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EFY’s Most Popular EE Projects Part 1 [Soft Copy]

by DANV
Save Rs. 180.00
Rs. 299.00
Rs. 119.00
Featuring 11 awesome electrical engineering projects, this 45-page e-book, provides electrical engineers a chance to get their hands dirty and brains working on fascinating projects.
These projects will test your knowledge of various concepts of electrical and electronics engineering.
So pick one now.
Check out product images to get an idea of the projects in the book.
Check out our electrical project part 2 

Learning

  • Application of different IC's like NE555, CD4060, CD4047 multivibrator, audio amplifier etc.
  • Application LED, IR LED, Variable resistor and capacitor, inductor.
  • Use of breadboard, perfboard & PCB.
  • Application of transistor as amplifier and switch.
  • Use of different kinds of switches

Table of contents:

  1. Water Pump Dry Run Guard
  2. Arduino-Based-Smartphone-Controlled Robot Car
  3. Stereo Amplifier Using TDA7052 ICs For Portable Devices
  4. Computerized Universal Timer
  5. 1kW Sine Wave Inverter
  6. PIN Diode Based Fire Sensor
  7. Low-Cost Dusk-Dawn Controller
  8. Programmable On And Off Controller For 3-Phase Motor
  9. Countdown Timer
  10. PROTECTION FOR YOUR ELECTRICAL APPLIANCES 
  11. Over-/Under-Voltage Protection Of Electrical Appliances
School/College Quiz Buzzer Save Rs. 200.00
Rs. 750.00
Rs. 550.00

School/College Quiz Buzzer

School/College Quiz Buzzer

by KNS Pvt Ltd
Save Rs. 200.00
Rs. 750.00
Rs. 550.00

Summary

Manual buzzers used for quiz competitions in schools and colleges create a lot of confusion in identifying the first respondent. Although there are circuits using PCs and discrete ICs, they are either too expensive or limited to only a few number of players. The School/College Buzzer is a circuit that can be used for up to eight players.It uses the IC 74LS373 (which is an octal latch) and a few passive components to implement the quiz buzzer mechanism.

Learning

Things Which you will learn:
*Application of the octal latch IC 74LS3737.
*Use of SCRs in logic circuits.
*Application of transistors as switches.

Product Description

Quiz competition is an integral part of our learning and as the world advances towards technological advancement, there should be some changes in the way we conduct a quiz. So with this kit, you can build yourself a digital quiz buzzer supporting upto eight players and enjoy playing quiz without any confusion.

 

Working

At the heart of the School/College, Quiz Buzzer is the IC 74LS373 which transfers the logic state at data input pins (D0 through D7) to the corresponding outputs (Q0 through Q7). Data pins D0 through D7 are normally pulled low by resistors. One terminal of eight push-to-on switches (S1 through S8) is connected to +5V, while the other terminal is connected to the respective data input pins. The switches are to be extended to the players through cord wire.

The torch bulbs (BL1 through BL8) can be housed in boxes with the front side of the boxes covered with a white paper having the name or number of the contestant written over it for easy identification. When the power is switched on using switch S9 (provided terminals ‘A’ and ‘B’ of both the power supply and quiz buzzer sections are interconnected), the circuit is ready to be used.

Now all the switches (S1 through S8) are open and Q0 through Q7 outputs of IC 74LS373 (IC2) are low. As a result, the gates of silicon-controlled rectifiers (SCR1 through SCR8) are also low. As soon as a contestant momentarily presses his respective switch, the corresponding output data pin goes high.

This triggers the corresponding SCR and the respective bulb glows. At the same time, the piezoelectric buzzer (PZ1) sounds as transistor BC548 (T1) conducts. Simultaneously, the base of transistor BC548 (T2) becomes high to make it conduct. Latch-enable (LE) pin 11 of IC2 is tied to ground to latch all the Q0 through Q7 outputs. This restricts further change in the output state due to any change in the state of switches S1 through S8 by any other contestant.

Only one of the eight torch bulbs glows until the circuit is reset by on/off switch S9.

 

Download PDF for this project.

Summary

Electronics Field is very vast and for those who want to enter this segment in a systematic step by step method, the CHIP TALK offers the best platform where it provides basics of all the necessary concepts required to build projects and moreover it comes with a 40 tested projects circuits to boost your confidence in building and enjoying the projects.
CHIP-TALK Hobby Projects package includes components and breadboard for prototyping 40 fully tested projects. The book contains the fundamentals of electronics and 40 tested circuits and their descriptions.

Learning

Things which you can learn:

*Applications of different ICs like CD4011, CD4001, NE555, op amp etc.
*Application LED, IR LED, Variable resistor and capacitor, inductor.
*Application of L14F1.
*Application of ultrasonic transmitter and receiver.
*Use of breadboard.
*Application of transistor as amplifier and switch.
*Use of different switches like DPDT, SPDT, SPST.
*Use of relay.

Product Description

An Awesome platform for those who are looking to build and learn electronics project with easy access to all the circuits and necessary informations supporting the project.

CHIP-TALK Hobby Projects package includes components and breadboard for prototyping 40 fully tested projects. The book contains the fundamentals of electronics and 40 tested circuits and their descriptions. Below is the list of projects:

1.Circuit Symbols & conventions
2.Basic Tools and Test Equipment
Hand tools
Multimeter
Logic Probe
Trimming tool set.
3.Soldering/de-soldering equipment
SOLDERING TIPS
4.Safety precaution for preventing electric shock
5.Ohm’s law
6.Fixed and Variable Resistors
Resistor Colour code and conventions
Naming Convention.
The E12 Range
The E24 Range
Simplifying The Color Code
Resistor wattage
7.Capacitors and capacitive reactance.
Colour coding and marking schemes for fixed capacitors
IEC letter and digit code for r & c values
Conversion table for capacitance values
8.Inductors (coils) and inductive reactance
9.Circuit assembly
Breadboard.
Stripboard
Printed Circuit Board
10.Illustrations of some commonly used components
Tactile switch
Loudspeaker
Piezo Buzzer
Diodes
Light Emitting Diode (LED)
7-Segment LED display
DIL/DIP switch
SIL/SIP RNW
11.Stabilized Power-supply
12. Versatile TTL/CMOS Logic and Clock Probe

Part II
Section 1

12.UM66TXXX Melody generator-based projects
General Description
XXX suffix

13.Project 1. A simple melody player
14.Project 2. Melody player using speaker
Modifications UM66TXXS (single shot)
15.Project 3. Musical call bell
16.Project 4. Musical hold-on for Telephone
17.Project 5. Timer with Musical Alarm
18.Project 6.Intercom with Musical Ringtone
19.Project 7. Soft Musical Telephone Ringer
20.Project 8. Touch-sensitive Musical Bell with delay
21.Project 9. Musical Continuity Tester

