Products

"Grab!" Gift Card for Techies

"Grab!" Gift Card for Techies

by DANV
Rs. 50.00

Give the gift of choice!

Shopping for someone else but not sure what to give them? Give them the gift of choice with a "Grab!" gift card.

Your recipient can use this gift card to buy their favourite product from the Grab! store.

Gift cards are delivered by email and contain instructions to redeem them at checkout. Our gift cards have no additional processing fees.

SPECIAL OFFER RUNNING NOW: For any gift card you buy, we will gift you with an additional gift card worth 5%!

6 in 1 Gift Box Save Rs. 101.00
Rs. 700.00
Rs. 599.00

6 in 1 Gift Box

6 in 1 Gift Box

by KNS Pvt Ltd
Save Rs. 101.00
Rs. 700.00
Rs. 599.00

The Gift box contains 5 electronic project kits and a soldering kit to make them. Gift Box has one each of the following kits;

  • Musical Touch Bell
  • Musical Door Bell
  • Water Level Indicator
  • Burglar Alarm
  • Magic Eye
  • Soldering Kit

Learning from the kit

Things you can learn,

  • Application of the melody generator IC BT66 (or UM66).
  • Application of PNP and NPN type transistors for switching purposes.
  • Application and implementation of the NE555 timer IC in the astable mode.
  • Principle involving the use and function of LDRs (Light Dependent Resistors) and their application.
  • Hands on experience of soldering different components.

Product Description

The 6 in 1 gift box is a complete kit for those keen on developing quality electronic projects. It contains 5 projects which test your skills at a different level. It also contains a soldering kit required to complete this kit. This box opens up a great opportunity for learning.

Musical Touch Bell: The Musical Touch Bell implemented here can be operated by just bridging the gap between two touch plates by one’s fingertips and requires minimal power consumption. The circuit generates a pleasant musical tone through a melody generator IC, as long as the touch plates are in contact.

Musical Door Bell: Most conventional doorbells available in the market generate alarm for a specific time duration which cannot be reprogrammed or controlled. This can be annoying when a person has answered the door immediately. The musical doorbell (with memory) implemented here is a simple doorbell whose ringing duration can be varied easily. The circuit generates a pleasant musical tone for a preset time duration after the toggle switch is pressed.

Water Level Indicator: The purpose of a water level indicator is to caution when 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).

Burglar Alarm: The burglar alarm implemented here is a simple circuit that sounds an alarm on detecting intrusion. 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 causing the loudspeaker to generate a continuous and loud alarm sound.

Magic Eye: It can be used for a variety of applications like a burglar alarm, smoke detector or an automatic guest indicator. All these applications make use of the Light Dependent Resistor (LDR) which is installed and implemented differently in each case.

Soldering Kit-Contains basic tools for soldering.

7-Segment Module Save Rs. 75.00
Rs. 200.00
Rs. 125.00

7-Segment Module

7-Segment Module

by KNS Pvt Ltd
Save Rs. 75.00
Rs. 200.00
Rs. 125.00

This module includes inbuilt power LED with separate data and control pins.

Learning from the module

Build different projects using 7-Segment modules.

Product Description

Seven segments LED displays are very popular means of displaying numerical information and finds application in front panel display boards of microwave ovens, washers and dryers, digital clocks, frequency counters, and many other gadgets. Compared to LCD displays, seven segment LED displays are brighter and provide farther viewing distance and wider viewing angles.

8051 Pocket Programmer-USB TNP - 1 Save Rs. 51.00

8051 Pocket Programmer-USB TNP - 1

by KNS Pvt Ltd
Save Rs. 51.00
Rs. 650.00
Rs. 599.00

The 8051 microcontroller programming tool is a powerful yet low-cost tool for programming 8051 microcontroller.

Supported ICs: AT89S51 AT89S52 AT89S55 AT89S2051 NOTE: This programmer does NOT support "C" series of Atmel as the series is obsolete. But you can burn your program written for "C" series, without any changes to "S" series of Atmel controllers.

