APPLICATIONS OFELECTRONICS : APPLICATIONS OFELECTRONICS
Slide 2 : Beauty of Electronics
Sophistication in miniaturization
If you know it then you are a doctor and if you don’t then you are a patient
Datasheets are boons for dealing with any component or IC, you are unaware of
Most versatile in technological applications- a single IC can sometimes perform hundreds of different operations
A driving force of few watts controls the activities of the giants
- Machinery, automobiles, all household appliances,
whole communication system, automization, defense,
weaponry and many more damn things….
Slide 3 : BASIC DEVELOPMENT TOOLS
Breadboard
Multimeter
PCB, ECB
Slide 4 : Resistances
a) Fixed
- carbon
- wire wound
Slide 5 : b) Variable
- Rheostat, Pot, Preset
App. – tuning, voltage curves,
voltage dividers
--Photoresistors (LDRs), thermistors
App. – sensors, safety devices,
volume
Slide 6 : Capacitors
- polarised (electrolytic, tantalum)
- unpolarised (small value)
App.- storing elec. energy,
filters, timing circuits
-- Variable (very small value)
App.- radio tuning ckts
-- Trimmers (like presets)
Slide 7 : Diodes
( conduct in one dir)
Switching- (p-n junc)
App.- switch, rectification
Schottky- (M-SC contact)
App.- high speed switching,
RF, low loss rectifier
Zener- (rev breakdown)
App.- vol reg, safety ckts
Slide 8 : Photo (rev current increases linearly)
App.- solar cells, photometry,
auto lighting, camera
Laser- in optical devices and
disco lights
LEDs- (emits light in FB)
App.- opto-isolator with photo
diodes, sensors, lighting,
power status, flash
Tunnel, point contact, step recovery,
varicap, pin, crystal, avalanche, gunn,
peltier, clamping, welding….
Slide 9 : Transistors- (building blocks of circuitry)
App.- amplification, switching,
all ICs and productive ckts,
super beta, high vol, audio….
-- BJT, FET (JFET, MOSFET),
unijunc, avalanche, photo,
darlington, alloy junc….
BJT- (majority/minority carriers,
E-B-C, two p-n junc, current
operated, NPN-PNP)
Slide 10 : VHF-UHF (2N3866/4427)
Si-NPN, TO-39, low power
Small Signal (BC-327/328,
BC-556/57/58/59/60)
Si-PNP, TO-92, switching, amplification
General purpose (BC-546/7/8)
Si-NPN,TO-92, amplifier, 625 mW
SL/CL-100 (TO-39)
Slide 11 : - FET- (unipolar, n/p-channel, S-G-D)
a) JFETS b) MOSFETS
App.- precision, comp logic,
Digi ICs, MUXing
Phototransistors- photodetector, camera,
cd players, VCRs, TV
- Darlington/array- huge amplification,
buffering, motor drivers,
touch sensitive switch
Slide 12 : - Some ckt app. Biasing cascading tuned amp power amp multivibrator
Slide 13 : TRANSFORMERS
generally for step-down from AC-mains
to 18/12/9/6 V etc.
- current rating is important
LINEAR ICs : LINEAR ICs - Amplifiers- for increasing voltage or power
(audio, video, radio freq, wide band, differential)
Op-Amps (high gain voltage amp)
- LM-741 (mono op-amp, 8 pin)
- LM-158/258/358/2904 (low power dual op-amp, 8 pin)
- LM-124/224/324 (low power quad op-amp, 14 pin)
Slide 15 : - Applications- diff. amp, oscillator, voltage follower, inverter,
adder, subtractor, AC vol amp, rectifiers, peak detector,
clipper, clamper, S/H, comparator, multiplier/divider,
differentiator/integrator, zero crossing detector, phase
detector, schmitt trigger, square/triangular/sine wave
generator…
Slide 16 : 555 Timer (TO-99 can or 8 pin mini DIP)
Generates accurate time delay and oscillation
a) astable b) monostable c) bistable
App.- power on delay in appliances, oscillator, pulse/ramp/square wave generator, traffic light control,
burglar alarm, timed-bombs, missing pulse detector,
frequency divider, PWM, FSK generator, PPM, schmitt trigger, lifts…..