Section 2

22. TTL and CMOS logic based circuits
Noise immunity
Fan-out
Propagation delay
Power requirements
Comparison. (CMOS VS TTL)
23. CD4011 quad 2-input NAND gate to realize:
Inverter. Or Not gate
AND gate
OR gate
NOR gate
XOR gate
24. NAND gate(s) based circuits
Project 10. A set-reset (Bi-stable) flip flop
Project 11. Touch Sensitive Alarm
Project 12. On/off Ringer
Project 13. Toilet Busy Indicator
Project 14. Electronic Direction Pointer
Project 15. Simple Soil Moisture level Controller
Project 16. Touch Sensitive Single-chip Flasher-cum-beeper
Project 17. Automatic Pump Controller
Project 18. Generating Three Tones Using a Single digital IC

Section 3

25. Timers and Counters
555 Timer and 556 dual Timer
Monostable mode (555 timer)
Astable mode (555 timer)
CD4017 counter
CD4026B and CD4033B Counters
26. Timer and counter based circuits
Project 19. Divide-by-N counter using CD4033
Project 19A. Divide-by-2 through 6 and 8 (using CD4033)

Project 19B. Divide-by-7 counter (using CD4033)
Project 19C. Divide-by-9 counter (using CD4033)
Project 20. Divide-By-N Counter Realization
Using 555, CD4033 And CD4017
Project 21. Telephone Call Counter
Project 22. Mains Interruption Counter with Indicator
Project 23. Timer For Students
Project 24. DICE with 7-segment display

Section 4

Project 25. Simple smoke Alarm
Project 26. Concealed AC mains line detector.
Project 27. Speed Control Of Dc Motor Using Pulse-Width Modulation.
Project 28. IR to RF Converter.
Project 29. Contactless Telephone Ringer.
Project 30. Preamplifier (signal booster) for FM Band.
Project 31. Condenser mike Amplifier.
Project 32. Cordless F. M Mike.
Project 33. Laser Controlled On/Off Switch
Project 34. Phone broadcaster
Project 35. Anti-theft Alarm.
Project 36. Touch Dimmer.
Project 37. Doorbell using UM3561
Project 38. Poor man’s Miniature hearing Aid.
Project 39. Line-powered two-tone ringer.
Project 40. Ding-Dong Bell.
Project 41. Rechargeable White LED Torch

FM Booster Save Rs. 25.00
Rs. 125.00
Rs. 100.00

FM Booster

FM Booster

by KNS Pvt Ltd
Save Rs. 25.00
Rs. 125.00
Rs. 100.00

Summary

FM booster is a low-cost circuit that can be fed between an FM receiver and antenna to listen to distant commercial FM stations clearly.The main components of the circuit comprise of CS2570 transistor, trimmers and inductor coils.

Learning

Things which you can learn:
*Application of C2570 transistor.
*Working of trimmers.
*Maximum Power Transmission
*RF pre amplifier setup.

Product Description

The FM booster can be used to listen to programs from distant FM stations clearly It basically extends the range by which distant channels can be received.

Working

The circuit comprises a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570.

The input/output trimmers (VC1/VC2) for a set for maximum gain. An input coil L1 consisting of four turns of 20SWG enameled copper wire (slightly space wound) over 5mm diameter former, is tapped at the first turn from the ground lead side. Coil L2 is similar to L1 but has only three turns.

Click To View Circuit Diagram

Click here to Download PDF

Periodically On Off Mosquito Repellent Save Rs. 20.00

Periodically On Off Mosquito Repellent

by KNS Pvt Ltd
Save Rs. 20.00
Rs. 119.99
Rs. 99.99

Summary

Some of the mosquito repellents available in the market use a toxic liquid to generate poisonous vapors in order to repel mosquitoes out of the room. Due to the continuous release of poisonous vapors into the room, after midnight the natural balance of the air composition for good health reaches or exceeds the critical level.

Mostly, these vapors attack the brain through the lungs and exert an anesthetic effect on mosquitoes as well as other living beings by small or greater percentage. Long exposure to these toxic vapors may cause neurological or related problems.Here is a circuit that automatically switches on and off the mosquito repellent after a preset time interval, thus controlling the release of toxic vapors into the room.

Learning

Things which you can learn:

*Application of NE 555 timer.
*Application of TRIAC BT136.
*Application of Zener diode as a voltage regulator.

Product Description

Here is a circuit that automatically switches on and off the mosquito repellent after the preset time interval, thus controlling the release of toxic vapours into the room. The circuit turns the mosquito repellent ‘on’ for approximately 20 minutes then process of 'on' and 'off' occurs repeatedly.So if you leave the mosquito repellent switched on from 10 pm to 6 am (eight hours), it will be ‘on’ for four hours and ‘off’ for four hours of the total duration. During ‘off’ time, the room air tries to balance its natural composition.

Another important feature is that the circuit switches to ‘on’/‘off’ operation without producing any noise or a sound click as in a relay and hence doesn’t disturb your sleep.

Working

The circuit consists of a timer section built around IC 555 (IC1) and an automatic switching section using Triac BT136 (triac1). Power supply to the circuit is derived from the AC mains by stepping it down to a required level and rectifying it. The elimination of the transformer saves on space as well as money. Zener diode ZD1 and capacitor C2 provide regulated 9V DC power supply to timer IC1.The timer section comprises resistors R1 and R2 and capacitor C1.

The output of timer IC 555 is fed to the gate terminal of BT136 through series LED1 and resistor R4. When the timer output goes high, it triggers the gate of Triac 1 and LED1 shows the ‘on’ period. During ‘off’ time, the output of IC1 goes low and hence Triac 1 is not fired and LED1 doesn’t glow. The circuit is very compact and can be assembled on a general-purpose PCB. Use an 8-pin IC base for timer IC LM555. After assembly, fit the unit inside the housing electric board where you plug in the mosquito repellent.

 

Click here to Download PDF

 

Simple Projects You Can Make At Home Save Rs. 100.00

Simple Projects You Can Make At Home

by KNS Pvt Ltd
Save Rs. 100.00
Rs. 300.00
Rs. 200.00

Summary

This book on home projects may be of interest if you are studying electronics, or if you are a hobbyist or a beginner and wish to learn electronics in a practical way. The projects in this book explain the working and construction of various circuits, which can be easily assembled at home with few basic tools. These projects are basically for domestic as well as hobby applications. However, some of these projects may also be found useful in industrial applications.

The book is divided into five sections Alarm, Controller and Indicator, Display and Lighting, Timer and Clock and Game. The Alarm section contains seven projects covering various alarm circuits including Electronic Bell System, Multichannel Fire Alarm System, etc. Some of these circuits can be used at homes as well as industrial buildings. The controller and indicator section contains twenty-four projects covering circuits like Digital Water-Level Indicator-cum-Pump Controller, DTMF Remote Control System, Long-Range Remote Control, etc. The Display and Lighting section contains eight projects including Economical UPS for Cordless Phones, Multi-Feature Emergency Light, Multilingual Numerical Display, etc. The Timer and Clock section contains twelve projects including Digital Clock with Seconds and Alarm Time Display, Programmable Digital Timer-cum-Clock, LED Analogue Clock, etc.