Learning

Learning and practicing 8051 microcontroller commands.

Product Description

It is a programmer for the 8051 microcontroller family and a very comfortable tool for any developer. It is a powerful yet low-cost tool for programming 8051 microcontrollers . With USB communication and easy GUI, microcontroller programming has been made simple than ever before. It supports various microcontrollers focusing on the Atmel series.

Features:
*USB compatible

Powered:
*On board ZIF Socket
*On board ICSP pin
*On board Test LEDs

Anti-Bag Snatching Alarm Save Rs. 100.00
Rs. 400.00
Rs. 300.00

Anti-Bag Snatching Alarm

Anti-Bag Snatching Alarm

by KNS Pvt Ltd
Save Rs. 100.00
Rs. 400.00
Rs. 300.00

This anti bag snatching alarm builds a circuit that is locked in a plug and socket arrangement in standby mode. The kit can be kept in a bag or suitcase, and simulates a police horn if someone attempts to snatch the bag. Thus, while traveling, this kit enables people to carry cash or valuables without fear. The alarm can be turned off only by the authorized person by using a hidden key.

Number of ICs used: 3

Learning from the project

*Application of the operational amplifier IC CA3140 as a comparator.
*Application of the NE555 timer IC in monostable mode.
*Use of the music generator IC UM3561.
*Use of transistors as signal amplifiers.

Product description

Build yourself an awesome anti bag snatching alarm and protect your luggage and travel care-free.

Circuit working

The circuit of the anti bag snatching alarm is designed around the operational amplifier CA3140 (IC1) configured as a comparator. The non-inverting input (pin3) of IC1 is kept at half the supply voltage (around 4.5V) by a potential divider resistor network. The inverting input (pin 2) of IC1 is kept low through the shorted plug at the socket. As a result, the voltage at the non-inverting input is higher than the inverting input and the output of IC1 is high.

The output from pin 6 of IC1 is fed to trigger pin 2 of IC NE555 (IC2) via a coupling capacitor. IC2 is configured in monostable mode. The trigger pin is held high by a resistor of 10 kilo-ohms. Normally, the output of IC2 remains low and the alarm is off. A resistor and a capacitor are connected to the reset pin of IC2 to prevent false triggering.

When there is a bag-snatching attempt, the plug connected to the circuit detaches. At this moment, the voltage at the inverting input of IC1 exceeds the voltage at the non-inverting input and subsequently, the output goes low. This sends a low pulse to trigger pin 2 of IC2 to make its output high. Consequently, the alarm circuit built around IC UM3561 (IC3) gets the supply voltage at pin 5.

Its output is fed to the base of single-stage transistor amplifier BD139 (T1) that amplifies the generated alarm signal. A loudspeaker is connected to the collector of T1 to produce the alarm. The alarm can be put off if the plug is inserted into the socket again.

Click To View Circuit Diagram

Click here to Download PDF

Anti-Theft Alarm for Vehicles Save Rs. 100.00
Rs. 400.00
Rs. 300.00

Anti-Theft Alarm for Vehicles

Anti-Theft Alarm for Vehicles

by KNS Pvt Ltd
Save Rs. 100.00
Rs. 400.00
Rs. 300.00

This anti theft alarm for vehicles is a security system for vehicles that generates a loud and continuous alarm in case any unauthorized person tries to gain access to your vehicle. As soon as a thief tries to start the ignition, the vehicle alarm is activated, leaving no option other than to flee as the alarm can be reset and turned OFF by the owner alone. Build this kit to prevent theft of your vehicle.

Learning from this project

  • Application of music generator IC UM3561
  • Application of NPN transistors for switching purposes
  • Application of SCRs for sensing and switching
  • Application of capacitors for temporary storage

Product description

The anti theft alarm for vehicles simulates a police siren whenever someone attempts to commit theft of your vehicle. The alarm sounds continuously for a few seconds even when the intruder switches off the ignition key.

