lecture 1

Short Course on Electronic Project Design and FabricationShort Course on Electronic Project Design and FabricationShort Course on Electronic Project Design and FabricationShort Course on Electronic Project Design and Fabrication

Jointly Organized by: Dept. of EEE and IEEE RUET

Lecture 1: Resistor Capacitor, Induction, Transformer, Diode

Problem 1: Design a DC Power Supply.

Solve: You can make a DC power Supply from the following Circuit.

If it is 7805, then it is +5V Voltage regulator, if it is 7809, then it is +9V voltage regulator. On the other hand if it is 790

then it is -5V voltage regulator, if it is 7909 then it is

Here, S1 – Switch, 3A – 3A Fuse, T1 - Transformer,

microfarad. You can also use different transformer, such as 220V/12V transformer.

Abdullah Al Bashit

Color Coding of Resistor:

Black Brown Red Orange Yellow

0 1 2 3 4

Resistance = (1st

Band|2nd

Band)*103rd Band

± Tolerance

Details of Color coding, Tolerance, Resistor Power

Thermistor, LDR, Varistor etc with example will be

Application of Resistor:

Lightbulb

There is nothing special about a lightbulb filament

metallic gum wrapper and connecting the wrapper across the terminals of a 9

instantly burn out. Edison solved this technical challenge by encasing the filament in an evacuated bulb, which

prevented burning, since burning requires oxygen

Fuse

A fuse is a device inserted in a circuit tollbooth

made of metals having a relatively low melting point. If too much current passes through the fuse, it melts, opening the

circuit. The purpose is to make sure that the building's wires do not carry so much current that they themselves will get

hot enough to start a fire. Most modern houses use circuit breakers instead of fuses, although fuses are still common in

Editor: MD. Mahbub H


Jointly Organized by: Dept. of EEE and IEEE RUET Student Branch

Lecture 1: Resistor Capacitor, Induction, Transformer, Diode, Relay, Project Board, Multimeter

You can make a DC power Supply from the following Circuit. In the figure LM78XX, XX means 05,09,12 etc.

it is 7805, then it is +5V Voltage regulator, if it is 7809, then it is +9V voltage regulator. On the other hand if it is 790

5V voltage regulator, if it is 7909 then it is -9V voltage regulator IC.

sformer, D – Diode, C – Capacitor, LM78XX – Voltage regulator IC.

You can also use different transformer, such as 220V/12V transformer.

Resistor Abdullah Al Bashit, EEE-061048, RUET. email: [email protected]

Yellow Green Blue Violate Gray White Gold

5 6 7 8 9 5%

± Tolerance

olerance, Resistor Power rating, Resistor types, Series Parallel combination of

etc with example will be explained in the class lecture.

There is nothing special about a lightbulb filament - you can easily make a lightbulb by cutting a narrow wa

metallic gum wrapper and connecting the wrapper across the terminals of a 9-volt battery. The trouble is that it will


oxygen.

A fuse is a device inserted in a circuit tollbooth-style in the same manner as an ammeter. It is simply a piece of wire

latively low melting point. If too much current passes through the fuse, it melts, opening the


houses use circuit breakers instead of fuses, although fuses are still common in

D

C

Hasan, EEE-061017 & Tanvir Hussain, EEE-061049, RU

1

, Relay, Project Board, Multimeter

In the figure LM78XX, XX means 05,09,12 etc.

it is 7805, then it is +5V Voltage regulator, if it is 7809, then it is +9V voltage regulator. On the other hand if it is 7905

Voltage regulator IC. uF means

Silver None

10% 20%

el combination of Resistors,

you can easily make a lightbulb by cutting a narrow waist into a

volt battery. The trouble is that it will


style in the same manner as an ammeter. It is simply a piece of wire

latively low melting point. If too much current passes through the fuse, it melts, opening the


houses use circuit breakers instead of fuses, although fuses are still common in

UET



cars and small devices. A circuit breaker is a switch operated by a coiled

enough current flows. The advantage is that once you turn

current, you can immediately flip the switch closed. In the days of fuses, one might get caught without a replacement

fuse, or even be tempted to stuff aluminum

Voltmeter

A voltmeter is nothing more than an ammeter with an additional high

forced to flow.

