.[2]

 

 METHODOLOGY

Software Engineering has internationally accepted software Engineering standards for transforming ideals into an inference engine. They include:

v     The structured system Analysis and Design methodology (SSADM)

v     Prototyping

v     Experts system methodology

v     Usability Engineering methodologies, etc.

 

The methodology applied in the system is prototyping and is discussed below.

 

3.0 duction                                                PROTOTYPING

In electronics, prototyping means building an actual circuit to a design to verity that it works, and to provide a physical plat forms for debugging it, it does not work. Prototyping sometimes converts intangible specifications into a tangible but limited working model of the desired information system. [3]

 

CLASSIFICATION OF SYSTEM PROTOTYPES

System prototypes could be classified into:

1. Evolutionary prototype:  This design is adapted for permanent use after the ideas are clarified and must be built using the program tools that will be used for the final system.

 

1. The throwaway prototype: This design is to be discarded after utilization, basically it is to test ideas and is especially useful for comparing alternative designs for part of a system.[3]

 

STEP INVOLVED IN PROTOTYPING

1. Identify the user’s known information requirements and features needed in the system.
2. Develop a working prototype.
3. Use the prototype, noting need enhancements and changes; this expands the list of known system requirements.
4. Revise the prototype based on information gained through user experience.
5. Repeat these steps as needed to achieve a satisfactory system.

 

  ADVANTAGES OF PROTOPING

1. Requires user involvement.
2. It helps to refine the potential risks associated with the delivery of the system being developed.
3. Prototyping facilitates system implementation since users know what to expect and exposed developers to potential future system enhancements.
4. User can point to features they like or dislike and so indicate shortcomings in an existing and working system more easily, and then they can describe them in a theoretical or proposed system.[4]

DISADVANTAGES OF PROTOTYPING.

              I.      The process of developing a prototype can cause systems to be left unfinished or implemented before they are ready.

            II.      Prototyping can sometimes leads to incomplete documentation and insufficient analysis.

          III.      The process of developing a prototype may require greater involvement and commitment by key users who are already busy with their regular work.

         IV.      If sophisticated software prototypes are employed, the time saving benefit of prototyping can be lost.

           V.      In prototyping, structure of system can be damaged since many changes could be made and it is not suitable for large applications.

 

Our prototype in this project is constructed using a microprocessor to control electrical appliances.[5]

 

  ANALYSIS OF THE EXISTING SYSTEM

The present procedure involves a manual control of the power switch by the industrial electrician. The power control switch is operated with hand by pushing the switch lever to on position if it’s intended to be turned on or off position if it’s intended to be turned off. Basically, during the analysis of this procedure, it is discovered that the operators is at high risk of been electrocuted. Manually, switches have been existing for many years in every home, industry, company, schools and colleges. [6]

These switches are in different standards such as:

1. ON- OFF e.g. toggle switches – it is used to switch the power supply of a circuit. When used with mains electricity, this type of switch must be in the lives wires.
2. (ON – OFF) push- to- make switch is for doorbell.
3. (ON – OFF) push- to- break switch is also for doorbell.

This switch can be “ON” in both positions, switching on a separate device. In each case, it is often called a change over switch example; a SPOT switch can be used to switch ON red lamp in one position and a green lamp in another position.

 

REED SWITCH:

The contacts of a reed switch are closed by bringing a small magnet near the switch. They are used in security circuits, for example to check the doors and closed. Standard reed switches are SPST (simple ON/ OFF)

 

THREE FEATURES OF EXISTING SWITCH

         Contacts (example single pole, double throw)

         Rating (maximum voltage and current)

         Methods of operation (toggle, slide, key etc.

 

                        THE PROBEM OF THE EXISTING SWITCHES (SYSTEM)

v                 Electrocution: Those switches claim a lot of lives as a result of direct contact of the operator with them for example; the operator might be electrocuted in the process of carrying out power change over.

 

v                 Time wastage: it takes time to go from one switch to the other to ON or OFF them whenever there is power failure.