Circuit working

The circuit consists of an SCR based trigger circuit and an audio alarm circuit. When the ignition key of the vehicle is switched off, the base voltage of the NPN transistor SL100 (T1) is low and it remains off. When the ignition key is switched on for starting the vehicle, a positive voltage is applied to the base of transistor T1 through diode D1, toggle switch (S2) and a resistor (R1) which slowly charges the 100 microfarad capacitor (C1). As a result, the base voltage of T1 rises.

As soon as the biasing voltage crosses cut-in voltage, T1 turns on and the SCR fires, giving 12V DC voltage to the alarm circuit. The alarm circuit is built around the music generator UM3561 (IC1) which has an inbuilt oscillator. The output from IC1 is fed to a transistor amplifier built around transistors BC548 (T2) and SL100 (T3). The circuit gives sufficient time delay to switch ON the alarm and leave the vehicle. The alarm once triggered, sounds until the toggle switch S1 is pressed to switch off the power supply.

A 220 microfarad capacitor (C2) is provided to sound the alarm even when the intruder switches off the ignition key. When the ignition key is switched off immediately, C2 discharges through a resistor R4 and keeps the alarm activated for half a minute. Reset switch (S3) is used to reset the alarm if needed.

Click To View Circuit Diagram

Click here to Download PDF

Arduino Starter Kit Save Rs. 201.00
Rs. 2,000.00
Rs. 1,799.00

Arduino Starter Kit

Automatic Low Power Emergency Light Save Rs. 250.00

Automatic Low Power Emergency Light

by KNS Pvt Ltd
Save Rs. 250.00
Rs. 1,000.00
Rs. 750.00

The automatic low power emergency light is a white LED based emergency light that offers the following advantages:

  1. It is extremely bright due to the use of white LEDs.
  2. The light turns ON automatically when mains supply fails and turns OFF when mains power resumes.
  3. It has its own battery charger. When the battery is fully charged, charging stops automatically.

No. of ICs used: 1

Learning from this project

  • Application of the adjustable voltage regulator IC LM317.
  • Application of Zener diodes for voltage regulation.
  • Application of diodes in the bridge arrangement for rectification.
  • Application of NPN and PNP transistors.

Product Description

Build yourself a cool automatic low power emergency light which can be used during a power failure. An added bonus is that it charges automatically.

Circuit operation

This automatic low power emergency light comprises of two sections: charger power supply and LED driver.

The charger power supply section is built around the 3-terminal adjustable voltage regulator IC LM317 (IC1), while the LED driver section is built around the transistor BD140 (T2).
In the charger power supply section, input AC mains is stepped down by transformer X1 to deliver 9V, 500 mA to the bridge rectifier comprising of four diodes (D1 through D4). A filter capacitor (C1) eliminates ripples.

Unregulated DC voltage is fed to input pin 3 of IC1 and provides charging current through a diode (D5) and a limiting resistor (R16). By adjusting the preset (VR1), the output voltage can be adjusted to deliver the required charging current. When the battery gets charged to 6.8V, zener diode (ZD1) conducts and charging current from regulator IC1 finds a path through the NPN transistor T1 (BC548) to ground and it stops charging the battery.

The LED driver section uses a total of twelve 10mm white LEDs. All the LEDs are connected in parallel with a 100-ohm resistor in series with each. The common-anode junction of all the twelve LEDs is connected to the collector of the PNP transistor BD140 (T2) and the emitter of this transistor is directly connected to the positive terminal of the 6V battery. The unregulated DC voltage, produced at the cathode junction of diodes D1 and D3, is fed to the base of transistor T2 through a 1-kilo-ohm resistor.

When mains power is available, the base of transistor T2 remains high and T2 does not conduct. Thus LEDs are off. On the other hand, when mains fails, the base of transistor T2 becomes low and it conducts. This makes all the LEDs (LED1 through LED12) glow. The mains power supply, when available, charges the battery and keeps the LEDs off as transistor T2 remains cut-off. During mains failure, the charging section stops working and the battery supply makes the LEDs glow.

