Best Musical Instrument for Karaoke Freaks

For many people, Karaoke parties spell fear in their minds. You could be singing off key, you might not remember the lyrics and appear dumb or you might lack the courage to stand in front of the crowd to let your freak flag fly. Many things could go wrong, but not you have one of the best musical instruments with you for the party. The STVG-519 singing machine is the magic formula for making your singing parties fun and successful.

The STVG-519 singing machine is a multipurpose system that will revolutionize your entertainment experience. Its best rating stems from its improved utility, versatility and user-friendliness. Even better, you will be handling a lightweight music system and so moving about should be stress-free. Setting up it up is also easy-peasy.

So what features make the Singing Machine STVG-519 one of the best musical instruments?

The ability to play both CD and CD+G. To streamline this utility and ensure the hype is real, the Singing Machine STVG-519 comes with two microphones (wired) and a generously wide LED track display. To help you know the words and get in sync with the melody, the 5.5-inch monitor will be displaying lyrics for the songs you play. All that will be needed from you is a connection with the rhythm.

The built-in screen is the latest addition available in only the best musical instruments. This is greatly beneficial since you won’t have to rely on another display device such as a computer or TV to read your lyrics during a party. However, thanks to the versatility of this musical instruments, you can still use the audio and video auxiliary to hook the lyrics to a TV or a bigger screen if you like.

What’s more, there is the option to plug in your auxiliary jack and enjoy mp3 or mp3+G songs from your phone or tablet. This way friends and family will taste a variety from your limitless music menu. This inclusion is much need, considering CDs have a few numbers of tracks and that re-loaded tracks get outdated fast with time.

As one of the best musical instruments in the market, you can expect multiple ways to play your songs with the Singing Machine STVG-519. For starters, its built-in speakers are loud enough and high resolution. But you can also connect this musical instrument to a TV via the complimentary RCA cables. To set your pace and rhythm, the LED track display has controls to help you make adjustments to the songs when they play.

Karaoke’s are all about fun, talent and socializing. The best musical instruments for Karaoke, therefore, should give you an option to sing with your friends or solo if you like. Luckily for you, you don’t have to look too hard, the STVG-519 Singing Machine contains this feature. There are two wired microphones slots for this purpose. Then again, this singing machine is compatible with wireless microphones. That should enhance your mobility when doing a duet.

The best musical instruments need to have full options for voice control. In this case, automatic controls are better. Singers can then play around with the features for voice control, balance and mute among others. You can choose to silence your voice and give prominence to the music in the background or you can adjust your tone and pitch to suit the mood of the party.

For a whole new musical experience, the STVG-519 Singing Machine also has voice controls that include echo and balance effects. There is also the auto-fade controls that allow you adjust pre-recorded vocals before chiming in.

The design and feel of the STVG-519 Singing Machine will surpass your expectations. It is compact and lightweight (11pounds). This musical instrument entails a black and silver finish. It has dimensions of 11.3 by 12.6 by 17.4 inches. The STVG-519 singing machine resembles other musical instruments.

In summary, benefits of the STVG-519 Singing Machine over others including:

  • High versatility; you can play music from your mobile devices
  • You can play a CD and read lyrics at the same time
  • Extensive voice control features
  • Vocal enhancement features to help you sound like a pro

The STVG-519 Singing Machine is a musical instrument that you can purchase for the purpose of having fun with it at home. However, if you are hosting a karaoke party, you won’t get disappointed in it either. The features as mentioned above will go a long way in ensuring you have a memorable party.

Feel The Music with The Best Headphones

When it comes to noise, it’s pretty much unavoidable. From the birds with their range of songs in the morning, loud honks as vehicles try to navigate the streets, to construction materials rumbling through the day. However, every now and then you need to lock out the world, even for a moment. While you may not be able to afford tickets to a deserted island, you could get a pair of headphones, and lock out the world while enjoying some close and personal sounds to soothe you.

Headphones deserve to win man’s best innovation competition or at least be in the running for the award. Headphones have solved a myriad of problems and as little, as they may be, it is hard to envision life without them, especially when you start getting used to them.