 

v                 Friction: friction is applied in operating these switches. Worn out switches can lead to the damage of the electrical devices which it is controlling.

 

v                 Frequent touching of the switch causes the damage of the switch circuit.

 

v                 Bad switch control might result to serious inferno to industrial equipment and other valuables.

 

 

SWITCHING CIRCUIT

This circuit is made up of BC 337 transistor switching circuit; each circuit is connected to a relay, a transistor and diode. The relay when activated, ON or OFF any appliance connected to it. The three lives from the microprocessor are each connected respectively to the BASE pin of the three corresponding transistor.[6]

 

The circuit is the heart of this module. It comprises of 9-pin Dip-male connector, Max-232, 8051 microprocessor, crystal oscillator.

 

 The circuit connects directly to the computer serial port through a pin cable. The MAX- 232 amplifies signal (VS) that goes into the microprocessor from the computer system through the serial cables. Serial data is transmitted from the PC as a series of positive and negative voltage on a single wire, which serial data occurred at a pre-determined time established by the base wire.

 

The 11-0597MHZ crystal oscillator determines the speed of the 8051 microprocessor used. The microprocessor is connected to the three BC B37A transistor that derives the three relays. Pin 2 an d3 of the serial port are connected to line 14 and 13 of the MAX- 232. [7,8]

 

 

 HARDWARE REQUIREMENTS

 

v     Microprocessor

v     Relays

v     AC bulb

v     Capacitors

v     LEDS

v     Switches

v     Transistor

v     Resistor

v     Diode

 

INSTALLATION PROCESS

The set up program prepares your computer to stall the software from the CD.

 

To install the program;

v     Insert the CD, in the CD program;

v     Double click on CD my computer

v     Double click on CD drive icon

v     Double click on setup icon

v     Follow the screen instructions to complete installation.

 

                

 How to open the software

ü      Click to view start menu

ü      Click on all program

ü      Click on control

ü      Finally click on control

 The interface will appear:

v     Check the ON/ OFF box and click on desired relay button

 

v     When the status is B or D or F the relays are ON, but when the status is A or C or E then the relays are OFF.

 

USER’S GUIDE (MANUAL)

 The user’s manual for the system will accompany the software CD. The aim of this manual is to guide the users on the appropriate steps to follow[9,10]

 

 HARDWARE GUIDE

The switch controller must be connected to the system unit. The guide on how to connect it to the computer are:

 

v     Insert the serial cable female port into “D- shape male 9- pins serial port at the back of system unit and screw.

v     Connect the power cable into any power source of 240V

v     Make sure the computer system cables are properly fixed.

 

TESTING:

Software or hardware testing is very important element of assurance and it represents the ultimate view of specification, design and coding. The main thing here is to execute a program with the intent to search for an error. If the program executes without any notable instate; there the objectives of conceiving it is achieved.

 However, the free flow of the software was realized by removing bugs at early stages of the software development and the hardware was also realized by proper soldering of the components used on the breadboard

 

The New software and hardware project shall be tested thoroughly ensure that it meets the requirements in the specification. Macro et al stated that there are five stages of system testing or levels. These include;

v     Function Testing: The functions and modules that make up the module are tested to ensure their correct operation.

v     Module Testing: The functions are combined to form a module. This module is tested to ensure that its performance meets specifications. In this design the modules, which are tested and it responds positively which shows the modules are independently efficient and reliable.

v     Integration Testing: This is some time called subsystem testing, a set of modules are integrated. As software module and hardware module interact, the testing focus is on modules interface because it is assumed that the modules themselves are correct. This test is carried out to ascertain that those modules do not loose their efficiency and reliability by integrating them into subsystems and systems.

v     Total program testing: sometimes called system testing is the level where all the testing process concentrated more on detecting errors and determining how well user’s requirement are meet.