Click To View Circuit Diagram

Click here to Download PDF

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

Automatic Room Light Controller with Visitor Counter Save Rs. 301.00

Automatic Room Light Controller with Visitor Counter

by KNS Pvt Ltd
Save Rs. 301.00
Rs. 3,300.00
Rs. 2,999.00

This automatic room light controller project with visitor counter is a reliable circuit based on the AT89S52 microcontroller. It takes over the task of controlling room lights as well us counting the number of people in a room accurately. When somebody enters a room, the counter is incremented by one and the light in the room is switched 'ON' and when any one leaves the room, the counter is decremented by one. Light is only switched 'OFF' when all the people in the room go out.

The total number of people inside the room is also displayed on the seven segment display by the microcontroller. It receives signals from the sensors, and this signal is operated under the control of software stored in ROM. Microcontroller AT89S52 continuously monitors the Infrared receivers. When any object passes through IR receivers, the IR rays falling on the receivers are obstructed, this obstruction is sensed by the microcontroller

Brand: HBeonLabs, Product assembled by: HBeonLabs

 

 

Click here to Download PDF

 

Automatic School Bell Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Automatic School Bell

Automatic School Bell

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

This automatic school bell finds use in educational institutes, factories and organizations where accurate time keeping and bell timings are necessary. This circuit automatically sounds an alarm 8 times, at intervals of 45 minutes each. After 4 intervals, a 30-minute lunch break or recess is also timed/belled for.

No. of ICs used : 4

Learning from the project

  • Application of decade counter IC CD4017.
  • Application of the AND gate IC CD4081 for logic conversion. 
  • Application of the NE555 timer IC in the astable mode of operation. 
  • Application of relays and SCRs for switching operations.

Product description

Time keeping has been an integral part of educational institutions and big factories. Build this kit which will automatically ring, at preset times, to inform students and employees. This is a simple automation project which you can bring to your school.

Circuit operation

To begin time keeping and initiate the bell mechanism using the automatic school bell circuit, the peon needs to momentarily press switch S1 to mark the beginning of the first period. Thereafter, the bell sounds every 45 minutes to indicate the end of consecutive periods, except immediately after the fourth period, when it sounds after 30 minutes to indicate the completion of lunch break. When the last period is over, LED2 glows to indicate that the bell circuit should now be switched off manually. In case the peon has been late to start the school bell, the delay in minutes can be adjusted by advancing the time using switch S3. Each push of switch S3 advances the time by 4.5 minutes. If school closes early, peon can turn the bell circuit off by momentarily pressing switch S2.

The bell circuit contains timer IC NE555 (IC1), two CD4017 decade counters (IC2 and IC3) and an AND gate CD4081 (IC4). The NE555 (IC1) is wired as an astable multi-vibrator whose clock output pulses are fed to IC2. IC2 increases the time periods of IC1 (4.5 and 3 minutes) by ten times to provide a clock pulse to IC3 every 45 minutes or after 30 minutes, respectively. When the class periods are going on, the outputs of an IC3 switch on transistors T1 and T2 via diodes D4 through D12.

Resistors R4 and R5 connected in series to the emitter of NPN transistor T2 decide the 4.5-minute time period of IC1. The output of IC1 is further connected to pin 14 of IC2 to provide a period with a duration of 45 minutes. Similarly, resistors R2 and R3 connected in series to the emitter of NPN transistor T1 decide the 3-minute time period of IC1, which is further given to IC2 to provide the lunch-break duration of 30 minutes. Initially, the circuit does not ground to perform its operation when a 12V power supply is given to the circuit. When switch S1 is pressed momentarily, a high enough voltage to fire silicon-controlled resistor SCR1 appears at its gate.