Slide 17 : Voltage Regulator
zener, op-amp, SCR, 78XX, 723, 317, switching
78XX/79XX (TO-3 metal, TO-220 plastic)
XX=05,06,08,12,15,18,24
-2 and -5.2 too in 79XX
App.- fixed series regulation, adjustable reg,double voltage supply, IC supplies, precision meters
Slide 18 : 723 (14 pin DIP, 10 pin metal can)
App.- general purpose, low/high voltage reg, appliances
Switching- (2653, 2727, 64 42)-by PWM (duty cycle)
high power eff, even higher voltage than i/p, opp polarity too
App.- portable comps
Slide 19 : ADC- converts analog signal to several line/bit digital value
- ADC 0803/04- (CMOS 8 bit, 20 pin,5v, 100 microsec., microP compatible, 0-5 v range)
- AD 7824/28- (4/8 analog channel, Linear Compatible CMOS high speed, 8 bit,24/28 pin 5v, 2.5 microsec/channel)
- App.- microprocessor interface, interfacing linear ckts, digital meters/displays, sensor ckts……
Slide 20 : Common ckts
Slide 21 : DAC- converts several line digital value to analog equivalent
AD7524- (8 bit, 100 ns settling time, 80 ns prop delay)
0830/1/2- (CMOS, 8 bit, double buffered, 1 microsec sett time)
App.- audio players, sound cards, video, computer interface
SENSORS : SENSORS LIGHT- LED, laser, LDR, photo transistors/diodes
LDR- resistance varies with intensity of light hence gives
variable output voltage in the ckt which is tracked for
sensing purposes- led, lasers are light sources
App.- burglar alarms, robotics, light operated clocks, shadow
detector, automatic lighting, dimmer, LCDs, mobiles
Slide 23 : IR- IR led, TSOP 17XX, PIR, pyroelectric
- TSOP 1730/36/38/56- (receiver- photodetector+preamplifier,
-0.3-6 v, 1200 bits/sec data transmission)
- Passive IR (PIR)- measure IR light radiated from objects in field of view
- Pyroelectric- (IRA-E700/900/940)- highly sensitive
- App.- motion detector, burglar alarms, remote thermometer,
night vision, IR camera, surveillance/monitoring, diagnostics
Slide 24 : Temperature- thermistor, AD590, LM335
- AD590- constant current source dependent on temperature
- LM135/235/335- precision sensors, 2 terminal zener, brekdown
voltage proportional to temp, -40 to 150 deg C
- App.- appliances, overheat protection, fire alarms,
Slide 25 : Pressure- diaphragm, liquid level, gauge
- pressure transduced into electrical quantity
- variable capacitance- one plate is diaphragm of sensor
- piezoresistive- piezoresistive strain induces voltage
- App.- pressure sensing, altitude sensing, density, weighing machines, impact sensing, security, lifts
Switches : Switches - Binary devices which interrupt the flow of electrons in a ckt
by any physical or chemical process
- Limit- (machine motion operated switch)- lever actuator,
proximity (energised by moving magnet), optical
Slide 27 : - Process- pressure (gas/liquid-piston/diaphragm), speed (rotory speed of shaft), temperature (bimetallic, brass bulb) , liquid level, liquid flow, tilt (mercury), reed (magnetic field)
Slide 28 : Hand- rocker, toggle, pushbutton, slide, joystic, tact, DIP,
snap action, rotary, key lock, navigation, leaf
Slide 29 : - Pole- no. of contacts/levers
- Throw- no. of contact positions/ways/switching positions
break before make make before break
Applications- ckts, robotics, machines, alarms, all industries/
appliances, automatic/property controlled switching, robotic
toys, multiple/secure/compact/easy switching, changers…..
Slide 30 : Relays- solenoid is used to actuate a set of switch contacts
- controls a large amount of current and/or voltage with small electrical signal
- acts as binary amp (controls one electrical signal with other)
- coil and contact ckts are electrically isolated
- pull in current- min current for actuation
- drop out current- max current at which
contacts come in normal state
Slide 31 : Latching (bistable states)
Contactor (electric motors starter)
Reed (contact in gas tube- no corrosion)
Mercury wetted (no bounce),
Solid state (no movables – SCR, opto triac - optically coupled)
Overload protection (bimetallic)
Time delay (shock absorber attached to armature by pneumatic dashpots/fluid filled piston/RC ckts)
Slide 32 : - App.- automatic switches/changers, telephone exchange,
industries, protection, electronic ckts, interfacing, decoupled
ckts interaction….
DIGITAL ICS : DIGITAL ICS - Bit (binary digit)- two discrete values for more reliability (0-1)
- Codes- BCD(8421), 84-2-1, 2421, excess 3, biquinary (5043210)
Binary logic follows boolean algebra and represented by truth tables
Three basic operations- AND, OR, NOT
Digital IC types-
SSI- few gates, basic logic operations
MSI- 10-100 gates, performs complete logic function
LSI- more than 100 gates
VLSI- thousands of gates
Slide 34 : Gates
Slide 35 : Decoders/demultiplexers – combinational ckt which converts n bit binary information to one of 2^n unique outputs
- demux is a decoder with an enable input
- 3-8 line- 7411238, 74138
- 4-16 line- 74154, 744514, 74159
- dual 2-4 line- 74139
- bcd-decimal- 7442 ……………..
Slide 36 :
Slide 37 : Encoder – MUX/Data Selectors- reverse of decoder
2^n – n line, IC packages- priority encoder
- Multiplexing- transmitting large no. of information units over
smaller no. of lines
- 74147 - 10 line decimal to 4 line bcd
- 74148, 4532 B - 8 data lines to 3 lines binary
- 74157 - quad 2 line to 1 line MUX
Slide 38 : - App.- code conversion, interfacing, selecting lines from a ckt,
electronic locks, ROM (decoder + programmed Ors ), buses,
BCD – 7 Segment display driver/decoder
CD 4511 and 7447
Computer design : Computer design - Digital Computer is a discrete information processing system
- discrete elements of information are represented by signals
- two (binary) discrete values- 0/1
Gates < adders/decoders/MUX/ROM/PLA/binary cells
(flip flops/ferrite cores/punched cards) < registers/counters < memory/ALU/CU/processors < CPU < digital/microcomputer
Sequential logic-
Memory
ALU
Micro-processors
Micro-controllers/PIC
Latke-jhatke : Latke-jhatke Darlingtons
Thyristors (SCR), diac, triac
Varicaps
Digital thermometer