Like everything else made by man, here’s what stands out, what is on the average, and what’s straight up deplorable. Headphones are no exception. Here, the focus is on the best headphones in the market, and while best is argumentative, you will agree the below headphones have made their way to your ears and the top pics.

Before getting to the list, it’s important to look at the process followed to determine the best headphones from the rest. Here’s what makes headphones stand out;

1. Active Noise Cancelling Feature

Reasons for having headphones vary from person to another, you may want to cancel out the noise around you, or you may just want to peacefully listen to music without external disruptions. Whichever the case may be, locking out the noise is an important part of the best headphones.

Active Noise Cancelling (ANC) headphones are those that have one or more microphone whose function is to measure the noise level around the cans. After the noise has been measured, customized electronics create sound waves which block the ambient noise. Passive Noise Cancelling (PNC) headphones, on the other hand, are headphones whose ear cups partially block the ambient noise. Headphones with denser foam will block out the more external noise.

2. Durability

Most modern headphones are chargeable. While this may be a good thing, it also limits how long you can listen through the headphones. The charge can normally range anywhere where from 15 hours to 40 hours. It’ll be long before you exhaust the charge, but when you do, it may be through your jam, and no one wants that.

Other features looked at include; price, Bluetooth and touch control functionalities. And now for the list:

First off, in the category of the best headphones overall headphone is the Bose QuietComfort 35 II. The headphone fits over your eras, has microphone functionality, is enables with Bluetooth and has a 20-hour battery life. The headphones efficient ANC functionalities and have added a Google Assistant Button, ideal for quick inquiries about issues such as new restaurants nearby or the weather.

They are going for $349.

In the best headphones under $200 category, the Sennheiser HD 4.50 headphones clinched the title. Apart from being pocket-friendly, they are also fitted with a microphone, Bluetooth and the battery life will last for around 19 hours. The headphones have a sleek design, are comfortable and the audio quality can only be described as clean and precise.

The headphones are retailing at $173.51

In the best headphones over-ear category, the Bowers & Wilkins PX Headphones took the trophy. The headphones are fitted with a microphone and Bluetooth and coasts a battery life of 22 hours. Furthermore, if you prefer quiet music, the PX has a companion app that allows you to adjust the ANC modes, and determine how much ambient noise to let in.

They are retailing at $399

In the best headphones on-ear, Bose QuietComfort3 Headphones took the day. As per any other great headphones, they are super light, weighing at 4.8 ounces and are fitted with a microphone and but they lack the Bluetooth functionality. The battery life is a whopping 25 hours. The sound quality is best described as turnkey.

They are retailing at $349.

In the best headphones continuous audio, Plantronics Backbeat Pro2 came out on top. They have active noise canceling functionalities that are setting the industry’s benchmark and are fitted with both a microphone and Bluetooth. The battery life extends to 24 hours and unlike most of the competition, the sound quality is clear, unlike most of the competing brands which have a slight white hiss.

They are retailing at $182.97

In the best premium headphones, Sennheiser Momentum Wireless Headphones are unrivaled for the first position. They are fitted with both a microphone and Bluetooth and other than seamless design, have up to 22 hours of juice in the battery. The headphones are available both as on-ear and over-ear. On the design part, they are made from both stainless steel and leather, giving them that perfect finish.

They are retailing at $399.

For Designing Versatile Integrated Circuits

One of the most popular freeware for layout and design, LASI is amazingly versatile as it can be used with various electronic components like ICs, MEMS, PC boards and project documentation drawings. In its latest version, tooltips have been turned off for better user experience on Windows and some more updates.

LASI is a conventionally preferred module since the times of Win32, and its various updated versions have been quite popular across Windows Vista, XP and now Windows 7. It can also be accessed on Linux operating systems using Wine translator. There are, however, some user limitations in the Linux version.

What makes it such a favourite is the fact that drawings are composed on hierarchical individual cells called Transportable Layout Cells (TLCs), which are flexible for transfer between different drawings and are in basic XML format.