Polygraph

The polygraph, or "lie detector," is really just a set of meters for recording physical measures of the subject's

psychological stress, such as sweating and quickened heartbeat. The real

principle that dry skin is a good insulator,

nervous simply because of the situation, and a practiced liar may not even break a sweat.

Heater

In Home we use room heater, oven etc. These devices

Details of Capacitor voltage rating, Series parallel connection, types,

etc. will be explained in the class.

Application of Capacitor:

Energy storage

A capacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary

battery. Capacitors are commonly used in elect

(This prevents loss of information in volatile memory.)

Pulsed power and weapons

Groups of large, specially constructed, low-

pulses of current for many pulsed power applications. These include

lasers (especially TEA lasers), pulse forming networks

Large capacitor banks(Reservoir) are used as energy sources for the

detonators in nuclear weapons and other specialty weapons. Experimental work is under way using banks of capacitors as

power sources for electromagnetic armor and electromagnetic

Power conditioning

Reservoir capacitors are used in power supplies

also be used in charge pump circuits as the energy storage element in the generation of higher voltages than the input

voltage (such as stun gun). Capacitors are connected in parallel with the power circuits of most electronic devices and

larger systems (such as factories) to shunt away and conceal current fluctuations from the primary power source to

Abu Sadat Saym



cars and small devices. A circuit breaker is a switch operated by a coiled-wire magnet, which opens the circuit when

enough current flows. The advantage is that once you turn off some of the appliances that were sucking up too much


aluminum foil in as a replacement, defeating the safety feature.

A voltmeter is nothing more than an ammeter with an additional high-value resistor through which the current is also

h, or "lie detector," is really just a set of meters for recording physical measures of the subject's

psychological stress, such as sweating and quickened heartbeat. The real-time sweat measurement works on the

principle that dry skin is a good insulator, but sweaty skin is a conductor. Of course a truthful subject may become

nervous simply because of the situation, and a practiced liar may not even break a sweat.

In Home we use room heater, oven etc. These devices produce heat from a resistor through which high current flows.

Capacitor

Details of Capacitor voltage rating, Series parallel connection, types, energy stored in the capacitor, charging, discharging

pacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary

. Capacitors are commonly used in electronic devices to maintain power supply while batteries are being changed.

(This prevents loss of information in volatile memory.)

-inductance high-voltage capacitors (capacitor banks

applications. These include electromagnetic forming

pulse forming networks, radar, fusion research, and particle accelerators

servoir) are used as energy sources for the exploding-bridge wire detonators

and other specialty weapons. Experimental work is under way using banks of capacitors as

and electromagnetic railguns or coilguns.

power supplies where they smooth the output of a full or half wave

circuits as the energy storage element in the generation of higher voltages than the input

Capacitors are connected in parallel with the power circuits of most electronic devices and

systems (such as factories) to shunt away and conceal current fluctuations from the primary power source to

Capacitance = (1st Code|2

nd Code)*10^3

rd

Capacitance of the above mica capacitor

Abu Sadat Saym, EEE-061001, RUET

2

wire magnet, which opens the circuit when

off some of the appliances that were sucking up too much


as a replacement, defeating the safety feature.

value resistor through which the current is also

h, or "lie detector," is really just a set of meters for recording physical measures of the subject's

time sweat measurement works on the

but sweaty skin is a conductor. Of course a truthful subject may become

h which high current flows.

energy stored in the capacitor, charging, discharging

pacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary

ronic devices to maintain power supply while batteries are being changed.

capacitor banks) are used to supply huge

electromagnetic forming, Marx generators, pulsed

particle accelerators.

wire detonators or slapper

and other specialty weapons. Experimental work is under way using banks of capacitors as

where they smooth the output of a full or half wave rectifier. They can

circuits as the energy storage element in the generation of higher voltages than the input

Capacitors are connected in parallel with the power circuits of most electronic devices and

systems (such as factories) to shunt away and conceal current fluctuations from the primary power source to

rd Code ± Tolerance pF

capacitor is 10*10^4±10% pF


3


provide a "clean" power supply for signal or control circuits. Audio equipment, for example, uses several capacitors in

this way, to shunt away power line hum before it gets into the signal circuitry.

