Tushar has a passion for electronics since his early childhood and he was destined to become an electronics engineer by profession. It all started back in 1976 when Tushar's uncle Mr. Mukesh Naik (a Technician working with Telephones company in Mumbai, India) introduced him to the wonderful world of electricals/electronics by giving him exposure to basically interesting circuits like "free power radio" and development tools like "mechano". Uncle's moral and technical support molded Tushar to what he is today. Tushar's major's is in Digital and Analog electronics and he has invested a good fortune in test and measurement equipment.
Some of Tushar's Successful Commercial Circuits
Tips for Electronics Hobbyists & Project Builders
Tools & Equipment Required To Start Assembly At Home
The Capacitor Color Code Chart
Tushar has been a visiting faculty to various coaching classes for Engineering Students and over the period of time he has taught more then 1000 electronics engineering students from Bombay University. Apart from being a Lecturer he was also active in being a "project guide" for the "final year projects" for the engineering students. Some of his guided projects are :
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Electronics Dashboard for a Car with Digital Readouts
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Elevator Control for Mines (trolley cars)
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Digital Integrated Circuit Tester
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Robot Buggy
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Remote Control of Household Equipment using Telephone
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Conveyor Control using PC
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Alarm Annunciator
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EPABX Telephone Switch Exchange
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Digital 3 1/2 Digit Multimeter
And many more........
Some of Tushar's Successful Commercial Circuits
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Automatic Tank Level Controller
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Automatic Audio Volume Controller for Stereo System
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Timer for Handheld Blender
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Digital Timer for Baking Ovens
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10-Channel Running Lights with Speed Controller
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2KW Halogen Light Dimmer
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General Purpose Karaoke circuit
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Noise Cancellation Circuit for Audio Equipments
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10-Channel Graphic Equalizer
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10-Channel Handheld Real Time Analyzer
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Electronic Motor Protection Relay
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Electronic Frequency Relay
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Electronic Over/Under Current Relay
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Electronic Over/Under Voltage Relay
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Phase Sequence Indicator
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Single Phase Preventor
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Auto Synchronizer for Two Gensets
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Washing Machine Controller
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Engine Order Telegraph for Ships
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Ship Navigation Light Controller
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Automatic Change Over Switch for Two Incoming Power Sources
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Discrete Alarm Annunciator
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Microcontroller based Alarm Annunciator
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Heavy Duty Programmable Flasher
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40-Way Multicore Cable Tester
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4-20mA Current Loop Injector & Tester
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0-30V, 3A Regulated Power Supply Modules
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100 Watts Invertor using 12VDC Car Battery
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Solid-state Voltage Stabilizer (without motorised Variac)
And Many More.....
Tips for Electronic Hobbyist & Project Builders
Tools and equipment required to start assembly at home
Some basic tools and equipment is necessary to start or convert your backyard into a hobbyist den :
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Screw drivers set (Philips type and standard)
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Nose pliers
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Tweezers
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Wire Stripper
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Cutter
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Crocodile Clips
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Soldering Iron (preferably from Goot)
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Good quality solder wire and flux
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Adjustable blades
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Files (small and big)
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3 1/2 Digit Multimeter
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Analog Multimeter
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Signal Injector (can be assembled at home)
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Old general purpose (full-range) speaker unit (without any enclosure)
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Pair of RCA and EP connecting cables
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Hacksaw
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Electric Drill Machine
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Measuring Tape
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Rubber Solution and some glue
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Nickel-gold platted terminals (RCA, Phone and Banana type)
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Multicolor thin gauge hook-up wire
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Breadboard (Wishboard)
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Adjustable Regulated Power Supply (0-30V, 2A)
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Basic building block components such as
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Assorted resistors (1/4 watt, +/-5% tolerance, carbon)
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Assorted ceramic disc capacitors (pF, nF, uF)
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Red, Green, Orange, Amber LEDs (3mm, 5mm & 10mm)
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Relays (1 NC, 1 NO) - 12VDC
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Transformers - 6-0-6V/500mA, 12-0-12V/500mA
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Toggle Switches - Single pole, Double pole
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Rocker Switches
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Push Switches
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Sockets - RCA, EP, Phone
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Pins (plugs) - RCA, EP, Phone
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Solenoid - 12 VDC
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Toy Motor - 12 VDC
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Integrated Circuits (IC, chips)
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Timer NE555
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Opamp LM741
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Counter CD4017 & CD 4060
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Counter 74LS93
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Voltage Regulator 7805
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Voltage Regulator 7809
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Voltage Regulator 7815
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Multiplexor 74LS154
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Flip-flop CD 4027
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Audio Power Amplifier TBA810
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Transistors
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BC148
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BC149
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BF198
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SL100
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SK100
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BD139
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BD140
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2N3055
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2N2955
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Diodes
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1N4001
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1N4148
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6A4
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OP64
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The first thing that an electronics hobbyist must do is to learn the Ohm's law (ie. V = I x R, Voltage is the product of Current flowing through a resistor)
Then the next stage is to learn how to identify components and to read their values by looking at the color code or the number printed on those passive components like resistors, capacitors and inductors.