The Game section is specially included here for the students and beginners with the aim to encourage them to learn electronics while they play. It contains nine projects including, A Mighty Gadget with Multiple Applications, Digital Number Shooting Game, Electronic Housie Player, Video Car-Racing Game, The Mind Reader, etc.

Product Description

TABLE OF CONTENTS


ALARM CIRCUITS

• Electronic Bell System
• All In One Alarm
• Multichannel Fire Alarm System
• Fire Sensing System
• 12 Tune Musical Door Bell
• Burglar Alarm to Protect Your Home
• Auto Shut Off Door Lock Alarm


CONTROLLER AND INDICATOR CIRCUITS

• Digital Water Level Indicator Cum Pump Controller
• Ultrasonic Lamp Brightness Controller
• Sound Operated On Off Switch
• Remote Controlled Sophisticated Electronic Code Lock
• DTMF 8 Channel Switching Via Powerline
• DTMF Remote Control System
• Automatic Room Light Controller
• A Unique Liquid Level Indicator
• Intelligent Water Level Controller
• Automatic Submersible Pump Controller
• Tripping Sequence Recorder Cum Indicator
• Electrolysis Proof Complete Water Level Solution
• Long Range Remote Control
• Remote Controlled Switch Board
• Multiple Control Remote Switch
• Infrared Remote Control
• Auto Changing In out Indicator with Door Bell
• Safety Indicators and AIDS
• Watchdog For Your Mains
• Auto Protection For Refrigerator
• Clap Operated Remote Control For Fans
• Refrigerator Temperature Controller
• A Volunteer in the Kitchen
• A Day Indicator With Alphabetical Display


DISPLAY AND LIGHTING CIRCUITS

• Economical UPS For Cordless Phones
• Multi Feature Emergency Light
• Novel Mains Running Lights
• Spectacular Spectra
• Dynamic Psychedelic Lights
• Multilingual Numerical Display
• Electronic Advertisement Display
• Make Yourself This Beeper Cum Flasher


TIMER AND CLOCK CIRCUITS

• Digital Clock Using Discrete ICs
• Digital Clock With Seconds And Alarm Time Display
• Simple Digital Clock With Hourly Music
• Digital Dial Clock
• Programmable Digital Timer Cum Clock
• Revolving Seconds Display
• Kettle Timer
• Melodious Digital Timepiece
• Improve Your Digital Clock
• Add Hourly Chime To Your Digital Clock
• LED Analogue Clock
• Make Yourself This Crystal-Controlled Electronic Digital Clock

GAME BASED PROJECTS

• MGMA A Mighty Gadget With Multiple Applications
• Digital Number Shooting Game
• Party Game How Old Are You?
• Electronics Housie Player
• Digital Scoreboard
• Yoka Fun Box
• Video Car-Racing Game
• Make Yourself The Mind Reader - An Interesting Game
• Make Yourself This Digital Birth Date Teller As a Party Game

Open Source India T-Shirts | Free Shipping

Get OSI T-Shirts for just Rs 999 (all included). 

The fabric is 260 gsm, 100% Cotton Fabric, Super Combed, Solid Polo and gives utmost comfort during all temperatures. Elegant stitch, white tipping, and Solid colours make this T-shirt a perfect Casual wear to pair with Jeans or trousers for a trendy look.

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Quality FM Transmitter Save Rs. 100.00
Rs. 300.00
Rs. 200.00

Quality FM Transmitter

Quality FM Transmitter

by KNS Pvt Ltd
Save Rs. 100.00
Rs. 300.00
Rs. 200.00

Summary

The digital like sound quality that FM offers is the reason that many people prefer to have their own transmitting station in FM band. The Quality FM Transmitter can transmit a chosen music piece in the FM band. To receive its signals, any conventional FM radio receiver can be used. It provides an easy way to transmit less distorted, low noise music with in a range of about 200 meters.

Just build yourself a simple FM transmitter, plug in the input via mobile or any other source and off you go with your own radio channel.Sounds exciting right !!

Learning

Things which you can learn:
*Application of transistor as amplifier.
*Working of variable resistor and trimmers.
*Concept and implementation of VHF using LC tuning Circuit
*Concept and implementation of Frequency modulation and antenna matching network
*Gain and maximum power transmission

Product Description

The Quality FM Transmitter provides good signal strength up to a distance of 500meters with a power output of about 200 mW. It works off a 9V battery. The input to the transmitter can be given by various sources like mobile phones, mp3 players etc.

Working

The audio-frequency modulation stage is built around transistor BF494 (T1), which is wired as a VHF oscillator and modulates the audio signal present at the base. Using preset VR1, one can adjust the audio signal level. The VHF frequency is decided by coil L1 and variable capacitor VC1. By reducing the value of VR2, a greater power output can be achieved. The next stage is built around transistor BC548 (T2), which serves as a Class-A power amplifier. This stage is inductively coupled to the audio-frequency modulation stage. The antenna matching network consists of variable capacitor VC2 and capacitor C9. By adjusting VC2, maximum power transmission and signal strength can be attained at the receiver end.

Click To View Circuit Diagram

Click here to Download PDF

Design Your Own LI-FI Dongle And Speaker Save Rs. 60.00

Design Your Own LI-FI Dongle And Speaker

by KNS Pvt Ltd
Save Rs. 60.00
Rs. 400.00
Rs. 340.00

Summary

Light Fidelity (Li-Fi) is a new paradigm in wireless communication. In this project, you can learn to design a Li-Fi dongle (transmitter) and speaker (receiver) for audio and music applications. The proposed system is a replacement for wired speakers that play audio signals received through the light.

Product Description

How It works?

1. The LED light in a room is used not just to light up the room but also to play music, thus giving benefits of both the worlds. Also, LED bulbs use 85 per cent less energy than
incandescent bulbs and last up to 20 times longer, whereas the majority of Bluetooth modules are battery powered and generally last a year or two only before they need replacement. Hence the proposed system is energyefficient over Bluetooth version.

2. You can receive Li-Fi data as long as you are in the range of the light being emitted by the LED light source. Hence, the range depends on the strength of the light being emitted.

3. Connectivity needs to be established between the Bluetooth transmitter and the receiver, whereas with Li-Fi any user can receive data and play music on his speaker by simply keeping the receiver in the range of LED light source.

4. The proposed system can be used with any audio system by just connecting the Li-Fi dongle to its audio output jack, with no pairing and connectivity requests. This overcomes the problem of connecting a Bluetooth speaker to audio systems that do not have USB port and Bluetooth support, which is otherwise a tougher task.