Power factor correction

In electric power distribution, capacitors are used for power factor correction.

Signal coupling

Because capacitors pass AC but block DC signals (when charged up to the applied dc voltage), they are often used to

separate the AC and DC components of a signal. This method is known as AC coupling or "capacitive coupling".

Decoupling

A decoupling capacitor is a capacitor used to decouple one part of a circuit from another. Noise caused by other circuit

elements is shunted through the capacitor, reducing the effect they have on the rest of the circuit. It is most commonly

used between the power supply and ground. An alternative name is bypass capacitor as it is used to bypass the power

supply or other high impedance component of a circuit.

Noise filters and snubbers

When an inductive circuit is opened, the current through the inductance collapses quickly, creating a large voltage across

the open circuit of the switch or relay. If the inductance is large enough, the energy will generate a spark, causing the

contact points to oxidize, deteriorate, or sometimes weld together, or destroying a solid-state switch. A snubber capacitor

across the newly opened circuit creates a path for this impulse to bypass the contact points, thereby preserving their life;

these were commonly found in contact breaker ignition systems, for instance. Similarly, in smaller scale circuits, the spark

may not be enough to damage the switch but will still radiate undesirable radio frequency interference (RFI), which a

filter capacitor absorbs. Snubber capacitors are usually employed with a low-value resistor in series, to dissipate energy

and minimize RFI. Such resistor-capacitor combinations are available in a single package.

Motor starters

In single phase squirrel cage motors, the primary winding within the motor housing isn't capable of starting a rotational

motion on the rotor, but is capable of sustaining one. To start the motor, a secondary winding is used in series with a non-

polarized starting capacitor to introduce a lag in the sinusoidal current through the starting winding. When the secondary

winding is placed at an angle with respect to the primary winding, a rotating electric field is created. The force of the

rotational field is not constant, but is sufficient to start the rotor spinning.

Signal processing

The energy stored in a capacitor can be used to represent information, either in binary form, as in DRAMs, or in analogue

form, as in analog sampled filters and CCDs. Capacitors can be used in analog circuits as components of integrators or

more complex filters and in negative feedback loop stabilization. Signal processing circuits also use capacitors to integrate

a current signal.

Sensing

Most capacitors are designed to maintain a fixed physical structure. However, various factors can change the structure of

the capacitor; the resulting change in capacitance can be used to sense those factors.

Changing the dielectric:

The effects of varying the physical and/or electrical characteristics of the dielectric can also be of use. Capacitors with an

exposed and porous dielectric can be used to measure humidity in air. Capacitors are used to accurately measure the fuel

level in airplanes; as the fuel covers more of a pair of plates, the circuit capacitance increases.

Changing the distance between the plates:

Capacitors with a flexible plate can be used to measure strain or pressure. Industrial pressure transmitters used for process

control use pressure-sensing diagphragms, which form a capacitor plate of an oscillator circuit. Capacitors are used as the

sensor in condenser microphones, where one plate is moved by air pressure, relative to the fixed position of the other

plate. Some accelerometers use MEMS capacitors etched on a chip to measure the magnitude and direction of the

acceleration vector. They are used to detect changes in acceleration, eg. as tilt sensors or to detect free fall, as sensors

triggering airbag deployment, and in many other applications. Some fingerprint sensors use capacitors. Additionally, a

user can adjust the pitch of a theremin musical instrument by moving his hand since this changes the effective capacitance

between the user's hand and the antenna.

Changing the effective area of the plates:

Capacitive touch switches are now used on many consumer electronic products.


4


Diode Md. Abdul Motin, EEE-061005, RUET

Some elements are linear (resistors, capacitors, inductors), which means that doubling the applied signal (let us say a

voltage) produces a doubling of the response (let us say a current). They are also passive – they do not have built-in

source of power. They are two-terminal devices, (which is self-explanatory). Diode is also two-terminal, passive but non-

linear a device. Figure 1 shows the diode.

Fig.1. Diode. Fig.2. Diode voltage-current curve, U-I curve.

