¦ Is it necessary to check the polarity of the Resistor?
Basically resistors are non-Polarized, so regardless of the polarity we can insert them into the circuit. The design of resistors is in such a way that they exhibit symmetrical electric characteristics in both the directions.
¦ What happens if I connect a capacitor in reverse polarity to the supply?
If capacitors, mostly electrolytic capacitors, are connected to AC or DC supply with wrong polarity then they may blowout or explode. The polarized field of the dielectric is maintained by correct polarity, if this is not, then the two plates act as short, and therefore, dangerous current flows and burns them.
¦ What is meant by sinking and sourcing of current particularly in turning the LED in different ways?
We can connect the LED in two modes: either sinking or sourcing mode, for switching it by a transistor. In a sourcing mode (1st diagram), the control device as a transistor sends the power to the LED, whereas in the sinking mode, the transistor receives the power from the LED. In both the modes, the transistor acts as a switching device, but the way of connecting to the power supply and to the ground is different. These two modes are differentiated based on the safety of the equipments.
V1
V2
Q1
R1
V3
V4 R2
Q3
Sinking and Sourcing
¦ How can I measure the current using a low-cost multimeter?
Multimeters are capable of measuring voltages as well as current which can be DC. AC current
measurement is not possible in low-cost multimeters, and is somewhat different from the DC, but most of the electronic components testing DC mA current are measured by connecting probes in series to such components.
For voltage measurement, we connect the probes across the components, but for current measurement, we have to remove one end of the component from the circuit and connect a red probe to that end, and a black probe to the point where the component is removed. In this way, one can know the current flowing to that component by placing the multimeter in amperes mode.
¦ How hot should be a soldering iron for a better soldering?
Anyhow, solder melts at 450 degree temperature. Therefore, it is recommended to maintain it at 650-800 degrees Fahrenheit temperature. When working with a leaded solder, it is good to use 700 degrees for surface mount parts and 750 for through whole parts. For unleaded parts, 750 degrees and 800 degrees is recommended for surface mount and through – whole parts respectively.
¦ Can we give DC to a single-phase transformer?
No, a transformer does not work on DC. For transferring of voltages from one coil to the other, induced EMF is necessary to produce the linking flux in the secondary coil according to Faradays laws of electromagnetic induction principle. As there is no induced EMF in the primary due to the constant current of DC, a large current flowing to the primary causes burning in the transformer.
¦ How the IR sensors work?
There are different types of IR sensors available in the market today, which can be varied depending on their mounting, frequency ranges, sizes, and so on.
An IR sensor consists of an IR LED and detector circuit. In some applications, these two are placed in exactly opposite direction to each other, and in some applications, they are placed side by side. In a 180 degree opposition, this IR beam obstruction detects the object, whereas in the side by side reflection of this beam, due to the object, detects the motion.
This IR beam is emitted at certain frequency typically 36-48 KHz, and mostly 38 KHz is used. This frequency of pulses sending and receiving depends on the encoder and decoder circuits used.
¦ How the Printed Circuit Boards (PCBs) are designed?
PCBs vary depending on the complexity of the circuit like single, double sided and multi layered PCBs.
They consist of conductive tracks and pads that are impressed from copper sheets and finally laminated on non-conductive substrate.
At first, these PCBs layout is prepared by using designing tools or software like CAD, Proteus, EAGLE, Board Station, CADstar, etc. And this layout is printed to copper sheets.
¦ Can we give the microcontroller output directly to drive relays, thyristors and other final control devices directly?
No, because the microcontroller output is digital, and therefore, cannot drive the analog devices like thristors. So, in between these, Opto-isolators are used to drive the thyristor with the use of the microcontroller output. These opto-isolators are also used to protect the microcontroller against the ground loops.
Similarly, in relays, coil takes a larger current compared to the microcontroller output, so there is need to use relay driver IC to drive the relay to supply appropriate current to the coil.