 

 

PROGRAM DOCUMENTATION (OPERATION)

  Microprocessor- based main switch control system, is a system consisting of software and hardware module. The hardware module is the controller circuit, which must be connected to the system unit and the software module is in a CD-ROM and needed to be installed in the system unit (hard disk). This will only take effect when the controller is properly connected to the computer system through the serial port and to the power source. Any electrical device connected to it can be switch on or off through the interface provide by the software.

Depending on the previous by the software bulbs, when the command button of any relay is clicked, signals goes from there to desirable bulb.

 

When relay 1 is off the status will display “A” but when it is ON, the status will display “B” .

Also when relay 2 is off the status will display “C”, when it is ON the status will display “D”.

Finally when relay 3 is off the status will display “E” but the relay is ON the status will display “F”.

 

IMPLEMENTATION DETAILS

This detail involves the conversion of files, parallel or pilot implementation plans. This involves the change- over procedures. Once the system has been fully designed, tested for a good percentage of perfection and accepted, the change over plan can be made. So this plan is done using the two types below:

 

ü      Parallel change over

ü      Pilot change over.

 

PARALLEL CHANGE OVER:

This system will allow the new system to continue along side with the old system, for weeks or months. The disadvantage of parallel running is the extra effort required to keep both system running.

 

PILOT CHANGE OVER:

Here, the new system is introduced into one of the department or branches of an organization and run until it is proven to be satisfactory. Then if it works with little or no shortcomings, it can then the installed in all the organizations and department or implemented fully everywhere as the case may be.

 

For this project both change over plans will do, but we are implementing the pilot change over plan because this new system has so many advantages over the old system.

 

CONCLUSION

This work is recommended to be used in industries, large firms manufacturing industries e.t.c. This is to provides easy and safe use of the electrical devices; Instructions are programmed into the microprocessor to carry out their functions. The management of any organization using this project should employ computer analyst who will be operating this system.

   The primary objectives of this project is to control electrical devices with computer through serial port was achieved successfully. The microprocessor in the control unit was programmed using assembly language.

 

REFERENCE

[1] Addison, Wesley k. and Takashi 9 (1990) Power electronics for the 

microprocessor Age, Oxford University Press.

1. [2] Alluwalia. A and yeralan: Programming and interfacing the         
2. [3]  Anigbogu  S.O ( 1997) Basic computer electronic and logic circuits Christon      

International Company LTD, Awka.

[4] Beyond Logic (2008), Interfacing the serial RS-232 Port, (http//www.Interface com/ MAX-232/html)

[5] Boylston, R.L.,and L Nashalsky. Electronic Devices and

[6] Chris Kotoroski, (2008) A push –to – break breaks  word toggle switch.

Circuit theory. Prentice – Hal/ of India private Ltd., New Delhi, 8th edition, 2004.

[7] Douglas, V.H; Microprocessor and Interfacing” .Tata McGraw-Hill, New Delhi; 2nd Edition, 1999.

 

[8] Hennessy, J,L and Patterson D.A (2002),  Interfacing the serial RS-232 Port

(http//www.interface.com/Max-232/html).

 

[9] Hughes Edward; Electrical Technology, ELBS and Longman group; 4th  

Edition, 1972 8951 micro controller adhesion_ wesley,1995.

[10] Ismail, and V.M Rooney, (1987) Microprocessor Hardware and Software Concepts IT Press, Chicago.

 

 

 

 

About the Author

James Agajo is into a P.H.D programme in digital signal processing related area, he has a Master Degree in Electronics and telecommunication Engineering and also possesses a Bachelor degree in Electronics and Computer Engineering from the Federal University of Technology Minna Nigeria. To he's record he has carried out researches in various areas as it concern telecommunication with particular emphasis on wirless communication network. His interest is in intelligent system development with a high flare for Engineering and Scientific research.He has Designed and implemented the most resent computer controlled robotic arm with a working grip mechanism 2006 which was aired on a national television , he has carried out work on using blue tooth technology to communicate with microcontroller. Has also worked on thumb print technology to develop high tech security systems with many more He is presently on secondment with UNESCO TVE as a supervisor and a resource person. James is presently registered with the Nigeria Society of Engineers.