In Fig. 2 there is U-I (voltage-current) curve (characteristic). The diode arrow, anode terminal, shows the direction of

forward current flow. If the diode is in a circuit in which a current of 10mA=10*10-3

A is flowing from anode to cathode,

then the anode is approximately 0.5 volt more positive than cathode. We call it the forward voltage drop. The reverse

current is measured in nano ampers and 1nA=1*10-9

A. It is so small in comparison to mA, that can be neglected until we

reach the reverse breakdown voltage. Typically it is approximately 75V and normally we never subject a diode to voltage

large enough to cause reverse breakdown. Similarly, the forward voltage drop, which is about 0.5 or 0.8 V, is of little

concern. For these reasons we treat the diode as a good approximation of an ideal one-way conductor.

Commercially available diodes are described also by other important characteristics, e.g.: maximum forward current,

capacitance (measured in pF), leaking current, reverse recovery time (measured in nanoseconds, 0-2-4-5000).

Rectification

A rectifier changes ac (alternating current) to dc (direct current). This is the most important application of diodes. Diodes

are sometimes called rectifiers.

The basic circuit is shown in Fig. 3.

Fig.3. Half-wave rectifier.



The ac represents a source of ac voltage. It can be a

amplitude much larger than forward voltage drop, the output will look like it is shown in Fig. 4.

The process and the circuit we call a half-wave

shown a full-wave rectifier and Fig. 6 shows the voltage across the load. The small gaps across zero voltage occur

because of the forward voltage drop.

Fig.5. Full-wave bridge rectifier.

Power supply filtering

The rectified wave from Fig.6 is not good for application: it is dc only in the sense that it does not change polarity. But i

does not have constant value and has plenty of ripples i

smoothed out in order to obtained authentic direct current. This can be done by means of a low

in Fig. 7.

The full-wave bridge diodes prevent flow of current back out of capacitor. The capacitor is an energy storage element.

The energy stored in a capacitor is 2

1CUE =

J=Watt/sek. The capacitor value is chosen so that



The ac represents a source of ac voltage. It can be a transformer or just ac sine-wave power line. For sine


Fig.4. Voltage across Rload in Fig.3.

wave rectifier, because only half of the input waveform is used. In Fig. 5 is

and Fig. 6 shows the voltage across the load. The small gaps across zero voltage occur

Fig.6. Voltage across Rload in Fig.5.

The rectified wave from Fig.6 is not good for application: it is dc only in the sense that it does not change polarity. But i

does not have constant value and has plenty of ripples i.e. small waves or undulations (wave like forms). It has to be

smoothed out in order to obtained authentic direct current. This can be done by means of a low-

Fig.7. Full-wave bridge with RC filter.

idge diodes prevent flow of current back out of capacitor. The capacitor is an energy storage element.

2CU . For C in F (farads) and U in V (Volts), E comes out in J (jouls) and

or value is chosen so that f/R load 1>> , where f is the ripple frequency. For power line sine wave

5

wave power line. For sine-wave input, of


, because only half of the input waveform is used. In Fig. 5 is

and Fig. 6 shows the voltage across the load. The small gaps across zero voltage occur

The rectified wave from Fig.6 is not good for application: it is dc only in the sense that it does not change polarity. But it

.e. small waves or undulations (wave like forms). It has to be

-pass filter, which is shown

idge diodes prevent flow of current back out of capacitor. The capacitor is an energy storage element.

. For C in F (farads) and U in V (Volts), E comes out in J (jouls) and

, where f is the ripple frequency. For power line sine wave


6


it is 2*50Hz=100Hz. It allows to ensure small ripples, by making the time constant for discharge much longer than the

time between recharging (the capacitor is charging very quickly, while discharging is very slow).

It is quite easy to calculate the approximate ripple voltage (see Fig. 8). Let us assume that the load current stays constant

(it will, for small ripples). The load causes the capacitor to discharge somewhat between cycles. The capacitor will loose

some voltage, let us say U∆ . In this case, we have:

tC

IU ∆=∆ , (from

dt

dUCI = )

Fig.8. Power-supply ripple calculation.

Instead of t∆ we use f/1 or f/ 21 respectively for half-wave rectification and for full-wave rectification. Finally we

obtain approximate ripple voltage:

° for halve-wave fC

IU load=∆ ,

° for full-wave fC

IU load

2=∆ .

