Calculating an Ohmmeter is an interesting problem that may appear in competitions, entrance examinations as FUVEST and even tests for jobs as technicians in companies. How to calculate the resistors in series with an instrument according to the resistance and the instrument full-scale and the battery's voltage?
When we analyze the history of electronics, we usually sequence technologies with passive components, valves, transistors, and the era of integrated circuits overlooking quantum electronics. But isn't there anything missing in that sequence? That is what we will see in this article. We will travel to the past, to the time of valves, and discover that there was already a similar technology, which was somewhat forgotten, that of magnetic amplifiers.
We presented the project outlined in this article at the Evento Cultural do Colégio Mater Amabilis (Mater Amabilis School's Cultural Event) in 2012. It is also part of our book Projetos Educacionais com Energia Alternativa (https://www.newtoncbraga.com.br/index.php/biblioteca-do-instituto/7268-projetos-eletronicos-educacionais-com-energia-alternativa - in Portuguese). It can be constructed for demonstrations and elementary or secondary school-work in the disciplines of Technology or Physics.
Simple Teaching Project
Electrostatics is a subject of great importance in sciences courses, addressing an important branch of physics: Electricity. In it, phenomena related to static electricity or accumulated electricity in bodies are studied. There is no doubt that the possibility of performing practical experiments, enriching the teaching, and stimulating the students' interest contributes to learning. But, to do exciting experiments, the electroscope is an essential resource, which is precisely what we propose to build in this article.
The idea of electromagnetic weapons is not new. The so-called "Gauss Cannon" has been addressed in numerous articles and projects, but always in an experimental way, given the challenge of obtaining the necessary power. How do these weapons work? Is it possible to have this type of weapon in a practical way? That's what we'll look at in this article.
Have you ever heard that unwanted noise when turning a knob that changes the volume up and down on a stereo? As it is a mechanical component, many particles accumulate on the track of an analogue potentiometer, compromising the durability of this component and increasing the need for periodic maintenance. In a world where digital convergence increasingly transforms everything into zeros and ones, we present in this article the digital potentiometers, components that replace the analogue models with significant advantages.
This power control for the AC power line uses a Triac and an Unijunction Transistor. The control...
This excellent 3-transistor audio preamplifier is suitable for use with high-impedance...