¦ Can we give DC to a single-phase transformer?
No, because the microcontroller output is digital, and therefore, cannot drive the analog devices like thristors. So, in between these, Opto-isolators are used to drive the thyristor with the use of the microcontroller output. These opto-isolators are also used to protect the microcontroller against the ground loops.
Similarly, in relays, coil takes a larger current compared to the microcontroller output, so there is need to use relay driver IC to drive the relay to supply appropriate current to the coil.
¦ Why I have to use motor driver IC to drive the motors like DC and stepper motors?
As we have discussed above, the microcontroller output is a control signal that ranges in between a small or low current, and therefore, can’t drive the motor directly and needs a driver IC. Not only for the motor, but also for a bunch of LEDs, we need multiplexer IC; for speaker we need audio amplifier IC, and for larger loads we need a relay driver. And also, certain applications require different rotations of motor as in the case of a robot, it needs left, right, forward and backward movements. In this case, an H-bridge motor driver IC is needed to drive the motor in all directions.
¦ How to choose a microcontroller against some advanced controllers like PIC, Arduino, Raspberry Pi, etc.?
Nowadays many microcontrollers are available for a simple circuit design to reduce extra hardware systems. Simple 8051 microcontrollers are the basic controller, and are the best option to get the root knowledge on microcontrollers. A few other microcontrollers like PIC, ARM, Arduino, etc. come with additional inbuilt features. This differentiation also depends on several other factors like the number of bits, instruction set, ADC, timers and counters, etc.
¦ What are the steps to keep in mind before programming a microcontroller?
The following steps must be kept in mind before programming a microcontroller:
o Program must be logical and not too lengthy so that the memory can be conserved.
o It should be simple and easily understandable.
o Ports of the microcontroller must be selected for efficient usage of pins.
o Programming through C is the best option for the beginners because C is user friendly and flexible as it doesn’t require an in-depth knowledge of registers compared to the other assembly level languages.
¦ For a certain low-cost application which controller is the best option, for instance, whether the 555 timer or the 8051 microcontroller?
To use a 555 timer, we need extra hardware components, whereas if we use a microcontroller only programming concept does the job. Moreover, a microcontroller is more reliable and less complexity is involved with the microcontroller.
Testimonials about Edgefxkits.com
Lingaraj Hiremath
P S Kiran
Sumanthch
1. Using TV Remote as a Cordless Mouse for the Computer
I saw one of the project in your website and purchased the project from you and I like your service and guidance very much. I like my project very much and the components which you have given me very clearly. Finally Edgefx people are giving a good projects and support to the engineering students.
2. Density Based Traffic Signal with Remote Override in Emergency
I have searched in Google and came to know about your website and seen the past reviews. I felt that your service and products is good. Then I got confidence to purchase the project from Edgefx technology. The quality of the project and service provided by Edgefx is very good. I am satisfied.
3. Speed Checker to Detect Rash Driving on Highways
I bought from you because i was convinced that you are one of the top leading sites in delivering good products.
The benefit is that it was delivered fast and it was in good working condition. Please check the program used for microcontroller before sending and also send videos of making that particular project not a random video of making of general project (such as soldering etc). Students get benefit mostly. I am also a student. This project helped me in my academics. Yah i didn't expect that you send a readymade kit in DIY kit also which was a very good idea.
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Website is really cool with all the details of the projects available. We wanted a project that is close to our instrumentation domain with sensor and automation. We had no doubts at all, we are confident about the output.
We heard through word of mouth and came to know it is really good. Perfect soldering good to look at, neatly fabricated and loved the way that kit is packed with tutorial cd , abstract , etc. Perfect, keep going and come up with many more innovative projects and implementing new ideas.
5. Site feedback
The website is well established and everything is clear about the projects and their cost. I was initially concerned about the trainer, PCB design. I purchased the project kits as I observed that this concept is very trustful to the students as well as faculty members for knowledge based and industry exposure. Good concept of making the project. I will be extremely happy if the project is performed and run also on the zero voltage PCB.