When SCR1 is fired, it provides a ground path to operate the circuit after resetting both decade counters, IC2 and IC3. At the same time, LED1 glows to indicate that school bell is now active. When switch S2 is pressed momentarily, the anode of SCR1 is again grounded and the circuit stops operating. In this condition, both LED1 and LED2 don’t glow. When the eighth period is over, the Q9 output of IC3 goes high. At this time, transistors T1 and T2 don’t get any voltage through the outputs of IC2. As a result, the astable multivibrator (IC1) stops working. The school bell sounds for around 8 seconds at the end of each period. One can increase/decrease the ringing time of the bell by adding/removing diodes connected in series across pins 6 and 7 of IC1.

The terminals of the 230V AC electric bell are connected to the normally open (N/O) contact of relay RL1.

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.

Battery Low Indicator Save Rs. 75.00
Rs. 250.00
Rs. 175.00

Battery Low Indicator

Battery Low Indicator

by KNS Pvt Ltd
Save Rs. 75.00
Rs. 250.00
Rs. 175.00

The purpose of the battery low indicator is to give a visual indication when a battery has been discharged below a certain level. This is especially crucial for re-chargeable batteries that should not be discharged below a certain voltage level. This lower voltage limit depends upon the type of the battery. The battery low indicator circuit can be typically used for 12V batteries to give an indication of the battery voltage falling below the preset value. The indication is in the form of a flickering LED.

Learning from the project

  • Application of the LM319 dual comparator for level comparison.
  • Application of the NE555 timer in astable mode of operation.

Product description

The heart of the battery low indicator circuit is the dual comparator IC LM319 (denoted as IC1) which compares the battery’s voltage to a reference voltage level. Only one of the two independent comparators that are a part of the LM319 is used in the circuit. The two inputs to this comparator are:

  1. The reference voltage, which is applied to the non-inverting input pin (4). It is held constant at approximately 1.2V by the zener diode (D1).
  2. Battery’s voltage, which is applied via a potential divider arrangement built around resistors R2, R3, and preset VR1 and fed to the inverting input pin (5).

The corresponding output is generated at pin 12 of IC1. Preset VR1 is very important as it sets the voltage level at which a visual indication of the low battery level is generated. For example: If the battery under test is of 12 V and an indication is required as soon as the battery voltage falls below 10.5 V, the voltage at the inverting input (pin 5 of IC1) should be adjusted to 1.2 V using preset VR1.

Initially, when the battery is fully charged, the voltage at the inverting input (pin 5) of IC1 is higher than the non-inverting input (pin 4- voltage level held constant at approximately 1.2 V by D1). This causes the output at pin 12 of IC1 to remain low. The reset pin (pin 4) of an NE555 timer (IC2) is connected to the output pin of IC1 and hence, a low gets applied to it correspondingly. Since the reset pin is “active low”, the NE555 is reset continuously and oscillations are not generated at its output (pin 3). As a result, LED1 does not blink.

Considering the example values, when the battery voltage falls below 10.5 V, the voltage at the inverting input (pin 4) of IC1 becomes lower than the non-inverting input (pin 5) and the output at pin 12 of IC1 goes high. This applies a “high” to the connected reset pin of IC2 (NE555 timer) and the astable multi-vibrator built around IC2 starts generating oscillations. LED1 is connected to the output pin (pin 3) of IC2 and hence blinks to indicate low battery voltage and the battery needs to be charged before further use.

 

Click here to Download PDF

 

Biomedical Monitoring System with GSM Save Rs. 500.00
Rs. 5,000.00
Rs. 4,500.00

Biomedical Monitoring System with GSM

Biomedical Monitoring System with GSM

by KNS Pvt Ltd
Save Rs. 500.00
Rs. 5,000.00
Rs. 4,500.00

There has been an improvement in communication links and a lot of progress in advanced communication technologies in the recent years. In spite of this, there are few functioning commercial wireless monitoring systems, most of which are offline, and there are still a number of issues to deal with. There is a strong need for investigating the possibility of design and implementation of an interactive real-time wireless communication system. This project builds a generic real-time wireless communication system designed and developed for short and long term remote patient-monitoring, applying wireless protocol.

