A Summer Internship Project Report on

WORKING STUDY OF PHILIPS LED AND OTHER TESTING

PRODUCTS

Submitted in partial fulfillment of the requirement for the degree of

B.Tech(ECE)3rd year

University of Technology and Management,Shillong

By

Chakresh Tiwari

Roll No.R020113004

Under the guidance of

Mr. Himanshu Semwal

A study conducted at

PHILIPS LIGHTING LIMITED, NOIDA

University of technology and Management

Shillong (mentored by UPES Dehradun)

2013-2017

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Acknowledgement

It is indeed of great moment of pleasure to express my senses of per found gratitude to all

the people who have been instrumental in making my training a rich experience. For this, I

would like to thank Mr. Himanshu Semwal who talked to the concerned person and without

whom an internship with the company would not have been possible. I express my gratitude to

Mr. Amit Jain (Director), for giving me an opportunity to work and make the best out of my

internship.

I thank my college University of Technology and Management Shillong, for having

given me this opportunity to put to practice, the theoretical knowledge that I imparted from the

program.

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Introduction

Here,I got opportunity to have hands on experience on the real Devices. Testing of products,

Enhancement in the manufacturing, Neat Soldering and desoldering hands on practice.

Specially, to work and help the Employees in their work and their projects. Got to learn how AC to AC

converter AC to DC converter works. Dimming Effect , Flyback converter which is used in making

Dimming Products.

Tests Performed

1. Strife test

2. Surge test

3. Thermal test

4. Reliability test

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1. Surge Test

Why Do Motors Fail?

Motors fail both mechanically and electrically. Electrical failure occurs due to shorting which is caused

by a breakdown of winding insulation. There are three types of insulation failure that can occur:

• Ground wall insulation (the primary insulation between the copper winding and steel core)

• Phase to phase insulation (the secondary insulation between the end turns of a random wound motor)

• Turn to turn insulation (the secondary insulation-applied to the surface of the copper

winding)Stresses that cause electrical motor failure include differential thermal stress, different

coefficients of expansion, varnish weakening at high temperatures, magnetic force due to winding

currents, environmental contaminants, and moisture. These stresses cause looseness, motion, and wear

of the insulation.

Why Perform Surge Testing?

Insulation deterioration is one of the first signs that a motor is going to fail electrically. Since secondary

insulation is least able to sustain wear, shorting usually occurs here before the thicker, ground wall

insulation is affected. Surge testing is a non-destructive test and detects the early stages of secondary

insulation deterioration. The cost of motor failure is measured by interruption of plant output as well as

extent of repair or replacement. Surge testing greatly decreases both. It detects failure early enough so

that repair or replacement can be scheduled during a normal shutdown rather than an emergency

outage. In addition, damage to the motor is minimized.

How is Surge Testing Performed?

The test can be performed on the motor winding without actually connecting to the motor itself. The

test equipment can be connected to the load side of the motor starter. During the test a voltage pulse is

placed across two of the three windings while the third is grounded. The magnitude of the pulse is

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approximately twice the operating voltage plus 1000 volts. Therefore, low voltage starters operating at

460 volts, are tested at approximately 2000 volts and medium voltage starters, operating at 2400 volts,

are tested at approximately 6000 volts. Pulses are produced at a frequency of 60 times per second and

dissipate in approximately 100 microseconds. The output, which is a dampened sign wave, is then

monitored on an oscilloscope. Since all three windings should have the same surge patterns, the two

patterns being monitored should appear as a single overlapping wave. This procedure is repeated for all

three pairs of windings. Series In some cases if the two waves separate as the test voltage is increased,

this indicates weakened insulation which in time will lead to electrical failure.

2. Strife Test

A highly accelerated life test (HALT), is a stress testing methodology for determining product reliability.

HALT testing is currently in use by most major manufacturing organizations to improve product

reliability in a variety of industries, including electronics, computer, medical and military.HALT can be

effectively used multiple times over a product's life time. During product development, it can find design

weakness when changes are much less costly to make. By finding weaknesses and making changes early,

HALT can lower product development costs and compress time to market. When HALT is used at the

time a product is being introduced into the market, it can expose problems caused by new

manufacturing processes. When used after a product has been introduced into the market, HALT can be

used to audit product reliability caused by changes in components, manufacturing processes or suppliers

etc.

Highly accelerated life testing (HALT) techniques are important in uncovering many of the weak links of

a new product. These discovery tests rapidly find weaknesses using accelerated stress conditions. The

goal of HALT is to proactively find weaknesses and fix them thereby increasing product reliability.