7. Contactless Liquid Level Controller
I had a question whether the kit will work properly or not. If some problem is there then who will solve it or will anybody respond to it. I was having the feeling that you are having a wider range and may be i will get after sales service also. Good material nicely packed. Some problems i faced but i always got the proper response whenever i contacted to Edgefx.
8. Long Range FM Transmitter with Audio Modulation
I purchased Edgefx kit with your dealer JauhariInfotech-Allahabad because your products are fully tested and timely deliverable. Your service is awesome everything as properly working there is no problem with the elements which are used.
You can improve your future delivery by reducing its cost and by purchasing better phone help line services.
R.SharadaPriyadarshini
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9. Sun Tracking Solar Panel
Yes, I saw the website it was fine, very easy to use and user friendly even. I had question that it should be more complex and different from others. I decided to buy a kit from Edgefx, because by seeing the projects in the site. I bought DIY kit and i liked it. Provide higher end projects.
10. Detecting Power Grid Synchronization Failure on Sensing Frequency or Voltage Beyond
My main concern was within stipulated we will get output or not. But I am happy as other vendors do not provide proper design, so output is a major problem. Got clear details in the CD/DVD.
11. UPFC Related Display of Lag and Lead Power Factor
I selected this project based on output video and abstract/ output related queries. I was not clear before purchase about Micro controller coding/ commends. But I am happy now. Output video is so clear to get information. PCB layout is so nice.
12. Railway Track Security by GSM with User Programmable Number Features
Output video enables even a layman also to decide the kit / kit type are good. I liked the different kit types and all the material needed for project we got in kit itself. Working good / easily able understand. Everything about the kit is good.
Abhishek Mishra
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Vishal Kale
13. Wireless Power Transfer
Edgefx kits are awesome. They are trustable as they say. Their ideas are just amazing. This project helped me a lot. It was amazing project was delivered on time thanks to Fedex. Edgefx support team is also very nice. Thanks to even sadiq who helped me a lot. The kit was well organized properly working no hardware failure full report full access. Overall project was awesome. It’s 10 out of 10.
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I had the question Will the project work accordingly? I called the office of Edgefx, got very good guidance & I am very satisfied with the response. 100% output was guaranteed online, so I found edgefx to be a lot trust worthy &
did not think of anything else. Amazing support from your team. Pleasant response no calls were unattended, Hats-off to your team. Presently you have system that works and is totally sufficient for my exploits and sincere, thank you!
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The process of doing project is straight forward and clear so it took minimum time for us. We got complete notes, material and components related to project. We recommend Edgefx kits for all those who want to manage things by themselves.
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Conclusion
About the Edgefx Team
The credit for each and every bit of information added to this eBook goes to the team of Edgefx technical writers and authors. The team of Edgefx, has been relentlessly working to ensure that the researched and practically implemented and pragmatically proven written work of this eBook must serve the purpose of its readers. With the unmatched technical expertise and pioneering works in the field of electronics, electrical and robotic engineering Edgefx Kits and solutions is providing technical solutions and project kits to millions of engineering students around the globe, since 1997. The credit for the projects and the circuits goes to the technical team of the Edgefx.
Right to readers
This book is intended to give practical knowledge on building the electronic projects in the simplest way possible with the practical circuit examples. Any person interested and looking forward to have this book can enjoy the privilege and authority to download, reprint and distribute this book. However, no person is entitled to make any modifications or alternations to the book and to use it for his or her own monetary profits.
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The content, information, concepts, technical inputs, and other such data is the sole property of the Edgefx Technologies and the team involved in research and writing. Therefore, the technical content including the images is solely authorized as the copyrighted material of the Edgefx technologies. The information written in each and every chapter is written based on relevant research and inputs by the team of authors. The projects and circuits mentioned in this book are the properties of Edgefx team and are fully tested and authenticated.