WELCOME

A PRESENTATION ON PRACTICAL TRAINING TAKEN AT INSTRUMENTATION LIMITED ,KOTA

INTRODUCTION “INSTRUMENTATION LTD, KOTA” is a govt. of India Enterprise established in Kota (Raj.) in 1966-67 It has its plant at Kota,& Palakkad (Kerala) with over 25 years of experience and a dedicated work force. The men are well experienced & also give exposure to various new technologies. .

For assembly &testing of hi-tech electronic instrument, totally dust free air conditional hall are used with static protection. Rajasthan electronics & Instruments ltd. (REIL) Jaipur is a subsidiary of IL and is manufacturing & supplying non conventional energy devices and electronic energy meters. The products manufactured at IL are accredited with ISO 9000 series quality system certification. IL has supplied over 3000 units of mini UPS ranging from 1kva to 150 kva. It has supplied instruments on turn key basis for 2 thermal power stations in Malaysia & established a service center at Kufa complex in Iraq.

I have visited following sections during my training period that are:- Railways Signaling Relay department Card Assembly (PCB centre) UPS (Engineering, Production, Servicing) centre

RAILWAY SIGNALING RELAYS (RSR) A relay is an electrical device that opens or closes several circuits in response to a current in another circuit. By energizing / de-energizing one relay, several other relay circuits can be controlled by contacts of that relay. When the relay coil is energized , this creates an electromagnetic field that attracts the relay armature to the coil. Attached to this armature is a mechanism for either opening or closing the relay contacts that are electrically independent from the input voltage to the relay coil. The relay can in turn control (or switch) other circuits. These other circuits that are switched, may or may not be at the same voltage as the relay coil whose contacts are doing the switching.

Most relays have two types of contacts Most relays have two types of contacts. One set of contacts are “made” or closed when the relay is energized. These are known as “Front Contacts.” Conversely these contacts are opened or broken when the relay is de-energized. Back contacts of the relay on the other hand are “made” (closed) when the relay is de-energized and broken (open) when the relay is energized. HOWEVER, I.L manufactures three types of signaling relays. They are: -

LINE RELAY: - This type of relay is used for classification of line LINE RELAY: - This type of relay is used for classification of line. It gives signal to lines for up and down. There are two signals Red and Green. Here, red signal indicates that the line is busy whereas the green signal indicates that line is clear. TRACK RELAY: - This type of relay is used for changing track at railway station. As we know only two lines up and down are present & number of lines are present at railway station. KEYLOCK RELAY: - These are automatic relay & are used for the protection of accidents when train arrives & the gate is automatically closed. These all types of relays are controlled at control room  

Card Assembly (pcb centre) It is a process of mounting the components on PCB Types Of Card Assembly- 1.Through Hole 2. Surface Mount Technology

1. Through Hole Technology: - In this process components are mounted through drilled hole on the PCB. In this wave-soldering machine is used for Soldering Through Hole components The process consisting of 4 sub process 1. Fluxing 2. Pre heating 3. Wave soldering 4. Rework &touch up

Fluxing is done to remove the oxidation and other containments; no clean flux is used as solvents. After fluxing & removal of excess flux, the PCB moves to the pre heating section, where the solder side of the PCB receives hot radiations from heaters & this removes the oxidation & other containments. After pre-heating. We move to wave soldering. Different cards on which the components like transformer, high power resistance, capacitance to be mounted are placed on system and soldered by wave soldering.

WAVE SOLDERING MACHINE Wave soldering is a large-scale soldering process by which electronic components are soldered to a printed circuit board (PCB) to form an electronic assembly. The name is derived from the use of waves of molten solder to attach metal components to the PCB. The process uses a tank to hold a quantity of molten solder; the components are inserted into or placed on the PCB . The process is much faster and can create a higher quality product than manual soldering of components.

2. Surface Mount Technology (SMT) Surface mount technology (SMT) IS AN ELECTRONICS ASSEMBLY TECHNIQUE where Electronic components are mounted to the surface of printed circuit board without holes drilled through the board for insertion of component leads This method is a very efficient and fast technology. It saves the cost of placing the component &time about 30% more faster than the work power.