Because of its accelerated nature, HALT is typically faster and less expensive than traditional testing

techniques.

Environmental stresses are applied in a HALT procedure,[1] eventually reaching a level significantly

beyond that expected during use. The stresses used in HALT are typically hot and cold temperatures,

temperature cycles, random vibration, power margining and power cycling. The product under test is in

operation during HALT and is continuously monitored for failures. As stress-induced failures occur, the

cause should be determined, and if possible, the problem should be repaired so that the test can

continue to find other weaknesses.

A specialized environmental chamber is required for HALT. A suitable chamber also has to be capable of

applying pseudo-random vibration with a suitable profile in relation to frequency. The HALT chamber

should apply random vibration energy to 10,000 Hz in 6 DOF (degrees of freedom). Sometimes HALT

chambers are called repetitive shock chambers because pneumatic air hammers are used to produce

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vibration. The chamber should also be capable of rapid changes in temperature, 50 degrees C/minute

should be considered a minimum rate of change. Usually high power resistive heating elements are used

for heating and Liquid Nitrogen (LN2) is used for cooling. HALT is conducted before qualification testing.

By catching failures early, flaws are found earlier in the acceptance process, eliminating repetitive later-

stage reviews.

3. Thermal Test

Infrared and thermal testing is one of many Nondestructive testing techniques designated by the

American Society for Nondestructive Testing (ASNT).[1] Infrared Thermography is the science of

measuring and mapping surface temperatures.

"Infrared thermography, a nondestructive, remote sensing technique, has proved to be an effective,

convenient, and economical method of testing concrete. It can detect internal voids, delaminations, and

cracks in concrete structures such as bridge decks, highway pavements, garage floors, parking lot

pavements, and building walls. As a testing technique, some of its most important qualities are that (1) it

is accurate; (2) it is repeatable; (3) it need not inconvenience the public; and (4) it is economical." [2]

An infrared thermographic scanning system can measure and view temperature patterns based upon

temperature differences as small as a few hundredths of a degree Celsius. Infrared thermographic

testing may be performed during day or night, depending on environmental conditions and the desired

results.

All objects emit electromagnetic radiation of a wavelength dependent on the object’s temperature. The

frequency of the radiation is inversely proportional to the temperature. In infrared thermography, the

radiation is detected and measured with infrared imagers (radiometers). The imagers contain an

infrared detector that converts the emitting radiation into electrical signals that are displayed on a color

or black & white computer display monitor.

A typical application for regularly available IR Thermographic equipment is looking for “hot spots” in

electrical equipment, which illustrates high resistance areas in electrical circuits. These “hot spots” are

usually measured in the range of 40 °C to 150 °C (70 to 270 °F) above ambient temperatures. But, when

engineers use its patented proprietary systems to locate subsurface targets such as Underground

Storage Tanks (USTs), pipelines, pipeline leaks and their plumes, and in this project, hidden tunnels, we

are looking for temperature patterns typically in the range of 0.01 °C to 1 °C above or below ambient

temperatures.

After the thermal data is processed, it can be displayed on a monitor in multiple shades of gray scale or

color. The colors displayed on the thermogram are arbitrarily set by the Thermographer to best illustrate

the infrared data being analyzed.

In this roofing investigation application, infrared thermographic data was collected during daytime

hours, on both sunny and rainy days. This data collection time allowed for solar heating of the roof, and

any entrapped water within the roofing system, during the daylight hours. IR data was observed until

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the roof had sufficiently warmed to allow detection of the entrapped wet areas because of their ability

to collect and store more heat than the dry insulated areas. The wet areas would also transfer the heat

at a faster rate than the dry insulated roof areas. At this point in time, the wet areas showed up as

warmer roof surface temperatures than the surrounding dry background areas of the roof. During the

rainy day, with minimum solar loading, any entrapped leak plumes would become evident because of

their cooler temperature as compared to the dry roof areas

An infrared thermographic scanning system measures surface temperatures only. But the surface

temperatures that are measured on the surface of the ground, above a buried pipeline, are, to a great

extent, dependent upon the subsurface conditions.

The subsurface configuration effects are based upon the theory that energy cannot be stopped from

flowing from warmer to cooler areas, it can only be slowed down by the insulating effects of the

material through which it is flowing. Various types of construction materials have different insulating

abilities. In addition, differing types of pipeline defects have different insulating values.

4. Reliability Test

Software reliability testing is a field of software testing that relates to testing a software's ability to

function, given environmental conditions, for a particular amount of time. Software reliability testing

helps discover many problems in the software design and functionality.

