I usually get emails from electronics beginners with the following questions:
- Does this particular project work with 9V even if the schematic says 6V?
- Should we be very strict with resistor, capacitor ratings?
- The project works on breadboard, but does not work on PCB, why?
- I have a project that uses 47k, can I use a nearest value resistor?
Let me share some of my experiences that I have gained from a wide span of exhibitions, teaching and product development work. If you follow my tips, I am sure that you will save much time while building your projects and they will definitely work.
a. Know the fundamental formula or logic behind the circuit.
I have seen people who just start projects without knowing the fundamental logic or working principle of components. For example, if you are using an LDR, know that its resistance changes with light intensity, if you are using a 555 timer, know that there should be three important working modes, astable, monostable and bistable. You will fail in any project if you don’t know the fundamental working principle. Beginners don’t need to understand all the inner and advanced physics behind components, just find the main principle. If you know the principle, you will know the importance of component ratings/specifications.
b. Work in modules.
If you are making a big project, remember that your project is a combination of small projects. Therefore, break your big project into small modules, make them work and finally combine all. For example, I have given some examples, clap switch with 3 different modules, infrared based music transmitter and receiver and object counter. In the clap switch circuit, I have made 3 different modules on small breadboards and combined them. Therefore, split the circuit and work on it. Get more ideas from MINIBREAD.
c. Never start electronics with big projects. Start with an interesting dark sensor.
Well, this is a psychological thing. Electronics amateurs enjoy a dark sensor or infrared switch or a clap switch rather than a voltage regulator. I know that voltage regulator is quite a boring project. Making an automatic dark sensor would collect some of your friends also to see that small but still an amazing circuit. I feel that making a dark sensor inspires you because that works in your first attempt. You can quickly show to your friends and family members and I am sure they will encourage you for working on such a wonderful project. You can WATCH THE VIDEO of a simple dark sensor on this link, I have shown all the steps. SEE OTHER PROJECTS THAT WORK IN YOUR FIRST ATTEMPT.
d. Make a list of different components and find their working principles.
You project might have an electret microphone, a resistor, a thermistor, an optocoupler, a diode, etc. …just make a list of all the components and find their working principles on the Internet. It’s really important to know the pin configuration of the components you are using. And listing your components would also help you to find bugs in your projects.
e. Take nearest values for components.
If you are making a project for yourself or for school exhibition, you can put resistors of close values in ANY kind of projects you are doing, except for Radio/FM projects. For example, you might have seen some projects using 220Ohm, 330Ohm, 470 Ohm current limiting resistors for LEDs. It doesn’t matter if you put 220, 330 or 470, the circuit works for all, but it might not be 100% accurate. During your learning phase, you can ignore accuracy. I even use 1k, who is coming to check :D. ? Besides, if a project works with 6V, it also works for 9V. However, in some cases, you need exact voltage ratings, but I am sure that the author mentions it on his project. Having said that, do remember that all the projects published on the Internet or books are supposed to work perfectly with the used components. But, beginners can ignore that. There are several theories like biasing, voltage divider rule, etc. to understand the complete operation of a project. And you need to enroll in a semiconductor class or engineering course to understand everything. If you are just an amateur or a school student, USE THE CLOSEST VALUES OF RESISTORS, CAPACITORS and POWER SUPPLY. However, I repeat, you should understand the fundamental working principle of a project.
f. Make your project on breadboard, before you fix it on PCB.
If you have just started electronics, make your project on breadboard before you jump on to PCB. The advantage of using a breadboard is that you can modify the project if you are not happy with the output. SEE HERE- HOW TO USE A BREADBOARD?
g. Do not work with 220V if you are not confident.
I get several mails about using 220V bulbs and other appliances with circuits and I am tired asking his/age and profession. I really don’t teach how to work with 220V. If you are not so confident about using a relay or a triac, don’t put your hands on it, your project can hurt yourself and possibly you will keep electronics away for the rest of your life. Therefore, get some experience before you choose 220V.
If you are confident enough to work with 220V, here is the link for using a relay: http://www.buildcircuit.com/how-to-use-a-relay/
h. Keep a pack of essential/mostly used components.
Beginners or professionals need a set of components they often use, for example, resistors, capacitors, transistors, etc. You should at least have a pack of resistors/capacitors so that you can test your project with the closest values resistors/capacitors if you don’t have the required one.
i. Use short wires
I have seen beginners using long wires while building their projects, it is wrong. There are many disadvantages of using long wires, for example, if you ask your teacher or friend to debug it, he will be confused about the connections; your circuit looks bad; you cannot pack it in a box; long wires induces extra inductance in the circuit and that may change behavior of your project…and there are still many reasons, therefore, use short wires. One example is given below:
If you look at this project, you can see all the connections clearly.
j. Capacitor ratings
Most of the projects available on the Internet just show capacitance values of capacitor and not the voltage.If you have such project, use a capacitor with voltage rating 16V or 25V. The point is, if you are using 9V in your project, the capacitor voltage rating should be greater than 9V. If you are using 6V power supply, then 10V, 16V, 25V rated capacitor works well.
There are still many points to notice, but this time I can write only these, I will continue this chapter some other days, keep on visiting buildcircuit.com.
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