5. The proposed Li-Fi dongle and speaker costs lower than a Bluetooth dongle and speaker. It uses a Li-Fi dongle to transmit audio signals from a source such as mobile phone, and a Li-Fi speaker with solar cells at the receiver end to receive audio signals without wires. The proposed Li-Fi dongle is connected to the audio jack output available on mobile phones. It has an LED through which audio/music signals are transmitted as light signals. These light signals are captured by the Li-Fi speaker through the solar cell array.

Simple Automatic Water Level Controller Save Rs. 45.00

Simple Automatic Water Level Controller

by KNS Pvt Ltd
Save Rs. 45.00
Rs. 225.00
Rs. 180.00

Summary

This is a simple Automatic water controller Kit which the users can assemble in minutes and starting experimenting with it. The circuit is built around a TIMER555 and a inverting buffer CD4049. Circuit works on a 12V DC supply. Three sensors are installed with the kit to indicate lower level, higher level and VCC. At bottom of the tank VCC is placed,lower level L is placed above the VCC and higher level H is placed at the top.

Get the kit now and build yourself a reliable water controller and get amazed by how this tiny little device takes care of water level in the tank!!

Learning

Things Which you can learn:

*Application of NE555 timer.
*Application of CD4069 as inverter.
*Application and connection of relay switches to control the on/off of appliances.

Product Description

Water-level controllers are common nowadays and have become essential device in conserving water which otherwise would get wasted as the tank gets full up to its brim. The one described here is built around timer NE555 and inverter buffer CMOS IC CD4049. It uses readily-available, low-cost components, and is easy to build and install on the over-head tank (OHT) to prevent wastage of water.

Working


The circuit works off a 12V battery or 230V AC mains using a 12V adaptor. Since Vcc terminal is at the bottom of the tank, when the water level falls below sensor L, timer IC2 is triggered at pin 2 via inverters N1 and N2 and its output goes high. As a result, the output of timer IC2 goes high. Relay RL1 energises and the motor starts filling water in the tank. The motor remains ‘on’ even when the water level crosses sensor L.

As water in the tank rises to touch sensor H, timer IC2 is retriggered at pin 6 via inverters N3 and N4 and as a result, its outputgoes low. The relay de-energises and
the motor stops filling water in the tank. The motor remains ‘off’ even when the water level falls below sensor H. As water is consumed and its level falls below sensor L, the motor restarts.Thereafter, the cycle repeats.

Brand: Kits'n'spares, Marketed by: Kits'n'spares

 

Click here to Download PDF

 

Numeric Water Level Indicator with Display Save Rs. 75.00

Numeric Water Level Indicator with Display

by KNS Pvt Ltd
Save Rs. 75.00
Rs. 300.00
Rs. 225.00

Summary

Most water level indicators are equipped to indicate and detect only a single level. The Numeric Water Level Indicator implemented here can indicate up to nine such levels and displays the level no. on a seven segment display. Hence, not only is the circuit capable of cautioning a person that the water tank has been filled up to a particular level, it can also indicate that the water level has fallen below the minimum level.

This is particularly important in appliances such as the desert cooler where there is a danger of motor-burnout when the water is used up. This circuit exploits the simple fact that water is a good conductor of electricity. The placement of nine probes (having connections to the circuit) at different heights inside the water tank determines the nine different detectable levels. When the water reaches a particular height in the tank; the seven segment display shows the corresponding level no., digit 9 representing the “tank full” condition and digit 0 representing the “tank empty” condition.

Learning

Things which you can learn:


*Application of the Priority Encoder IC 74HC147
*Application of the BCD to Seven Segment Decoder IC CD4511 (for driving seven segment displays).

Product Description

The Numeric Water Level Indicator employs a simple mechanism to detect and indicate the water level in a tank or any other container. The level sensing is done by a set of nine probes which are placed at nine different levels on the tank walls (with probe9 to probe1 placed in decreasing order of height, COM probe is placed on the base of the tank). Basically, level9 represents the “tank full” condition while COM represents the “tank empty” condition.

Working

When the tank is empty, all the inputs to the priority encoder 74HC147 (IC1) remain high, as a result its output also remains high. Since these outputs are inverted and fed as inputs to the decoder driver CD4511 (IC2), all inputs to IC2 are low.

The seven segment display correspondingly shows the digit 0, indicating that the tank is empty.

When the water reaches level1 (but is below level2), pin11 (A0) of IC1 is pulled to ground and the output generated at pin9 (Y0) of IC1 also becomes low. After inversion, the bits fed to the input pins of IC2 are 0001 (DCBA). Hence, the corresponding digit displayed by the seven segment display is 1. The similar mechanism applies to the detection of all the other levels.
When the tank is finally full, all inputs to IC1 become low and all its outputs also go low. This causes all the inputs to IC2 to go high and hence the display shows a 9, thereby indicating a “tank full” condition.

 

Click here to Download PDF

 

Fastest Finger First Indicator Save Rs. 25.00
Rs. 400.00
Rs. 375.00

Fastest Finger First Indicator

Fastest Finger First Indicator

by KNS Pvt Ltd
Save Rs. 25.00
Rs. 400.00
Rs. 375.00

Summary

Build a Fastest Finger First Indicator with this simple kit interactive and use it in a quiz and game shows for indicating which player reacted or answered the fastest. The number assigned to the player is displayed by the circuit along with an alarm sound while the fastest finger buttons of the other contestant are locked.

Learning

Things Which you will Learn :

*Basics and implementation of Priority Encoder IC 7475.
*Concept and implementation of Latch
*Basics and implementation of hex inverter gates with IC 74LS04
*Concept of Binary Coded Decimal and BCD to 7 segment display IC 7447
*Concept and implementation of Frequency oscillator with NE555 IC

Product Description

The Fastest Finger First Indicator circuit determines as to which of the four contestants pressed the button first and locks out the entries from the remaining three contestants. Simultaneously, an audio alarm and the correct decimal number display of the corresponding contestant are activated.

Working


When a contestant presses his switch, the corresponding output of the latch IC 7475(IC2) changes its logic state from 1 to 0. The combinational circuitry comprising dual 4-input NAND gates of 7420 (IC3) locks out subsequent entries by producing the appropriate latch-disable signal. Priority encoder IC 74147(IC4) encodes the active-low input condition into the corresponding binary coded decimal (BCD) number output. The outputs of IC4 after inversion by inverter gates inside hex inverter 74LS04 (IC5) are coupled to BCD-to-7-segment decoder/display driver 7447(IC6). The output of IC6 drives common common-anode 7-segment LED display (DIS.1, FND507 or LT543).

The audio alarm generator comprises of the frequency oscillator NE555 (IC7), whose output drives a loudspeaker. The oscillator frequency can be varied with the help of preset VR1. Logic 0 state at one of the outputs of IC2 produces logic 1 input condition at pin 4 of IC7, thereby enabling the audio oscillator.
IC7 needs +12V DC supply for sufficient alarm level. The remaining circuit operates on regulated +5V DC supply, which is obtained using IC1 (7805). Once the organizer identifies the contestant who pressed the switch first, he disables the audio alarm and at the same time forces the digital display to ‘0’ by pressing reset push button S5.