Fig. 1: Design layout using TLCs in LASI (Image source: http://www.vlsitechnology.org)

Along with the main editor for drawing, it comprises a lot of other utilities including DRC programmable bitmap, and a compiler that helps to extract Spice circuit files from schematic and layout format.

Drawings made in LASI can also be archived as GDS as the drawing pattern for LASI and GDS is similar. Later, in case LASI is unavailable, drawings can also be transferred to CAD, since CAD systems support GDS.

Complete circuit diagram
Fig. 2: Complete circuit diagram (Image source: http://www.freebyte.com)

New features of LASI 7

For better and enhanced user experience, changes have been made to the main editor and a few utility tools. Tools not required have been turned off as these often cause unnecessary redraws on some versions of Windows. To include the recently made changes, add-on tools have been recompiled.

Lasi tools and utilities
Fig. 3: LASI tools and utilities (Image source: https://i.ytimg.com)

Users can now hide or unhide ‘tooltips’ section, depending upon usability, using the Cnfg command and also by checking and unchecking the tooltips button.

A lot of minor changes have also been made in the help feature for files and web pages.

Download Latest Version of the software


Latest Sensors & Their Applications

The latest sensors, including those used in IoTs and wearables, are soon going to revolutionise electronics industry. Be it a silent heart attack detector that detects the protein level of a patient or a posture-correcting chair that alerts the occupant sitting in a wrong posture—both recently invented by Indian teenagers—sensors have a vital role to play in electronic devices. The fact is that the application of sensors is ever-expanding along with the progress in science and technology.

As per industry reports, sensors are becoming the biggest and fastest growing markets, comparable with computers and communication devices markets. You find sensors in smartphones, automobiles, security systems and even everyday objects like coffee makers! Apart from consumer electronics, these are also an integral part of the Internet of Things (IoT), medical, nuclear, defence, aviation, robotics and artificial intelligence, agriculture, environment monitoring and deep-sea applications.

The shift to smarter sensors

Basically, a sensor is an input device that receives and responds to a signal or stimulus. Nowadays some sensors come integrated with many sensing elements and read-out circuitry in a single silicon chip, providing high accuracy and multiple functions. Manufacturers use both advanced technologies and methods for signal processing and conversion. Latest sensors have more features including user-friendliness, accessibility and flexibility. So there is a paradigm shift in the sensor industry with integration of new technologies to make sensors smarter and intelligent.

Ordinary sensors are still used in many applications. But innovation and advancement in microelectronics is taking sensor technology to a completely new level. The functionality of ordinary sensors has expanded in many ways and these now provide a number of additional properties. The Latest Sensors are becoming more and more intelligent, providing higher accuracy, flexibility and easy integration into distributed systems.

Intelligent sensors use standard bus or wireless network interfaces to communicate with one another or with microcontrollers (MCUs). The network interface makes data transmission easier while also expanding the system. Manufacturers can diagnose sensor faults and guide users to troubleshoot them remotely through the computer network.

An intelligent sensor may consist of a chain of analogue and digital blocks, each of which provides a specific function. Data processing and analogue-to-digital conversion (ADC) functionalities help improve sensor reliability and measurement accuracy. The typical structure of an intelligent sensor is shown in Fig. 1.

Intelligent sensor structure
Fig. 1: Intelligent sensor structure (Courtesy: www.mdpi.com)

Common types of latest sensors

There are a wide variety of sensors depending on the technology (analogue/digital) and applications. This article covers some of the latest sensors including IoT sensors, pollution sensors, RFID sensors, image sensors, biometric sensors, printed sensors, and MEMS and NEMS sensors.

IoT sensors

IoT sensors include temperature sensors, proximity sensors, pressure sensors, RF sensors, pyroelectric infrared (PIR) sensors, water-quality sensors, chemical sensors, smoke sensors, gas sensors, liquid-level sensors, automobile sensors and medical sensors.

These latest sensors are connected to a computer network for monitoring and control purposes. Using sensors and the Internet, IoT systems have wide applications across industries with their unique flexibility in providing enhanced data collection, automation and operation.