Software reliability is the probability that software will work properly in a specified environment and for

a given amount of time. Using the following formula, the probability of failure is calculated by testing a

sample of all available input states. Mean Time Between Failure(MTBT)=Mean Time TO Failure(MTTT)+

Mean Time To Repair(MTTR)

Probability = Number of failing cases / Total number of cases under consideration

The set of all possible input states is called the input space. To find reliability of software, we need to

find output space from given input space and software.For reliability testing, data is gathered from

various stages of development, such as the design and operating stages. The tests are limited due to

restrictions such as cost and time restrictions. Statistical samples are obtained from the software

products to test for the reliability of the software. Once sufficient data or information is gathered,

statistical studies are done. Time constraints are handled by applying fixed dates or deadlines for the

tests to be performed. After this phase, design of the software is stopped and the actual

implementation phase starts. As there are restrictions on costs and time, the data is gathered carefully

so that each data has some purpose and gets its expected precision.To achieve the satisfactory results

from reliability testing one must take care of some reliability characteristics. For example, Mean Time to

Failure (MTTF)[3] is measured in terms of three factors: operating time, number of on off cycles, and

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calendar time.If the restrictions are on operation time or if the focus is on first point for improvement,

then one can apply compressed time accelerations to reduce the testing time. If the focus is on calendar

time (i.e. if there are predefined deadlines), then intensified stress testing is used.

Software reliability is measured in terms of mean time between failures (MTBF).

MTBF consists of mean time to failure (MTTF) and mean time to repair (MTTR). MTTF is the

difference of time between two consecutive failures and MTTR is the time required to fix the

failure. Reliability for good software is a number between 0 and 1. Reliability increases when

errors or bugs from the program are removed.

For example, if MTBF = 1000 hours for average software, then the software should work for

1000 h.

Flyback Converter

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The flyback converter is used in both AC/DC and DC/DC conversion with galvanic isolation

between the input and any outputs. The flyback converter is a buck-boost converter with

the inductor split to form a transformer, so that the voltage ratios are multiplied with an

additional advantage of isolation. When driving for example a plasma lamp or a voltage

multiplier the rectifying diode of the boost converter is left out and the device is called a

flyback transformer.The schematic of a flyback converter can be seen in Fig. 1. It is equivalent

to that of a buck-boost converter,[1] with the inductor split to form a transformer. Therefore

the operating principle of both converters is very close:When the switch is closed (top of Fig. 2),

the primary of the transformer is directly connected to the input voltage source. The primary

current and magnetic flux in the transformer increases, storing energy in the transformer. The

voltage induced in the secondary winding is negative, so the diode is reverse-biased (i.e.,

blocked). The output capacitor supplies energy to the output load.When the switch is opened

(bottom of Fig. 2), the primary current and magnetic flux drops. The secondary voltage is

positive, forward-biasing the diode, allowing current to flow from the transformer. The energy

from the transformer core recharges the capacitor and supplies the load.The operation of

storing energy in the transformer before transferring to the output of the converter allows the

topology to easily generate multiple outputs with little additional circuitry, although the output

voltages have to be able to match each other through the turns ratio. Also there is a need for a

controlling rail which has to be loaded before load is applied to the uncontrolled rails, this is to

allow the PWM to open up and supply enough energy to the transformer.

Operations

The flyback converter is an isolated power converter. The two prevailing control schemes

are voltage mode control and current mode control (in the majority of cases current mode

control needs to be dominant for stability during operation). Both require a signal related

to the output voltage. There are three common ways to generate this voltage. The first is to

use an optocoupler on the secondary circuitry to send a signal to the controller. The second

is to wind a separate winding on the coil and rely on the cross regulation of the design. The

third consists on sampling the voltage amplitude on the primary side, during the discharge,

referenced to the standing primary DC voltage.

The first technique involving an optocoupler has been used to obtain tight voltage and

current regulation, whereas the second approach has been developed for cost-sensitive

applications where the output does not need to be as tightly controlled, but up to 11

components including the optocoupler could be eliminated from the overall design. Also, in

applications where reliability is critical, optocouplers can be detrimental to the MTBF

(Mean Time Between Failure) calculations. The third technique, primary-side sensing, can

be as accurate as the first and more economical than the second, yet requires a minimum

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load so that the discharge-event keeps occurring, providing the opportunities to sample the

1:N secondary voltage at the primary winding (during Tdischarge, as per Fig3).