Click To View Circuit Diagram

Click here to Download PDF

Remote Control for Home Appliances Save Rs. 50.00

Remote Control for Home Appliances

by KNS Pvt Ltd
Save Rs. 50.00
Rs. 325.00
Rs. 275.00

Summary

The Remote Control for Home Appliances can be used to switch ON and OFF any home appliance or electrical device with a single press of a TV/VCR/DVD remote control. This low-cost circuit is based on the CD4017 counter IC which receives trigger pulse from the IR sensor and switches ON the relay, through which electrical devices are switched ON. Upon receiving the 2nd pulse the device is switched OFF.

Get ready to control your home appliances from your TV Remote control and upgrade your home to a techie Palace!!

Learning

Things which you can learn:
*Application of the IR transmitter and receiver modules.
*Application of the decade counter IC CD4017.
*Use of relays to drive loads.
*Applications of Transistors as amplifiers

Product Description

The Remote Control for Home Appliances can be connected to many home appliances such as lamps, fans, radios, etc to make the appliance switch ON/OFF from a TV, VCR or DVD remote control. This circuit can be operated from upto 10 meters.

Working


The 38kHz infrared (IR) rays generated by the remote control are received by IR receiver module TSOP1738 of the circuit. The output signal (from pin3) is amplified by transistor T1 (BC558). This amplified signal is fed to the clock pin (pin no.14) of decade counter IC CD4017 (IC1), pin 3 of which is connected to a red LED (LED1). This LED glows to indicate that the appliance is OFF. The output (pin no.2) of IC1 is connected to a green LED (LED2) and is used to indicate the ON state of the appliance. Transistor BC548 (T2) is connected to pin 2 of IC1 and drives the relay RL1.

The appliance to be controlled is connected between the pole of the relay and neutral terminal of mains. It gets connected to live terminal of AC mains via normally opened (N/O) contact when the relay energizes.

Click To View Circuit Diagram

Click here to Download PDF

CHIP-TALK Hobby Projects Book

CHIP-TALK Hobby Projects Book

by KNS Pvt Ltd
Rs. 80.00
Save Rs.100! Get the digital edition or eBook version to save on shipping. 

Summary

Electronics Field is very vast and for those who want to enter this segment in a systematic step by step method, the CHIP TALK offers the best platform where it provides basics of all the necessary concepts required to build projects and moreover it comes with a 40 tested projects circuits to boost your confidence in building and enjoying the projects.
CHIP-TALK Hobby Projects package includes components and breadboard for prototyping 40 fully tested projects. The book contains the fundamentals of electronics and 40 tested circuits and their descriptions.

Learning

Things which you can learn:

*Applications of different ICs like CD4011, CD4001, NE555, op amp etc.
*Application LED, IR LED, Variable resistor and capacitor, inductor.
*Application of L14F1.
*Application of ultrasonic transmitter and receiver.
*Use of breadboard.
*Application of transistor as amplifier and switch.
*Use of different switches like DPDT, SPDT, SPST.
*Use of relay.

Product Description

An Awesome platform for those who are looking to build and learn electronics project with easy access to all the circuits and necessary informations supporting the project.

CHIP-TALK Hobby Projects package includes components and breadboard for prototyping 40 fully tested projects. The book contains the fundamentals of electronics and 40 tested circuits and their descriptions. Below is the list of projects:

1.Circuit Symbols & conventions
2.Basic Tools and Test Equipment
Hand tools
Multimeter
Logic Probe
Trimming tool set.
3.Soldering/de-soldering equipment
SOLDERING TIPS
4.Safety precaution for preventing electric shock
5.Ohm’s law
6.Fixed and Variable Resistors
Resistor Colour code and conventions
Naming Convention.
The E12 Range
The E24 Range
Simplifying The Color Code
Resistor wattage
7.Capacitors and capacitive reactance.
Colour coding and marking schemes for fixed capacitors
IEC letter and digit code for r & c values
Conversion table for capacitance values
8.Inductors (coils) and inductive reactance
9.Circuit assembly
Breadboard.
Stripboard
Printed Circuit Board
10.Illustrations of some commonly used components
Tactile switch
Loudspeaker
Piezo Buzzer
Diodes
Light Emitting Diode (LED)
7-Segment LED display
DIL/DIP switch
SIL/SIP RNW
11.Stabilized Power-supply
12. Versatile TTL/CMOS Logic and Clock Probe

Part II
Section 1

12.UM66TXXX Melody generator-based projects
General Description
XXX suffix


13.Project 1. A simple melody player
14.Project 2. Melody player using speaker
Modifications UM66TXXS (single shot)
15.Project 3. Musical call bell
16.Project 4. Musical hold-on for Telephone
17.Project 5. Timer with Musical Alarm
18.Project 6.Intercom with Musical Ringtone
19.Project 7. Soft Musical Telephone Ringer
20.Project 8. Touch-sensitive Musical Bell with delay
21.Project 9. Musical Continuity Tester

Section 2

22. TTL and CMOS logic based circuits
Noise immunity
Fan-out
Propagation delay
Power requirements
Comparison. (CMOS VS TTL)
23. CD4011 quad 2-input NAND gate to realize:
Inverter. Or Not gate
AND gate
OR gate
NOR gate
XOR gate
24. NAND gate(s) based circuits
Project 10. A set-reset (Bi-stable) flip flop
Project 11. Touch Sensitive Alarm
Project 12. On/off Ringer
Project 13. Toilet Busy Indicator
Project 14. Electronic Direction Pointer
Project 15. Simple Soil Moisture level Controller
Project 16. Touch Sensitive Single-chip Flasher-cum-beeper
Project 17. Automatic Pump Controller
Project 18. Generating Three Tones Using a Single digital IC

Section 3

25. Timers and Counters
555 Timer and 556 dual Timer
Monostable mode (555 timers)
Astable mode (555 timers)
CD4017 counter
CD4026B and CD4033B Counters
26. Timer and counter based circuits
Project 19. Divide-by-N counter using CD4033
Project 19A. Divide-by-2 through 6 and 8 (using CD4033)


Project 19B. Divide-by-7 counter (using CD4033)
Project 19C. Divide-by-9 counter (using CD4033)
Project 20. Divide-By-N Counter Realization
Using 555, CD4033 And CD4017
Project 21. Telephone Call Counter
Project 22. Mains Interruption Counter with Indicator
Project 23. Timer For Students
Project 24. DICE with 7-segment display

Section 4

Project 25. Simple smoke Alarm
Project 26. Concealed AC mains line detector.
Project 27. Speed Control Of Dc Motor Using Pulse-Width Modulation.
Project 28. IR to RF Converter.
Project 29. Contactless Telephone Ringer.
Project 30. Preamplifier (signal booster) for FM Band.
Project 31. Condenser mike Amplifier.
Project 32. Cordless F. M Mike.
Project 33. Laser Controlled On/Off Switch
Project 34. Phone broadcaster
Project 35. Anti-theft Alarm.
Project 36. Touch Dimmer.
Project 37. Doorbell using UM3561
Project 38. Poor man’s Miniature hearing Aid.
Project 39. Line-powered two-tone ringer.
Project 40. Ding-Dong Bell.
Project 41. Rechargeable White LED Torch

Speed Checker For Highways

Speed Checker For Highways

by KNS Pvt Ltd
Rs. 650.00

Summary

While driving on highways, motorists tend to exceed the maximum permissible speed limit set by the traffic department. The speed checker implemented here is a low cost solution which will allow the traffic policemen to monitor speeds. The Speed Checker for Highways displays a digital reading corresponding to the vehicle’s speed and also sounds an alarm if the vehicle exceeds the permissible speed for the highway.