The global market for IoT sensors reached $7.3 billion in 2015. It is expected to reach $47.8 billion in 2021 from nearly $10.6 billion in 2016, growing annually at 35 per cent during 2016-21. The Asia-Pacific market for IoT sensors is expected to grow from $3 billion in 2016 to $14 billion in 2021 at a CAGR of 36.1 per cent from 2016 through 2021.

Pollution sensors

Air pollution sensors are used to detect and monitor the presence of air pollution in the surrounding area. These can be used for both indoor and outdoor environments. Although there are various types of air pollution sensors, most of these sensors focus on five parameters: particulate matter, ozone, carbon monoxide, sulphur dioxide and nitrous oxide. These sensors are somewhat costly but are becoming more affordable for common use.

Sensors capable of detecting particulate matter with a diameter between 2.5 and 10µm (PM10) and a diameter less than 2.5µm (PM2.5) are available in the market. Fig. 2 shows a typical PM sensor popular among hobbyists and experimenters. Fig. 3 shows an easy-to-assemble PM2.5 sensor from Sharp Corporation with a detection time of ten seconds.

PM2.5/PM10 sensor |latest sensors
Fig. 2: PM2.5/PM10 sensor (Courtesy: http://aqicn.org)
PM2.5 sensor
Fig. 3: PM2.5 sensor (Courtesy: www.digikey.com)

RFID sensors

RFID chips (Fig. 4) as small as the size of rice grains can be inserted directly under the skin for use as ID cards. There is a trend to use RFID chips in many products including contactless banks cards and Oyster cards. There are also cases where chips are implanted in pets and cattle for monitoring.

Grain-size RFID chip | latest sensors
Fig. 4: Grain-size RFID chip (Courtesy: https://voiceofpeopletoday.com)

Wearable sensors

These latest sensors include medical sensors, GPS, inertial measurement unit (IMU) and optical sensors. With modern techniques and miniature circuits, wearable sensors can now be deployed in digital health monitoring systems. Sensors are also integrated into various accessories such as cloths, wrist bands, eyeglasses, headphones and smartphones. An IDTechEx report forecasts optical, IMU and GPS sensors to dominate the sensors market in terms of revenue by 2022 (Fig. 5).

Wearable chart
Fig. 5: Wearable chart (Courtesy: www.idtechex.com)

Interfacing Laser Diode with Arduino Uno

There are various ways to interface a laser with Arduino depending on the application. A laser diode finds applications in CD/DVD reading and recording, optical-fibre communications, laser printing and scanning, laser pointers, directional lighting, barcode readers and so on. A laser diode can be interfaced with Arduino Uno using photoresistors, photodiodes, phototransistors or similar sensors and detectors.

Fig. 1: A laser pointer

Laser diodes and modules are available in various sizes and shapes. For example, a 3V to 5V DC, 5mW laser module is available in a metal case (Fig. 1). It produces a laser of about
650nm wavelength and a tiny red dot. It comes with three 1.5V button cells. Remove the cells and connect two wires: the positive wire to its body and the negative to the spring inside it. Connect the positive terminal to any one of the digital pins of Arduino board, and the negative wire to GND pin. Write a simple sketch (software) to turn on/off the laser torch through Arduino board.

Laser modules like KY-008 (Fig. 2) can also be connected directly to Arduino digital pins. This module can draw a current up to 30mA only, so it can be directly powered from an Arduino board.

KY-008 laser module
Fig. 2: KY-008 laser module

You may refer to the use of KY-008 laser module with Arduino from the following link: click here

This link gives not only pin connection details but also Arduino code. You can also interface SF02 module directly with Arduino. SF02 is a lightweight laser rangefinder used for distance measurements ranging from 0 to 50 metres. Another interesting laser module from STMicroelectronics is VL53L0X. It works off 2.6-3.5V operating voltage and has I2C interface.

What are the different types of lasers available in the market?

Types of lasers

There are many types of lasers available for various applications. Depending on the lasing medium used, these are solid-state, gas, excimer, dye or semiconductor lasers.