If one wanted to do exact calculation (with no approximation), one would use the exact exponential formula (see lecture

Capacitors, RC circuits). Sometimes it may be necessary. A dc power supply using the bridge circuit looks (in the USA)

as shown in Fig.9.

Fig.9. Bridge rectifier circuit. The curved electrode indicates a polarized capacitor, which must not be allowed the

opposite polarity.


7


Application of Diode:

Signal rectifier

If the input is not a sine wave, we usually do not think of it as a rectification in the sense as it was for power supply. For

instance, we might want to have a series of pulses corresponding to the rising edge of a square wave (see Figure, left hand

side and right hand side of the capacitor C). While both, the rising and the falling, pulses are in the output after

differentiation performed by CR circuit. The simplest way is to rectify the differentiated wave.

Figure: A series of pulses' rectifier.

We should remember about forward drop voltage of the diode: This circuit gives no output for signal for input smaller

then, forward drop voltage, let us say 0.5 V pp (peak to peak). If this is a problem, there are various tricks that help to

combat this limitation. For instance:

• use Schottky diodes with smaller forward drop voltage (approximately 0.2V),

• use so called circuit solution, which means modifying the circuit structure and compensating the drop,

• use matched-pair compensation, use transistors, FETs.

Diode gates

Another application of diode is to pass the higher of two voltages without affecting the lower. A good example is battery

backup, a method of keeping s device running (for instance a precision electronic clock) in case of power failure. Figure

shows a circuit that does the job.

Figure: Diode OR gate, battery backup.

[OR gate: The output of OR gate is HIGH if either input (or both) is HIGH. In general, gates can have any number of

inputs. The output is LOW only if all inputs are LOW].

The battery does nothing until the power fails. Then the battery takes over the control, without interruption.

Diode clamps

Sometimes it is necessary to limit the range of signal (for instance not to exceed certain voltage limit and not to destroy a

device). The circuit in Figure will accomplish this.



The diode prevents the output from exceeding

voltages. The only limitation is that the input must not be so negative that the reverse breakdown v

Diode clamps are the standard equipment on all inputs in the CMOS family of digital logic (Complementary Metal Oxide

Semiconductor). Without them, the delicate input circuits are easily destroyed by static electricity.

Limiter

The circuit in Figure limits the output swing

Fig

It might seem very small, but if the next device is an amplifier with large voltage amplification, its input has to be always

near zero voltage. Otherwise the output is in state of saturation. For instance we have an op amp with a gain of 1000. The

amplifier operates with supply voltage ±15V. Sometimes it can be

give output voltage bigger than the supply voltag

will saturate the output. This particular amplifier gives the output proportional to the input (proportionality factor is 100

only for input signals from the interval (-15mV,+15mV).

amplifiers.

Details of clippers, clampers, voltage multiplier, series parallel configuration of diode, zener diode will be explained in t

class.

Application of Relay:

• Control a high-voltage circuit with a low

audio amplifiers

• Control a high-Current circuit with a low

automobile



Figure: Diode voltage clamp.

The diode prevents the output from exceeding ≅ 5.6V, with no effect on voltages smaller than this, including negative

voltages. The only limitation is that the input must not be so negative that the reverse breakdown v



output swing to one diode drop, roughly 0.6V.

Figure: Diode limiter.


output is in state of saturation. For instance we have an op amp with a gain of 1000. The

15V. Sometimes it can be ±12V or ±18V or something in between. It will never

give output voltage bigger than the supply voltage, i.e. ±15V. It means that the input signal ±15mV (

will saturate the output. This particular amplifier gives the output proportional to the input (proportionality factor is 100

15mV,+15mV). This diode limiter is often used as input protection for high

Details of clippers, clampers, voltage multiplier, series parallel configuration of diode, zener diode will be explained in t

Relay Anisur Rahman, EEE-061016, RUET

voltage circuit with a low-voltage signal, as in some types of modems or

Current circuit with a low-current signal, as in the starter solenoid of an

8

5.6V, with no effect on voltages smaller than this, including negative

voltages. The only limitation is that the input must not be so negative that the reverse breakdown voltage is exceeded.




