Recent content by mitocondrio

So... My transistor does the switching job when I put my finger on its base. I know that NPN transistor are activated with positive charge, so... What happens between transistor, my finger and the earth? What happens to the charge? I don't know much about this, I would like an introduction...

Yep but I'm talking about the fact that the coil is a simple wire. And if we connect a simple wire to the terminals of the battery it should be a short circuit and heat everything :(

How can you have a simple coil connected to a battery without having a short circuit in it? How do they make electromagnets that don't heat the battery? Thanks :)

I don;t have an osciloscope, I would like to know how to build a circuit that can generate the signal. Could you help me? Thank you :)

I'm studying RFIDs and how they work. I would try to do an RFID emulator just to learn better how things work. It's nothing under the government specifications, I will just use this to emulate an RFID tag for like 10 centimeters away form the reader. The tags I want to emulate uses the 13.56Mhz...

I want to do some RFID emulation, but I would like to learn how to create this frequency. I already learned the modulation part. I want to learn by parts. I will thank you so much if you can help me!

Let's say I want to create an eletromagnetic field with a 13.56Mhz frequency... How do I proceed it with a circuit? I don't need a large explanation, but please tell me how do I learn about it. Thanks :)

Well, passive RFID tags has to be inducted to work. When the induction reaches the tag, it powers itself and then the microcontroler sends a RF signal to the reader, with the product ID, rigth? What I want to know is: what type of induction does it use? How the induction radio frequency...