• Solid state lasers emit infrared light at 1.064 micrometres.
• Gas lasers have a primary output of a visible red light. CO2 lasers emit energy in the far-infrared 10.6 micrometres, and are used for cutting hard materials.
• Excimer lasers produce light in the ultraviolet range.
• Dye lasers are tunable over a broad range of wavelengths.
• Semiconductor lasers are generally very small and use low power. These are used as the writing source in some laser printers, CD/ DVD players and the like.


Wind Power: The Global Impact

“Of all the forces of nature, I should think the wind contains the largest amount of motive power—that is, power to move things. Take any given space of the earth’s surface—for instance, Illinois; and all the power exerted by all the men, and beasts, and running-water, and steam, over and upon it, shall not equal the one hundredth part of what is exerted by the blowing of the wind over and upon the same space. And yet it has not, so far in the world’s history, become proportionally valuable as a motive power. It is applied extensively, and advantageously, to sail-vessels in navigation. Add to this a few windmills, and pumps, and you have about all. …As yet, the wind is an untamed, and unharnessed force; and quite possibly one of the greatest discoveries hereafter to be made will be the taming and harnessing of it.” —Abraham Lincoln

Globally, there is a huge emphasis on encashing the energy generation possibilities of renewable sources, especially wind. Wind power offers a sustainable option in the pursuit of renewable energy. In this article, we explore how wind energy is being utilised in different parts of the world.

A case study from Canada

Wind power promises to be more beneficial than any other existing source of energy. It doesn’t produce any undesirable and harmful waste, harnesses the power of nature (wind), and is one of the best alternatives to the burning of coal/gas or use of nuclear energy.

The Wolfe Island Wind Project in Canada aimed at meeting electricity needs of residents in Kingston, Ontario, through wind power. As part of the project, 86 turbines were placed in the wind farm with an investment of around 410 million dollars to generate sufficient electricity for 75,000 homes. The returns for the same were spread over 20-25 years.

Costs and benefits

Turbine generators for the project cost 1500-2000 dollars per kilowatt. Using 86 turbines of 2.3MW capacity with a total cost of 410 million dollars, the project cost a little more than 2000 dollars per kilowatt.

The wind power cost eight cents to 10.2 cents per kilowatt-hour, which was much higher than the actual electricity price in Canada (1.2 to 7.8 cents per kilowatt-hour, depending upon the location). On adding other costs like admin, marketing and distribution, it came to a total of 3.2 to 11.8 cents.

The above calculation led to a conclusion that wind power comes with a premium price. To overcome price limitations, the Canadian government provided some subsidies and incentives like one per cent of tax benefit per kilowatt hour (kWh) of electricity produced using wind power.

Thus it can be concluded that wind power still has a long way to go before mass adoption as the turbine cost has to come down. Not all governments can afford such a technology.

The case for India

India was among the first few countries in the world to establish the Ministry of New and Renewable Energy (MNRE). In the last two decades, the country has witnessed unprecedented growth in its wind power generation capacity from about less than 1GW (gigawatts) to more than 32.72GW till October 2017. India has the fourth largest installed wind power generation capacity in the world.

Evolution of the Indian wind sector | Wind Power
Fig. 1: Evolution of the Indian wind sector (Source: Ministry of New and Renewable Energy (2015b))

Of the total installed capacity for renewable energy generation, wind power accounts for about 10 per cent. It is seen that two-thirds of production happens between May to September months, coinciding with Monsoons. One of the major reasons behind the increase of wind power through the years has been the benefit of accelerated depreciation for businesses.

The levelised tariff for wind power reached an all-time low of ₹ 2.64 per kWh during bidding for various wind power development projects in October 2017. Previously, the bid rate was ₹ 3.42 per kWh in August 2017 in an auction by TANGEDCO (Tamil Nadu Generation and Distribution Corporation).

Renewable energy capacity additions and share of wind power
Fig. 2: Renewable energy capacity additions and share of wind (Source: Central Electricity Authority Report—Growth of Electricity Sector in India 1947-2013, FY 14 values as per MNRE)

The MNRE has set a target of producing about 60,000MW of wind power by the year 2022. To achieve this ambitious target, the government plans to enter into offshore wind power generation. It plans to set up the first plant along the Gujarat coast.