output is in state of saturation. For instance we have an op amp with a gain of 1000. The

18V or something in between. It will never

15mV (±15V/1000) or bigger

will saturate the output. This particular amplifier gives the output proportional to the input (proportionality factor is 1000)

This diode limiter is often used as input protection for high-gain

Details of clippers, clampers, voltage multiplier, series parallel configuration of diode, zener diode will be explained in the

or

of an


9


• Detect and isolate faults on transmission and distribution lines by opening

and closing circuit breakers (protection relays)

• Isolate the controlling circuit from the controlled circuit when the two are at

different potentials, for example when controlling a mains-powered device

from a low-voltage switch. The latter is often applied to control office

lighting as the low voltage wires are easily installed in partitions, which may

be often moved as needs change. They may also be controlled by room

occupancy detectors in an effort to conserve energy,

• Logic functions. For example, the boolean AND function is realised by connecting normally open relay contacts

in series, the OR function by connecting normally open contacts in parallel. The change-over or Form C contacts

perform the XOR (exclusive or) function. Similar functions for NAND and NOR are accomplished using

normally closed contacts. The Ladder programming language is often used for designing relay logic networks.

• Early computing. Before vacuum tubes and transistors, relays were used as logical elements in digital computers.

See ARRA (computer), Harvard Mark II, Zuse Z2, and Zuse Z3.

• Safety-critical logic. Because relays are much more resistant than semiconductors to nuclear radiation, they are

widely used in safety-critical logic, such as the control panels of radioactive waste-handling machinery.

• Time delay functions. Relays can be modified to delay opening or delay closing a set of contacts. A very short (a

fraction of a second) delay would use a copper disk between the armature and moving blade assembly. Current

flowing in the disk maintains magnetic field for a short time, lengthening release time. For a slightly longer (up to

a minute) delay, a dashpot is used. A dashpot is a piston filled with fluid that is allowed to escape slowly. The

time period can be varied by increasing or decreasing the flow rate. For longer time periods, a mechanical

clockwork timer is installed.

Transformer Jewel, EEE, RUET

Application of Transformer:

• A major application of transformers is to increase voltage

before transmitting electrical energy over long distances

through wires. Wires have resistance and so dissipate

electrical energy at a rate proportional to the square of the

current through the wire. By transforming electrical power to

a high-voltage (and therefore low-current) form for

transmission and back again afterward, transformers enable

economic transmission of power over long distances.

• Transformers are also used extensively in electronic products

to step down the supply voltage to a level suitable for the low

voltage circuits they contain. The transformer also electrically

isolates the end user from contact with the supply voltage.

• Signal and audio transformers are used to couple stages of

amplifiers and to match devices such as microphones and


10


record players to the input of amplifiers. When this is done to improve power transfer to a load, it is called

impedance matching. Audio transformers allowed telephone circuits to carry on a two-way conversation over a

single pair of wires.

• A Potential Transformer (PT) is a special instrument transformer designed to provide a precise voltage step-

down ratio for voltmeters measuring high power system voltages.

• A Current Transformer (CT) is another special instrument transformer designed to step down the current

through a power line to a safe level for an ammeter to measure.

• A Tesla Coil is a resonant, air-core, step-up transformer designed to produce very high AC voltages at high

frequency.

• A Scott-T transformer converts 3-φ power to 2-φ power and vice versa.

• A linear variable differential transformer, also known as an LVDT, is a distance measuring device. It has a

movable ferromagnetic core to vary the coupling between the excited primary and a pair of secondary’s.

Inductor Nura Alam, EEE-061050, RUET

Application of Inductor:

• Inductors are used extensively in analog circuits and signal processing. Inductors in conjunction with capacitors

and other components form tuned circuits which can emphasize or filter out specific signal frequencies.

Applications range from the use of large inductors in power supplies, which in conjunction with filter capacitors

remove residual hums known as the Mains hum or other fluctuations from the direct current output, to the small

inductance of the ferrite bead or torus installed around a cable to prevent radio frequency interference from being

transmitted down the wire. Smaller inductor/capacitor combinations provide tuned circuits used in radio reception

and broadcasting, for instance.