The speed-sensing is done by the means of two laser transmitter-LDR sensor pairs. These are installed on the highway 100 meters apart, with the transmitter and the LDR sensor of each pair on the opposite sides of the road. The system displays the time taken by the vehicle to cross this 100m distance from one pair to the other with a resolution of 0.01 second. The speed of the vehicle can be calculated from the simple speed-time-distance equation.

Learning

*Application of the NE555 timer in the monostable and astable mode.

*Application of the decade counter/7-segment decoder IC CD4026.

Product Description

The Speed Checker Kit for Highways is a simple kit based on 555 Timer IC, NAND gate inverter, Decade counter and 7 segment display to calculate the speed of vehicles , plying on the road.


Working


The Speed Checker for Highways implemented here assumes that the maximum permissible speed for highways is either 40Kmph or 60Kmph as per the traffic rule. For 40kmph limit the time period is set for 9 seconds using preset VR1, while for 60kmph limit the time period is set for 6 seconds using preset VR2. Slide switch S1 is used to select the time period as per the speed limit i.e. either 40Kmph or 60Kmph. The junction of LDR1 and resistor R1 is coupled to pin2 of IC1. Normally, light from the laser keeps falling on the LDR sensor continuously and thus the LDR offers a low resistance and pin2 of IC1 is high.


Whenever light falling on the LDR is interrupted by any vehicle, the LDR resistance goes high and hence pin 2 of IC1 goes low to trigger the monostable. As a result, output pin3 goes high for the preset period, either 9 or 6 seconds, and LED1 glows to indicate it. Reset pin 4 is controlled by the output of NAND gate N3 at power-on or whenever reset switch S2 is pushed. For IC2, the monostable is triggered in the same way as IC1 when the vehicle intersects the laser beam incident on LDR2 to generate a small pulse for stopping the count and for use in the speed detection. LED2 glows for the duration for which pin 3 of IC2 is high.


The outputs of IC1 and IC2 are fed to input pins 2 and 1 of NAND gate N1, respectively. When the outputs of IC1 and IC2 go high simultaneously i.e. the vehicle has crossed the preset speed limit, output pin 3 of gate N1 goes low to trigger mono-stable timer IC3. The output of IC3 is used for driving piezoelectric buzzer PZ1, which alerts the operator of speed-limit violation.


Resistor R9 and capacitor C5 decide the time period for which the piezoelectric buzzer sounds. The output of IC1 triggers the bistable (IC4) through gate N2 at the leading edge of the count-start pulse. When pin2 of IC4 goes low, the high output at its pin 3 enables astable clock generator IC5. Since the count-stop pulse output of IC2 is connected to pin6 of IC4 via diode D1, it resets clock generator IC5. IC5 can also be reset via diode D2 at power-on as well as when reset switch S2 is pressed.

Click To View Circuit Diagram

 

 

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Moisture Monitor For Plants Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Moisture Monitor For Plants

Moisture Monitor For Plants

by KNS Pvt Ltd
Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Summary

The circuit is based on CD4060 14 Stage binary ripple counter which provides a frequency at pin 7 of the CD4060 which is decreased at pin 4 and gives a train of pulses for the transistor to switch the buzzer

Learning

CD4060 is a ripple counter IC which is widely used in digital electronics and this circuit teaches a concept which can be used to innovate new circuits based on CD4060

Product Description

Over-watering and under watering both are harmful to plants. Roots need air as well as water. If the soil is constantly saturated, air cannot reach the roots and they suffocate. Also, excess water weakens the plant and makes it susceptible to various diseases, particularly fungal attacks. Underwatering, on the other hand, is equally harmful. Plants not receiving enough water drop from the top down and leaf edges turn brown. Moisture monitor provides a solution to the above problem by monitoring the moisture level of the soil and producing an audio visual alert when the moisture goes below a preset level, indicating that the plant needs to be watered.

Click To View Circuit Diagram

Click here to Download PDF

Basic Electronic Kit + Soldering Kit For Starters

by KNS Pvt Ltd
Save Rs. 101.00
Rs. 600.00
Rs. 499.00
Are you looking for a project kit that you can solder? Check these out.

Summary

A simple electronic kit which is packed with all the important component to help you learn practically. It comes with components like NE555, transistors, resistors, breadboard, LEDs, general purpose PCB and a soldering kit.

Learning from the project

1. Learn about the architecture of breadboard and project implementation in breadboard
2. Learn about transistors as amplifiers, switches and also the types like NPN and PNP.
3. Learn about light emitting diode, its minimum bias current and the concept of forward and reverse bias modes.
4. Learn about NE555 timer IC as a pulse generator, oscillator, and a timer and its operation under different modes
i. Bistable
ii. Monostable
iii. Astable
5. Learn how to solder, different types of soldering, the importance of Dry Solder, the Minimum heat required to melt the solder.
6. Learn how to effectively use de-solder pump in removing the solder from the PCB

Product description

Want to get involved in electronics, but confused where to start. Do not worry, this basic electronic kit provides a perfect platform for people looking to learn practically by doing things.

This kit comes with accessories which are a must for beginners to gets their hands dirty. So stop thinking and buy this kit to get started on your dream to build electronic projects.

Kit includes

1.Bread Board: An extremely important tool for beginners to try different projects without the need of soldering
2.GPCB: General Printed Circuit Board: This is basically a General PCB where you can build your projects by soldering electronic components in it.
3.Resistors- A set of commonly used resistors which are essential in building simple electronic projects.
4.LED RGB - Light emitting diode, essential for making your projects interactive. Comes in Red, Blue and Green color.
5.Transistors - This is a very important component when it comes to amplifying the current in electronic circuits and also to acts as a switch.
6.NE 555 IC: used in a variety of timer, pulse generation, and oscillator applications.
7.Bread Board Wire - Single strand wire for breadboard use.
8.Soldering Iron - Important tool for soldering the components to PCB
9.De-soldering pump- Used to remove solder from PCB
10. Flux - For cleaning the Soldering rod and protect it from oxidization
11.Lead - The main solder which is melted to make electrical contact.