The Resistor Color Code Chart
The resistor color code is a industry standard in recognizing the value of resistance of a resistor. Each color band represents a number and the order of the color band will represent a number value.
The first two color bands indicate a number. The third color band
indicates the multiplier or in other words the number of zeros. The
fourth band indicates the tolerance of the resistor +/- 5, 10 or 20 %.
| COLOR | 1ST. DIGIT | 2ND. DIGIT | MULTIPLIER | TOLERANCE | HOW TO REMEMBER
THE COLOR CODE |
|---|---|---|---|---|---|
| Black | 0 | 0 | 1 | BAD | |
| Brown | 1 | 1 | 10 | BEER | |
| Red | 2 | 2 | 100 | ROTS | |
| Orange | 3 | 3 | 1,000 | OUR | |
| Yellow | 4 | 4 | 10,000 | YOUNG | |
| Green | 5 | 5 | 100,000 | GUTS | |
| Blue | 6 | 6 | 1,000,000 | BUT | |
| Violet | 7 | 7 | 10,000,000 | VODKA | |
| Gray | 8 | 8 | 100,000.000 | GOES | |
| White | 9 | 9 | 1,000,000,000 | WELL | |
| Gold | 5% | GET | |||
| Silver | 10% | SMASHED | |||
| No Color | 20% | NOW |
Example: Red-Red-Orange-Gold = 22,000 ohms, 5%
Connecting two resistors or inductors in parallel reduces the overall effective resistance or inductance value, whereas connecting two resistors or inductors in series increases the overall effective resistance or inductance value.
R = R1 + R2 (R = Overall Effective Resistance value, R1 & R2 are two resistors in series)
1/R = 1/R1 + 1/R2 (R = Overall Effective Resistance value, R1 & R2 are two resistors in parallel)
Connecting two capacitors in parallel increases the overall effective capacitance value, whereas connecting two capacitors in series decreases the overall effective capacitance value.
C = C1 + C2 (C = Overall Effective Capacitance value, C1 & C2 are two capacitors in parallel)
1/C = 1/C1 + 1/C2 (C = Overall Effective Capacitance value, C1 & C2 are two capacitors in series)
| CERAMIC DISC CAPACITORS: | ||||||
| Usual | M | K | J | D | C | |
| Tolerances: | +/- 20% | +/- 10% | +/- 5% | +/- .5% | +/- .25 pF | |
| RULE: | EXAMPLES: | |||||
| Usually value is 3 digits: | Stamped: | Value (in pF): | Value (in uF): | |||
| Digits one and two represent | 1R0 | 1 | 0.000001 | |||
| the starting value. Digit three | 1R5 | 1.5 | 0.0000015 | |||
| represents the number of | 100 | 10 | 0.00001 | |||
| zero's after the starting value: | 101 | 100 | 0.0001 | |||
| 102 | 1000 | 0.001 | ||||
| 1 | O | 683 | 68000 | 0.068 | ||
| 2 | OO | 471 | 470 | 0.00047 | ||
| 3 | OOO | 472 | 4700 | 0.0047 | ||
| 4 | OOOO | 334 | 330000 | 0.000033 | ||
|
NOTE:
R is a special designator depicting the location of a decimal
point. The first and third number (if even placed on the cap) simply are placed around the decimal point as shown above. |
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| FILM CAPACITORS: | ||||||
| Usual | M | K | J | G | F | |
| Tolerances: | +/- 20% | +/- 10% | +/- 5% | +/- 2% | +/- 1% | |
| NOTE: The three digit rule is the same for film capacitors as for disk capacitors. | ||||||
| ELECTROLYTIC CAPACITORS: | ||||||
| NOTE: These capacitors are usually large enough to have their values and tolerances printed right on them. | ||||||
| OTHER CAPACITORS: | ||||||
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NOTE:
Other capacitors, such as Dip
Tantalum, Polyester Box, etc. have either a color code
(discussed next) or a value on them which directly spells out
their value or can be deciphered using the above
chart.
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After the hobbyist makes himself acquainted with the basic laws and the components, then he can start building some basic functional blocks such as a Flasher or a Touch switch using NE555 or a Clap switch using LM741 and CD 4027. Such circuits are freely available at various websites (you can also reach some of these websites from my favorite links page).