• Two (or more) inductors which have coupled magnetic flux form a transformer, which is a fundamental

component of every electric utility power grid. The efficiency of a transformer may decrease as the frequency

increases due to eddy currents in the core material and skin effect on the windings. Size of the core can be

decreased at higher frequencies and, for this reason, aircraft use 400 hertz alternating current rather than the usual

50 or 60 hertz, allowing a great saving in weight from the use of smaller transformers.

• An inductor is used as the energy storage device in some switched-mode power supplies. The inductor is

energized for a specific fraction of the regulator's switching frequency, and de-energized for the remainder of the

cycle. This energy transfer ratio determines the input-voltage to output-voltage ratio. This XL is used in

complement with an active semiconductor device to maintain very accurate voltage control.

• Inductors are also employed in electrical transmission systems, where they are used to depress voltages from

lightning strikes and to limit switching currents and fault current. In this field, they are more commonly referred

to as reactors.

Multimeter Mahbub, EEE-061017, RUET

Application of multimeter:

Contemporary multimeters can measure many quantities. The common ones are:

• Voltage in volts.

• Current in amperes.



• Resistance in ohms.

Additionally, multimeters may also measure:

• Capacitance in farads.

• Conductance in siemens.

• Decibels.

• Duty cycle as a percentage.

• Frequency in hertz

• Inductance in henrys

• Temperature in degrees Celsius or Fahrenheit

Digital multimeters may also include circuits for:

• Continuity that beeps when a circuit

• Diodes (measuring forward drop and/or polarity) and

Various sensors can be attached to multimeters to take measurements such as:

• Light level

• Acidity/Alkalinity(pH)

• Wind speed

• Relative humidity

Application of breadboard:

A breadboard is used to make up

temporary circuits for testing or

to try out an idea. No soldering is

required so it is easy to change

connections and replace

components. Parts will not be

damaged so they will be available

to re-use afterwards.

References.

[1]. (Online) http://www.vias.org/physics/bk4_04_04b.html

[2]. (Online) http://www.electronics-project

[3]. Introductory Circuit Analysis, 10th Edition

[4]. (Online) http://en.wikipedia.org/wiki/Transformer

[5]. (Online) http://www.allaboutcircuits.com/vol_2/chpt_9/7.html

[6]. (Online) http://en.wikipedia.org/wiki/Breadboard



ionally, multimeters may also measure:

Fahrenheit.

Digital multimeters may also include circuits for:

when a circuit conducts.

(measuring forward drop and/or polarity) and transistors (measuring current gain and other parameters)

rious sensors can be attached to multimeters to take measurements such as:

Breadboard Rofiqul Islam, EEE-061031, RUET

http://www.vias.org/physics/bk4_04_04b.html

project-design.com/LightDependentResistor.html

Introductory Circuit Analysis, 10th Edition by Robert L. Boylestad Prentice Hall 2002

http://en.wikipedia.org/wiki/Transformer

http://www.allaboutcircuits.com/vol_2/chpt_9/7.html

http://en.wikipedia.org/wiki/Breadboard

11

(measuring current gain and other parameters)



[7]. (Online) http://www.kpsec.freeuk.com/breadb.htm

[8]. (Online) http://en.wikipedia.org/wiki/Multimeter

[9]. The art of Electronics by Paul Horowitz

[10]. Basic Engineering Circuit Analysis

[11]. Teach Yourself Electricity & Electronics

[12]. Modern Dictionary of Electronics by Graf

[13]. Illustrated Dictionary of Electronics by Stan Gibilisco

Design Challenge: Design a Negative Power

Variable DC

Power Supply



http://www.kpsec.freeuk.com/breadb.htm

]. (Online) http://en.wikipedia.org/wiki/Multimeter

Teach Yourself Electricity & Electronics by Stan gibilisco

dern Dictionary of Electronics by Graf

[13]. Illustrated Dictionary of Electronics by Stan Gibilisco

r Supply From a Single Positive Supply.

Home Work

12

lecture 1

Documents

resistor capacitor

c capacitor

resistor power rating

application of capacitor

mica capacitor

power sources

power supplies

dc power supply