To conclude

At the end of 2006, worldwide capacity of wind-powered generators was 73.9GW. Although it is believed that wind power presently produces a little above one per cent of world’s electricity demand, it contributes around 20 per cent in Denmark, about 9 per cent in Spain and roughly 7 per cent in Germany. Around the world, wind power generation more than quadrupled between 2000 and 2006. There are many thousands of wind turbines operating, with a total capacity of 73,904MW, of which Europe accounts for 65 per cent (2006).

The most amazing part of wind power generation is no greenhouse gas emission. However, to derive the maximum benefit, wind power projects should be undertaken with long-term planning. To justify the heavy investment and variable output, these must be combined with other renewable technologies like reservoir-based hydro and gas plants.


Mini Fridge With Peltier Modules

It was in the middle of 1821 when J.T. Seebeck discovered that if two dissimilar metals connected at two different points are held at different temperatures, a microvoltage develops. This phenomenon is called Seebeck effect. Some years later, Peltier discovered that if a voltage is applied to a thermocouple, one junction of the thermocouple heats up while the other cools down. Opposite of the Seebeck effect is called the Peltier effect.

This guide to designing a little solid-state cooler engine is centered on the commonly available Peltier chip. A Peltier chip is a thermo-element that utilises the Peltier effect to implement a heat pump. It has two plates, one cold and the other hot. Between the plates there are several thermocouples connected together. If a proper voltage is applied, one plate becomes cold and the other plate becomes hot.

The Peltier chip is called a heat pump because it neither generates heat nor cold. It just transfers heat from one plate to another, thus cooling the first plate. It is also popularly called thermoelectric cooler (TEC) chip. In short, by applying a direct current (DC) to the TEC chip, temperature differences are generated between the front and back of the device (Peltier effect), and you end up with a hot and a cold surface. TEC1-12706 is a common thermoelectric cooler chip available from most eBay traders.

In TEC1-12706, the letter C after TE indicates ‘standard size,’ and 1 indicates ‘one-stage’ TEC. Right next comes a dash. After the dash, the first three digits indicate the number of thermocouples inside the TEC. Here, it has 127 couples. Next two numbers indicate operating current rating for the Peltier. So, 06 denotes ‘6 amperes.’

Peltier cooler

A Peltier cooler is a cooler engine comprising a Peltier element (TEC chip). When a direct current is passed through a TEC chip, the low-temperature side absorbs heat and the high-temperature side emits heat, creating a temperature difference across the two surfaces. However, since the heat emitted is more reactive to the amount of electricity input into the module than the heat absorbed, if a direct current is continuously passed through the chip the emitted heat exceeds the absorbed heat and both sides of the unit become hot. Because of this, it is crucial to connect the TEC chip to a radiator such as aluminium fins to efficiently disperse the emitted heat.

In short, when DC voltage is applied to the TEC chip, positive and negative charge carriers in the pellet array absorb heat energy from one substrate surface and release it to the substrate at the opposite side. The surface where heat energy is absorbed becomes cold, and the opposite surface where heat energy is released becomes hot!

The Peltier cooler also includes a powerful heat-sink/fan combination to cool the TEC chip. Table below depicts specifications of a TEC1-12706 thermoelectric cooler chip. You can buy a CPU heat-sink and fan unit with almost the same specifications as the CPU fan for AMD processors: 80.6×80.6×69.4mm3 with aluminium fin heat-sink. The additional 60×60mm2 aluminium heat-sink plate (and thermal grease) is also available at reasonable price. Fortunately, you can buy most of these key components from prominent eBay and/or Amazon sellers (see Fig. 1).

Fig. 1: Key components for DIY Peltier cooler

TEC chip and basic test

Before starting an actual construction with a TEC chip, test it for proper working condition. For that, just connect the red (+) and black (-) wires of the TEC chip (TEC1-12706) to a 1.5V DC lab power supply and keep the power supply on for 10 to 30 seconds. Thereafter you can test the TEC chip using your fingertip or digital thermometer to ensure that one side of the chip is hot and the other side cold. Just mark down hot and cold faces of the TEC chip (for example, with letters H and C) using any permanent marker pen.