Burglar Alarm Save Rs. 25.00
Rs. 150.00
Rs. 125.00

Burglar Alarm

Burglar Alarm

by KNS Pvt Ltd
Save Rs. 25.00
Rs. 150.00
Rs. 125.00

Summary

The burglar alarm implemented here is a simple circuit that automatically sounds an alarm whenever an intrusion is detected. The system is implemented by installing a simple sensing loop, which is basically a thin copper wire. This way, the loop is both invisible and brittle enough to break easily and initiate the alarm mechanism.

At the time of an intrusion, the loop breaks and this causes the loudspeaker to generate a continuous and loud alarm sound. Once the loop is broken, the alarm can only be silenced by either turning OFF the power supply or by replacing the broken wire by a new continuous loop. Number of ICs used: None

Learning

Things which you can learn:

*Operation of transistors (both NPN and PNP type) in different modes, especially in conduction and cut-off mode.
*Two stage amplifier with feedback.

Product Description

The Burglar Alarm circuit employs a simple mechanism to sound an alarm when an intrusion is detected. If the loop is broken then an intrusion is detected and the alarm is sounded.

Working

It consists of an oscillator section which is merely a two-stage amplifier with feedback. This amplifier is implemented with the help of two transistors (T1 is an NPN transistor-BC548 while T2 is a PNP transistor-SK100) connected in a feedback arrangement to generate oscillations. Transistor T1 is responsible for generating oscillations while transistor T2 (connected to the base of T1) amplifies these oscillations in order to drive the loudspeaker for sounding the alarm.

Consider the following cases:

1. Secure Premises: The connection of the two transistors is such that the base of T1 is normally shorted to the ground and that it remains in the cut-off mode when the sensing loop is intact. Due to the absence of the base current in T1 in this mode, there are no oscillations and hence, the loudspeaker does not generate the alarm sound. This indicates that no intrusion has taken place.

2. Intrusion: When the loop is broken by an intruder or a burglar, the base of transistor T1 becomes open and oscillations are generated at its collector. As the base of T2 is connected to the collector of T1, the oscillations are amplified by it and further fed back to its emitter (via the path along capacitor C1 and resistors R1, R2). The loudspeaker obtains this amplified signal from the collector of transistor T2 and converts it into audible alarm sound. This indicates the occurrence of an intrusion/break-in.

As both the transistors are silicon type, the current drawn by the circuit is very low even in the alert mode.

 

Click here to Download PDF

 

Smoke Alarm Save Rs. 25.00
Rs. 200.00
Rs. 175.00

Smoke Alarm

Smoke Alarm

by KNS Pvt Ltd
Save Rs. 25.00
Rs. 200.00
Rs. 175.00

Summary

Most smoke detecting circuits available commercially, make use of expensive smoke sensors which require complicated interfacing circuitry around them. However, the Smoke Alarm implemented here is capable of detecting smoke consistently and employs a simple phototransistor optical interrupter switch as the smoke sensor. This smoke-detecting circuit utilizes the simple fact that in case smoke is present, the optical signal transmitted from the infrared emitting diode to the photo-transistor (both part of the photo interrupter module) will be interrupted. Once such a situation is encountered, an alarm sound is generated by the loudspeaker till the time smoke clears. Number of ICs used: 1.

Learning

Things Which you can learn:
*Application of the phototransistor optical interrupter switch H21A1
*Implementation of the astable mode of the NE555 timer IC.

Product Description

The smoke alarm circuit employs a simple mechanism to detect smoke in the vicinity and sound an alarm. The sensing is done by the photo-transistor optical interrupter switch while the alarm is sounded by the NE555 timer IC, the output of the former acts as the input of the latter.

Working

In the absence of any smoke, the gap of the photo-transistor interrupter housing is clear and the infrared light from the diode falls directly onto the photo-transistor. This keeps the photo-transistor of the optical interrupter module in saturation. Owing to this, the reset pin (active LOW) of the NE555 IC is pulled to ground and it continuously resets the NE555 timer IC. No output is generated at pin3 and hence the loudspeaker does not sound an alarm.

In case of smoke, the gap between the diode and the photo-transistor gets clouded with smoke and the optical signal is interrupted. (The threshold value of the least detectable smoke density is decided by the variable resistor VR1). This interruption in the optical signal causes the base voltage of photo-transistor to fall and cut-off. As a result, the collector terminal of the photo-transistor as well as the reset pin (pin no.4) of the NE555 IC is held high via resistor R2. Hence, oscillations are generated at the output pin (pin no.3) of the NE555, the frequency of which is decided by the value of R3, R4 and C1. This electrical signal (oscillations) is input to the loudspeaker through the capacitor C3 and is further converted into a loud and continuous alarm sound.

Click To View Circuit Diagram

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Automatic Night Lamp Dimmer with Morning Alarm Save Rs. 75.00

Automatic Night Lamp Dimmer with Morning Alarm

by KNS Pvt Ltd
Save Rs. 75.00
Rs. 300.00
Rs. 225.00

This automatic night lamp serves a dual purpose, depending on the intensity of light rays detected. The circuit is capable of automatically switching ‘ON’ a white LED on detecting darkness, to act as a night lamp. Conversely, it can also sense daylight and play a melodious tune as a morning alarm. The circuit operates on AC supply and the circuit also provides for battery backup in case of power failure.

No. of ICs used: 3

Learning from this project

  • Application of NE555 timer IC in monostable mode.
  • Concepts related to the working of light dependent resistors.
  • Implementation of bridge rectifier circuit for AC to DC conversions.
  • Application of the music generator IC UM66.

Product Description

This project builds an automatic lamp with night dimmer and morning alarm. It can set the ambient light of your room and also wake you up when the sun rises.

Working

The automatic night lamp dimmer with morning alarm is powered by a standard 0-9V transformer. Diodes (D1-D4) rectify the AC voltage and the resulting DC voltage is smoothed by a capacitor (C1). Voltage regulator IC (7806) provides regulated 6V DC supply to the circuit while battery backup is also provided to power the circuit when mains fails. When mains supply is available, a 9V rechargeable battery charges via a diode (D5) and a resistor (R1) with a reasonably constant current. In the event of a power failure, the battery automatically takes up the load without delay.

The circuit uses light dependent resistors (or LDR) for sensing ambient light conditions. Typically, an LDR offers high resistance in darkness, which reduces to a minimum when bright light is incident on it. In this automatic night lamp dimmer circuit, one LDR (LDR1) detects darkness while another LDR (LDR2) detects light in the morning.

The circuit is designed around the single timer IC NE555 (IC2), which is configured to work in the monostable mode in the circuit. IC2 is activated by a low pulse applied to its trigger input (pin 2). Once triggered, the output pin (pin 3) of IC2 goes high and remains in that position until IC2 is triggered again by the input at pin 2. When LDR1 is illuminated by the ambient light, its resistance falls to a minimum and pin 2 (trigger input) of IC2 remains at a positive potential. This causes the output (pin 3) of IC2 to go low and hence, the white LED remains off.