The primary function of this system is to monitor the temperature and heart beat of the patient and the data collected by the sensors are sent to the microcontroller. The microcontroller transmits the data over the air. At the receiving end, a receiver is used to receive the data and it is decoded and fed to a microcontroller, which is then displayed on the LCD display. If there is a dangerous change in patient status an alarm is also sounded.

Brand: HBeonLabs, Product assembled by HBeonLabs

 

Click here to Download PDF

 

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

 

Cellphone Detector Mobile Bug Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Cellphone Detector Mobile Bug

Cellphone Detector Mobile Bug

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

Summary

This handy, pocket-size mobile transmission detector can sense the presence of an activated mobile phone from distance of one and- a half meters. So it can be used to prevent the use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorized video transmission.

Learning

Things which you can learn:

*Working of CA3130 as current to voltage converter.
*Application of transistor as an amplifier.
*Application of NE555 as an amplifier.

Product Description

Build yourself a mobile detecting bug and become an expert in finding out hidden mobile phones in sensitive areas like LPG godown etc.

Working:

The circuit can detect both the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode.The circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone.The disk capacitor along with the leads acts as a small gigahertz loop antenna to collect the RF signals from the mobile phone.

Op-amp IC CA3130 (IC1) is used in the circuit as a current-to-voltage converter with capacitor C3 connected between its inverting and non-inverting inputs.

When the mobile phone signal is detected by C3, the output of IC1 becomes high and low alternately according to the frequency of the signal as indicated by LED1. This triggers monostable 555timer.

 

Click here to Download PDF

“What’s Included In This Box”.

 

S.No Component Quantity
1   Capacitor 22pF ceramic 2
2   Capacitor 0.22uF ceramic 1
3   Capacitor 100uF 25V electrolytic 1
4   Capacitor 47pF ceramic 1
5   Capacitor 0.1uF ceramic 2
6   Capacitor 0.01uF ceramic 1
7   Capacitor 4.7uF 25V electrolytic 1
8   IC CA3130 1
9   IC NE 555 1
10   LED RED 1
11   Piezzo Buzzer 1
12   Resistor 2.2M 2
13   Resistor 100K 1
14   Resistor 1K 1
15   Resistor 12K 1
16   Resistor 15K 1
17   Tr BC548 1
18   switch on/off 1
19   8-pin base 2
20   Antenna 1
21   PCB - AB4380 - Cell Phone Detector 1

 

Cellphone Operated Land Rover Save Rs. 550.00
Rs. 2,750.00
Rs. 2,200.00

Cellphone Operated Land Rover

Cellphone Operated Land Rover

by KNS Pvt Ltd
Save Rs. 550.00
Rs. 2,750.00
Rs. 2,200.00

Summary

A robot is an electromechanical system that has an ability to interact with the physical environment and can be programmed to do specific tasks accordingly. All robots shares features including controlled mechanical and movable structures. The controlling of a robot includes three distinct phases: Perception (Sensing) is mounted on the robot, Processing is done through on board microcontroller or processor, Action is performed by using motors or actuators. The Cell Phone Operated Land Rover implemented here is basically controlled by a mobile phone that makes a call to the mobile phone connected to the rover itself.

In the course of a call, if any button is pressed, a tone corresponding to the pressed key is heard at the other end of the call. This tone is called ‘dual-tone multiple-frequency’ (DTMF) tone. The robot perceives this DTMF tone with the help of the phone stacked onto its body and the DTMF decoder. The received tone is processed by the ATmega16 microcontroller (Preprogrammed) with the help of this DTMF decoder MT8870, decodes the DTMF tone into its equivalent binary digit and is sent to the microcontroller.