Procedure for SMT Surface mount assembly is basically a four-step process:- 1.Print the solder paste/ glue. 2.Place the components. 3.Reflow the paste to form the solder interconnection between the component and the land area of the board. 4.Rework

Equipments used in SMT- 1.Screen Printer- To print the solder paste / glue on the board .The places on the pcb where we want to fix the component is made shining by putting this paste.

2.Pick & mount machine- We develop a program showing which component it’s size, width,etc… Here the components are picked up and placed at appropriate location. There are different nozzles as per the component. They create a vacuum ,pick up the component and place them on the PCB. Components are fed through three methods reel , tray & tube It’s speed of placing is 20,000 components per hour.

Pick & mount machine

3.Re-Flow Oven- Here hot air comes and melts the solder which grips the particular component. There is a blower which cools the PCB when it is very hot.

4. Image taking – Here , first of all a master PCB is created with utmost care where all the components are mounted at correct places. Then , it’s image is taken by image taking machine.Then this image is compared with other PCB’s image and faults are found if any. If a fault is found PCB is sent to rework station where that faulty component is removed by a heater which melts the solder. Then by looking at screen we can place that component at right position.

After the PCB’s are made ,they are given an identification number of ten digits as:- XX XX X X XXXX First two digits show manufacturer’s code Next two digits show the year in which PCB was made like 07,08,09 etc…….. Next single digit for month as 1 to 9 till September and then A,B,C for oct. ,nov.,& dec. Next single digit for manufacturer’s unit Then 4 digit serial number Thus total 9999 PCB’s can be identified by this code in particular year & month

UPS (Uninterrupted Power Supply) The basic function of UPS is to continue power supply to critical load within its specified tolerances during a failure or deterioration of the normal power supply The UPS System basically consists of Rectifier, Inverter, Transfer Switch and Battery. The basic UPS consist of rectifier/charger, inverter, external source of stored power (usually a battery), associated circuitry, protective devices and accessories for proper operation.

Basic Types Of UPS STANBY UPS With this type of UPS, a user's equipment is normally connected directly to incoming utility power with the same voltage transient clamping devices used in a common surge protected plug strip connected across the power . When the incoming utility voltage falls below a predetermined level the SPS turns on its internal DC-AC inverter circuitry, which is powered from an internal storage battery. The SPS then mechanically switches the connected equipment on to its DC-AC inverter output. The switchover time can be as long as 25 milliseconds depending on the amount of time it takes the Standby UPS to detect the lost utility voltage.

LINE INTERACTIVE UPS - The Line-Interactive UPS is similar in operation to a Standby UPS, but with the addition of a multi-tap variable-voltage autotransformer. This is a special type of electrical transformer that can add or subtract powered coils of wire, thereby increasing or decreasing the magnetic field and the output voltage of the transformer.

The basic parts of UPS by which it is Assembled Are- Inverter Card –It work as a DC to AC converter. Relay & charger card- It contain Rectifier Which act as AC to DC converter. Control Card –This card control are the assembled part of UPS. Display card - This card is used to display the rating of the UPS such as Voltage ,current or power.

ARCHITECTURE OF UPS -

WORKING OF UPS: Under normal condition, the battery charger supplies the entire power necessary to the inverter for supplying the load, and simultaneously charges the battery in float charging condition. The battery charger affects charging the battery automatically. If power failure occurs, the inverter is supplied the DC power from battery and supplies continuously the stable AC power to the load. After restoration of power the UPS come back to normal operation. The transfer switch or static switch is used to transfer load from inverter mode to bypass mode. In case inverter becomes faulty the load is transferred from inverter to Bypass automatically. The battery used in home segment is generally Lb-Acid tubular (wet type) batteries and require maintenance periodically. The most critical part of maintenance of battery is to keep level of acid to required level by adding distilled water. Also the life of battery is of 2-3 years.

THANK YOU ! MADE BY:- HARSHAL NIGAM B.E 3rd YEAR(ECE)