A variation in primary-side sensing technology is where the output voltage and current are

regulated by monitoring the waveforms in the auxiliary winding used to power the control

IC itself, which have improved the accuracy of both voltage and current regulation. The

auxiliary primary winding is used in the same discharge phase as the remaining

secondaries, but it builds a rectified voltage referenced commonly with the primary DC,

hence considered on the primary side.

Previously, a measurement was taken across the whole of the flyback waveform which led

to error, but it was realized that measurements at the so-called knee point (when the

secondary current is zero, see Fig. 3) allow for a much more accurate measurement of what

is happening on the secondary side. This topology is now replacing ringing choke

converters (RCCs) in applications such as mobile phone chargers.

Limitations

Continuous mode has the following disadvantages, which complicate the control of the

converter:The voltage feedback loop requires a lower bandwidth due to a right half plane

zero in the response of the converter. The current feedback loop used in current mode

control needs slope compensation in cases where the duty cycle is above 50%. The power

switches are now turning on with positive current flow - this means that in addition to

turn-off speed, the switch turn-on speed is also important for efficiency and reducing waste

heat in the switching element.Discontinuous mode has the following disadvantages, which

limit the efficiency of the converter:

High RMS and peak currents in the design

High flux excursions in the inductor

Applications

Low-power switch-mode power supplies (cell phone charger, standby power supply in

PCs)

Low-cost multiple-output power supplies (e.g., main PC supplies <250 W[citation

needed])

High voltage supply for the CRT in TVs and monitors (the flyback converter is often

combined with the horizontal deflection drive)

High voltage generation (e.g., for xenon flash lamps, lasers, copiers, etc.) Isolated gate

driver

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Major Office Locations in India

Gurgaon

(Corporate Office and Northern Regional Office)

Visit/Write

Philips India Limited

9th Floor, DLF 9-B,

DLF Cyber City,

Sector 25, DLF Phase – 3,

Gurgaon – 122002, India.

Tel: +91-

Noida

(Lightig and healthcare)

Philips India Limited

C-46,47,Sector 57

Noida-201301

Kolkata

(Registered Office and Eastern Regional Office)

Visit/Write

Philips India Limited

7, Justice Chandra Madhab Road,

Kolkata – 700020, India.

Tel: +91-33-24867621

Bengaluru

Visit/Write

Philips India Limited

Philips Innovation Campus

MFAR Manyata Tech Park,

Nagavara,

Bangalore – 560045, India.

Tel: +91-80-41890000

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Chennai

(Southern Regional Office)

Visit/Write

Philips India Limited

Temple Towers, 5th Floor,

Old No: 476, New No: 672,

Anna Salai, Nandanam,

Chennai – 600035, India.

Tel: +91-44-66501000

Hyderabad

Philips India Limited

6-3-1109/103, 3rd Floor,

Jewel Pawani Towers,

Raj Bhavan Road, Somajiguda,

Hyderabad – 500082, India.

Tel: +91-40-66467676

Mumbai

(Western Regional Office)

Visit/Write

Philips India Limited

Technopolis Knowledge Park,

Mahakali Caves Road,

Chakala, Andheri (E),

Mumbai – 400093, India.

Tel: +91-22-66912000

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HISTORY

The Philips Company was founded in 1891 by Gerard Philips and his father Frederik.

Frederik, a banker based in Zaltbommel, financed the purchase and setup of a modest, empty

\factory building in Eindhoven, where the company started the production of carbon-filament

lamps and other electro-technical products in 1892. This first factory has been adapted and is

used as a museum.

PHILIPS LOGO

PHILIPS CURRENT LOGO

Company Profile

Royal Philips- is a diversified health and well-being company, focused on improving people’s

lives through meaningful innovation in the areas of Healthcare, Consumer Lifestyle and

Lighting. Headquartered in the Netherlands, Philips posted 2013 sales of EUR 23.3 billion and

employs approximately 115,000 employees with sales and services in more than 100 countries.

The company is a leader in cardiac care, acute care and home healthcare, energy efficient

lighting solutions and new lighting applications, as well as male shaving and grooming and oral

healthcare.

Vision and Mission

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Vision

At Philips, we strive to make the world healthier and more sustainable through

innovation. Our goal is to improve the lives of 3 billion people a year by 2025. We will be the

best place to work for people who share our passion. Together we will deliver superior value for

our customers and shareholders.

Mission

Improving people’s lives through meaningful innovation.

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Refrences

1) www.philips.com

2) www.electrolux.com

3) www.wikipedia.com

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