In absolute darkness, the LDR has a resistance in excess of 280-kilo ohms. So, when the resistance of LDR1 increases, a short pulse is applied to trigger input (pin2) of IC2 via a resistor (R2).

This triggers the monostable mode of operation and the output pin of the NE555 (IC2) goes high, causing the white LED to glow. A low-value capacitor (C2) maintains the monostable for continuous operation, eliminating the timer effect. By increasing the value of C2, the ‘ON’ time of the white LED can be adjusted. LDR2 and associated components generate the morning alarm at dawn. LDR2 detects the ambient light in the room at sunrise and its resistance gradually falls. This makes a transistor (T1) to start conducting. When T1 conducts, a melody-generator IC UM66 (IC3) gets supply voltage from the emitter of T1 and it starts producing the melody. A single-transistor amplifier (T2) amplifies the musical tone generated by IC3.

Click To View Circuit Diagram

Click here to Download PDF

Door Guard Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Door Guard

Door Guard

by KNS Pvt Ltd
Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Thieves often target locked houses. This door guard circuit detects any vibration in its vicinity when somebody tries to break open the door. A simple circuit to protect all your valuable things.

Learning from this project

Things which you can learn:

  • Application of UM3561 IC.
  • Working of the transistor as an amplifier.
  • Working of MOSFET BS170.
  • Application of piezoelectric sensor.

Product Description

This is a simple door guard circuit which is based on piezo electric sensor to detect changes in the vibration caused due to the opening of doors.

Project working

The heart of the circuit is the piezo transducer (PZ1), which is the sensor element. If anyone attempts to open the door, the piezo element vibrates and the developed voltage drives transistors T1 and T2 into conduction. Then the alarm sounds for 20 seconds, which is taken care of by MOSFET T3 along with capacitor C1 and resistor R4 wired as a monostable timer.

 

Click here to Download PDF

Water level Indicator

Water level Indicator

by KNS Pvt Ltd
Rs. 100.00

Summary

The purpose of the water level indicator is to caution a person that a water tank has been filled up to a particular level. This circuit exploits the simple fact that water is a good conductor of electricity. The system is capable of indicating the water level in two ways- visual (by the means of an LED) and audible (by the means of a sound generated by a piezoelectric buzzer).

The placement of two probes (with connections from the circuit) inside the water tank determines the minimum detectable level (MDL). When the water reaches this height in the tank (or any other fluid container), the buzzer is activated and the LED is turned on. Number of ICs used: None.

Product Description

The water level indicator employs a simple mechanism to detect and indicate the water level in a tank or any other container. The level sensing is done by a pair of probes, the resistance between which depends upon the water level in the tank. These probes can be placed in two ways on the walls of the tank or container.

Working

1. Both the probes can be placed at different points on the wall lying at the same level/height from the bottom. This height determines the minimum detectable water level, or

2. The probes can be placed at different points lying at two different heights from the tank bottom. In this case, the probe which is placed higher than the other determines the minimum detectable water level.

When the water-level is below the minimum detectable level (MDL), there is infinite impedance between the two probes. Hence, transistor T2 remains in the cut-off mode and does not conduct. However, when water-level reaches MDL or is above it, the connection between the probes gets completed (through the conducting medium o water) and the base voltage of T2 increases.

This causes the base-emitter junction of T2 to get forward biased and the piezoelectric buzzer is turned on to generate an alarm sound. The path from the emitter of T2 through resistance R3 is responsible for forward biasing the base of transistor T1. This switches T1 from cut-off to conduction mode, thereby driving the red LED to glow. Hence at each instance when water reaches the MDL, both the buzzer and LED indicate this simultaneously.

 

Click here to Download PDF

 

Sunset Lamp
Rs. 100.00

Sunset Lamp

Sunset Lamp

by KNS Pvt Ltd
Rs. 100.00

Summary

This kit is based on the principle of Light dependent resistor . Thus when the sun sets the ambient light in the environment decreases and thus the light glows up.

Learning

Things which you will learn:

*Application of NE555 in bi stable mode.
*Concepts related to the working of Light Dependent Resistors.
*Application of TRIAC BT136.
*Application of Zener Diode.

Product Description

Build this automatic sunset light , which will light up when its dusk and will help in conserving electricity .

Working

The circuit uses popular timer IC NE555 as a Schmitt trigger to give the bistable action. The set and reset functions of the comparators within the NE555 are used to give the instantaneous action. The upper threshold comparator of IC1 trips at 2/3Vcc, while the lower trigger comparator trips at 1/3Vcc.The inputs of both the threshold and the trigger of NE555 are tied together and connected to the voltage divider formed by LDR1 and
VR1. The voltage across LDR1 depends on the light intensity.

In daylight, LDR1 has low resistance and the input voltage to the threshold comparator goes above 2/3Vcc and its output becomes zero, and the lamp remains off.
At sunset, the resistance of LDR1 increases, and the voltage at the input of the threshold comparator decreases below 2/3Vcc and that of the trigger comparator goes below 1/3Vcc. As a result, the outputs of threshold and trigger comparators go high. Thus it completes the power supply to the lamp through triac1. LED1 glows to indicate the high output state.

 

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Cordless FM MIC Save Rs. 50.00
Rs. 200.00
Rs. 150.00

Cordless FM MIC

Cordless FM MIC

by KNS Pvt Ltd
Save Rs. 50.00
Rs. 200.00
Rs. 150.00

Summary

The Cordless FM Mic can be used as an FM transmitter. The frequency transmitted by the circuit is FM modulated and hence the voice at condenser microphone can be listened to through a standard FM receiver.

Learning

Things which you can learn:

*Concepts related to FM modulation and transmission.
*Application of NPN transistors as signal amplifiers.
*Application of the condenser mic as an input device.

Product Description

Build a simple circuit which can be used as a one-way walkie talkie. Use this kit to transmit your voice over FM and receive the sound in a standard FM receiver.

Working

The circuit of the Cordless FM Mic consists of a high-frequency air core coil (L1) with six closely wound turns of 25 SWG enameled copper wire on 4 mm diameter air former. The range of this transmitter can be enhanced by connecting a 30-60cm long wire as an antenna and changing the value of the 0.0015 micro Farad capacitor to up to 33 Pico Farad.

The range and transmitted frequency can be changed by increasing or decreasing the length of wire which is connected to a collector of NPN transistor 2N2369 (T2)via a capacitor. NPN transistor BC548 (T1) works as a condenser mic amplifier and T2 works as an FM oscillator and modulator by the help of other passive components. The main advantage of this transmitter is that it works off a 3V battery which can be easily obtained from two AA size pencil batteries.

Click To View Circuit Diagram

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