The microcontroller takes a decision for any given input and outputs its decision to motor drivers in order to drive the motors for forward or backward motion or a turn. The cell phone in the robot acts as a remote. Hence, this simple robotic project does not require the construction of receiver and transmitter units. Some of the main components used are: MT8870 DTMF decoder, AVR ATmega16 micro-controller,L293D motor driver and 74LS04 NOT gate.

Learning

Things which you will learn:
*Learn basics of robotics!
*Learn the application and inter facing of the DTMF decoder MT8870 with the ATmega16 micro-controller.
*Learn the application and interfacing of the H-bridge motor driver IC L293D.

Product Description

Robots are always a cool toy for DIYs, hobbyist and engineers. Wouldn't it be fun if the same robot is controlled by your mobile phone sounds interesting right?. So here is the a robot kit which works on the principle of "DUAL TONE MULTI FREQUENCY"(DTMF) to help control the robots motion.

Working

In order to control the movement of the Cellphone Land Rover, a phone call needs to be made from the operator’s cell phone to the cell phone mounted on top of the land rover. This rover-mounted phone is responsible for providing the DTMF tone inputs to the MT8870 decoder IC which is a part of the control circuitry. This connection between the rover-mounted phone and the main circuit (PCB) is achieved through a pair of headphones (also commonly known as the “hands-free” kit). Once the call made from the operator’s phone is received at the rover’s end, any key maybe pressed on the operator’s phone to control the actions performed by the land rover.

The DTMF tones produced by each such button-press are received by the rover-mounted phone through the call-connect. These tones are further fed to the control circuit by the headset connected to the rover-mounted cell phone. The MT8870 decodes the received tone and sends the equivalent binary number to the microcontroller’s port A (input port). According to the program burned into the microcontroller, the rover will move in a direction corresponding to this input. For example, when key ‘2’ is pressed on the operator’s mobile phone, its binary equivalent (0000 0010) is generated by the DTMF decoder IC. These bits are then inverted (i.e. 0000 0010 becomes 1111 1101) and fed to the input port A of the microcontroller. Consequently, the output generated at output port D is 1000 1001 (binary notation) i.e. port pins PD0, PD3 and PD7 are raised high. The high output at PD7 of the micro-controller drives the motor driver IC (L293D). Port pins PD0 and PD3 drive, motors M1 and M2 in the forward direction. Similarly, motors M1 and M2 move together to generate left, right, backward and stop condition motions.

Note: It is preferable to keep the rover-mounted phone in the “auto-answer” mode. If the cell phone being used does not support the auto answering facility, the call would have to be received manually by pressing the “OK” or “answer” key. The call should be transferred to the hands-free mode so that the DTMF tone can be passed onto the input of the MT8870 decoder in the control circuit through the “tip” and “ring” connection terminals provided on the PCB.

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

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

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

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.

Digital Voltmeter Save Rs. 100.00
Rs. 600.00
Rs. 500.00

Digital Voltmeter

Digital Voltmeter

by KNS Pvt Ltd
Save Rs. 100.00
Rs. 600.00
Rs. 500.00

Summary

Build yourself an awesome voltmeter which you can use it to measure and troubleshoot your project. Great kit for those who are looking to learn on the Analog to digital conversion concepts. A voltmeter finds application wherever voltage is to be measured. The Digital Voltmeter is designed as a panel meter and can be used in DC power supplies panels or where it is necessary to have an accurate indication of the voltage. No. of ICs used: 3

Learning

Things which you can learn:
*Application of positive and negative voltage regulator ICs.
*Application of the analog to digital converter IC ICL7107.
*Voltage measurements technique
* Linear Integrator
*Comparater

Product Description

The heart of the Digital Voltmeter circuit is an analogue-to-digital converter IC i.e. the ICL7107. This IC incorporates in a 40-pin case all the circuitry necessary to convert an analog signal into digital and can drive a series of four seven-segment LED displays directly. The circuits built into the IC are an analogue-to-digital converter (ADC), a comparator, a clock, a decoder and a seven-segment LED display driver.
The circuit can display any DC voltage in the range of -1999 volts to +1999 volts. It operates off ±5 volts.