Testing the TEC chip
Fig. 2: Testing the TEC chip

Powering up

The assembled cooler engine (thermoelectric cooler chip, heat-sink and cooling fan, all assembled) can be powered from a 12V, 6A+ switch-mode power supply (SMPS) unit/module, like the one shown in Fig. 3. Else, try a 12V/7Ah SMF battery. If everything is okay, you will see traces of frost appearing on the plate within seconds.

6A-8A, 12V switch-mode power supply
Fig. 3: 6A-8A, 12V switch-mode power supply

Note that the primary function of a Peltier chip is cooling, and Peltier chips have different power ratings corresponding to how fast the cold side is able to cool down an object. Another factor generally specified is delta-T (dT), which is the maximum difference between temperature on both sides.

Further, Peltier chips don’t function as per specifications, unless there is something to help in taking the heat out from the hot side. That’s why a beefy heat-sink is called for. It’s the ambient air with its temperature where heat is dissipated.

Increase the Number Of Appliances Control In RF Based Circuit

In this project, we look to solve the problem of the number of appliances being operated using a microcontroller. Generally, this number is restricted to 3 or 4, with this project in action, it can be increased up to 1 appliances. When we make appliances control by RF (ASK) module we control only 4 appliances, but we can control up to 16 appliances because the ICs used in transmitter and receiver sections (HT12E & HT12D) convert BCD parallel data into serial data.

Since it can take BCD input, we can give 24=16 different type of input and it can be decoded at the receiver section very easily.

At transmitter section, we have used 74C922 IC to get BCD output on pressing any button of the keypad matrix and at the receiver section, we use 74LS154 IC to decode each BCD code into the corresponding output.

Author’s Prototype

Component Required For Transmitter

S.NO. COMPONENT NAME QUANTITY
1 4*4 matrix keypad 1
2 74C922 IC 1
3 0.1 uf capacitor 2
4 1 uf capacitor 1
5 Led 1
6 Resistor(330ohm) 1
7 HT12E IC­­­­­­­­­­­­­­­­­­­­­­­­­­ 1
8 RF(ASK) TRASMITTER 1
9 Resistor(1.1M) 1
Circuit Diagram for Transmitter
Circuit Diagram for Transmitter

Component Required For Receiver

S.NO. COMPONENT NAME QUANTITY
1 Ask RF Receiver 1
2 HT12D IC 1
3 Resistor(51K) 1
4 Resistor(10K) 1
5 BC548 transistor 1
6 Resistor(470ohm) 1
7 Led 17
8 74LS154 IC 1
9 Resistor(330 Ohm) 16
Circuit Diagram for Receiver
Circuit Diagram for Receiver

Since the signal received at the receiver is active low, till the push button is pressed at the transmitter section, to control appliances by this signal we must make another circuit that will convert the single pulse into a continuous form. This will be used to drive relay and control the appliances.

Components required for stable multivibrator

S.NO. COMPONENT NAME QUANTITY
1 4017 IC 1
2 BC558 transistor 1
3 0.1 uf capacitor 1
4 Resistor(220K) 1
5 Resistor(470 ohm) 2
6 Led 2
7 Resistor(1K) 1
8 BC548 transistor 1
9 IN4007 diode 1
10 Relay(5v,100 ohm) 1
Circuit for bistable multivibrator using 4017
Circuit for bistable multivibrator using 4017

Circuit operation

  1. When we press any button, the 74C922 IC converts that signal into BCD parallel form.
  2. HT12E encodes that parallel BCD data into Serial data, which is then given to RF transmitter module for transmission.
  3. The RF receiver module receives that data and sends it to HT12D. It converts that data from serial to parallel (BCD conversion).
  4. 74LS154 IC (4*16 decoder) decodes the BCD data into its corresponding signal.
  5. A bistable multivibrator circuit is connected at each output of 74LS154 IC. This will convert the signal into a continuous form.