Working

The operation of the circuit is described in two stages. During the first stage, for a given period the input voltage is integrated, and the output of the integrator at the end of this period is a voltage which is directly proportional to the input voltage. At the end of the preset period, the integrator is fed with an internal reference voltage and the output of the circuit is gradually reduced until it reaches the level of the zero reference voltage. This second phase is known as the negative slope period and its duration depends on the output of the integrator in the first period. As the duration of the first operation is fixed and the length of the second is variable, it is possible to compare the two and this way the input voltage is in fact compared to the internal reference voltage and the result is coded and sent to the display.

Basically, the voltage to be measured is applied across points ‘IN-L’ and ‘IN-H’ of pins 30 and 31 of IC1, respectively, through circuit resistors R5, R6, R7 or R8 and preset VR1. Resistor R2 together with C5 forms the RC circuit used to set the frequency of the oscillator (clock), which is set at 48 kHz approximately. At this clock rate, there are about three different readings per second. Capacitor C4, which is connected between pins 33 and 34 of IC1, compensates for the error caused by the internal reference voltage and also keeps the display steady. Capacitor C2 and resistor R1 together forms the circuit that does the integration of the input voltage and at the same time prevents any division of the input voltage making the circuit faster and more reliable. Capacitor C1 forces the instrument to display zero when there is no voltage at its input. Resistor R3 together with reference control preset VR2 is used to adjust the instrument during set-up so that it displays ‘0’ when the input is zero. Resistor R4 controls the current that is allowed to flow through the displays (for decimal point) so that there is sufficient brightness without damaging them.

The IC, as mentioned earlier, is capable of driving four common-anode, seven-segment displays. Displays DIS1 through DIS3 are connected such that they can display all the numbers from ‘0’ to ‘9,’ while display DIS4 can display only the digit ‘1’ (and ‘-’ sign when the voltage is negative). When TEST switch is pressed, test pin is pulled high (to V+) and all segments turn on to show ‘1888’ on the display. The TEST pin will sink about 15 mA under this condition. In the lamp test mode, the segments have a constant DC power supply. Pin 36 (REF HI) is made high through VR2 to adjust the reference voltage and pin 35 (REF LO) is connected to the negative terminal of the input. Preset VR1 is used to adjust the range of voltage divisions. Resistors R5, R6, R7, and R8 connected to pin 31 are used for range selection. Switch S2 is two-pole, four-position (each ganged) rotary switch. The decimal point is connected to resistor R4 via rotary switch S2 for different range selection.

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

Summary

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

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

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

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. Now 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

 

DTMF Based Home Security System Save Rs. 500.00
Rs. 4,000.00
Rs. 3,500.00

DTMF Based Home Security System

DTMF Based Home Security System

by KNS Pvt Ltd
Save Rs. 500.00
Rs. 4,000.00
Rs. 3,500.00

Summary

DTMF based home security used to secure our home from unauthorized person.

Learning

Embedded system

Product Description

Security prime concern in our day to day life.The microcontroller based digital lock presented here is an access control that allows, only an authorized person to access a restricted area.This system is based suitable for corporate offices, ATMs, home security. As a simple example, to lock our mobile phones keypads, a security code of at least 4 digits must be entered.

The system comprises a small electronic unit with a mobile keypad which is outside the entry door to control a solenoid-operated lock with help of D.C. motor. When an authorized person enters the predetermined password via the hand held mobile keypad from some other place, the stepper motor is operated for a limited time to unlatch the solenoid operated lock so the door can be open. At the end of the preset delay, the stepper is operated in the reverse direction and door gets locked again.

Brand: HBeonLabs Technology Pvt. ltd., Product assembled by HBeonLabs

 

Click here to Download PDF