[Grundlagen] Diode

Hello and welcome to today's capacitors there is a basic video on the topic of

diode

s Some people have already asked me if I can do some more basic videos and I will do that now. Yes, I have two themes but the ode here. On the other hand, in this case a high voltage

diode

, diodes are actually the most frequently found components in electrical engineering. They form the basis of all components and actually have a relatively simple structure. We have a driven layer on the diode itself. the anode and an n-doped layer which is the cathode and which then determines the direction of flow.

There will now be a white or silver stripe on each of the diodes. We have this in all designs, whether medium size. one, a very large one or even one of a kind that then here with the black line at that moment you can see it better because they are dependent components like poles, that is, the direction of the flow is in the direction that this line points. , so to speak, the current can flow, so we cannot flow The sword the diode then this is done as already mentioned through a transition semiconductor transition for this the silicon is doped the p-doped layers are doped with high or iridium sometimes also with gallium and the layers in the marked layers are marked with phosphorus, aluminum or similar materials.

This means that an impurity is introduced into the basic structure of silicon in the lattice structure with an external substance added to it and this then creates an excess of electrons or a lack of electrons. If we have such a diode in front of us, then everything it looks like this. Here we have the driven layer, which is in the doped layer, so it would be like this, which produces the diode. and here in the middle is the boundary area that ensures that the voltage can flow in one direction. The diode always emits a beep at the same time.

The direction and the ring can be understood as this ring, which means that depending on the diode. As always, we can directly see in which direction the current can flow and therefore it would also be important for the subsequent wiring of the entire system as a rectifier, yes, that beep. On the electrical diagram itself it looks like this or in part. It looks like an older form with a line, only it can also be found in parts, so it depends on whether the planners are American or based on European standards or based on how silicon was created Diodes This is one of those 08 15 diodes that you can buy anywhere has a voltage drop of 0 7 volts, which means that if you apply 5 volts on one side and install a diode in the circuit, then you will have a maximum of 4 on the other side. ,3 that is what happens because of this transition, which is not completely voltage free.

You can also take advantage of this if for example you still need to burn some voltage in a circuit then you can do that with diodes like. As long as you don't overload the diodes, the solar diode of course only blocks the voltage in a certain range, which means that now we can't apply an infinitely large voltage and expect this diode to maintain it. As a rule, the voltage is close. 100 140. Of course there are also higher versions that can last a few thousand volts longer and the flow voltage, as I said, I wanted 07, that means everything as a graph looks like this, we have here on one side the course that we have around of 100 volts here as a forward jumped, which means putting a voltage greater than 100 volts in the opposite direction i.e. against the diode, then this pn junction no longer works, so it is simply bypassed and then the diode is destroys and the advantage is that the defect lasts.

On the other hand, silicon diodes have a very nice curve, meaning they only pass correctly at 0.7 volts. Only thereafter do we have a significant current flow at 0.3, approximately at the beginning. that you can measure the currents there or that the transition will lead, but basically, but in general, it is a quite difficult transition and that has especially for them. The application is relatively good because then we can make a clear distinction between driving and non-germanium, which reacts a little differently, they have a slightly more advanced course, they speak earlier but they also leave early, the curve is something like that, which means that here we have 7 instead of 0 volts 0 3 vol.

There are also several ideas, for example, you can use it to convert cell phone radiation into voltage because the voltage of 0 3 volts is 0.7, which means the flag also reacts earlier. Of course, it's not that clean. For an ideal circuit, it is not that good, it has its advantages, but in reality it is. It is rarely used by microcontrollers in practice, let alone what the ode is used for other than as carbon shielding, for example, now we are going to build a completely normal circuit and we want to make sure that the user does not. destroy the circuit through bans so let's say we just want to connect my LED as a pole: here we have our LED like it has the same sound sign with the trans arrows and also a resistor in front of it so now it happens like this naturally because this LED has a very low voltage sensitivity, so someone changes the apartment and destroys the LED.

This may have happened to one or the other of you and now you can simply integrate another diode into the program with the circuit and this ensures that the voltage can only flow inwards. in the desired direction and that we have protection against burning, which means that if we simply connect 5 volts to the LED with the appropriate resistance and activate the battery then nothing happens in this case because the blocking voltage of the diode is simply enough, so which of course then we have the absolve, that is, we lose a total of 0.7 volts with a normal DCC diode, which we can then subtract previously from the resistance and make it slightly lower, the second major area of ​​application.

Of course, diodes are rectifiers, which can be a finished component like this one here with a fully finished rectifier like you could buy. They are also available in different sizes and with heatsinks without heatsinks or are also used in larger PC power supplies simply composed of. four diodes connected together in the same direction work like this, if now we have a voltage then it looks like an alternating voltage, something like this means we have positive and negative potential because the voltage they give works naturally, of course we can't use it if now On direct voltage spyware walls there is now an LED.

That means we can now build a very primitive rectifier with a diode that is supposed to come from a transformer, i.e. a transformer, it all looks like this, then we just put a diode in the circuit and then that's it. The result of this would be more positive or negative potentials on our sine curve running here and since the diode device allows the voltage to pass and is locked in direction, in this case only the positive potential is allowed to pass, which means We have a very pulsating pig, which means we only have the forward voltage style which remains afterwards in the direction of the locked circuit, of course it is not optimal because you want an ideal forward voltage, the shape looks like a straight line. which is only with a rectifier than with one or as a judge that is used.

Nowadays, people always use bridge rectifiers, these simple rectifiers, which used to be used in tube devices and when diodes were even more expensive, then things look something like this. this, then now we would have our diodes here, this time in four pieces and so we have scaled it so that we can use all the edges, that is, the full sine signal in positive, that is, in both directions, that is, who in End up with a purely positive output voltage and then do this accordingly for our three, which of course is also not ideal, meaning that additional filtering must be done here so that a true continuous voltage can be generated again. big mains input capacitors for that, but that's another part of how this circuit works, exactly how it looks in practice.

Now I'm going to show you the telescope and I'm going to turn it on now, yeah, now I have someone's frequency generator now supply us with an alternating voltage and then I'm going to show it all on the oscilloscope so I can make it clearly visible, so now, first of all, just the pure alternating voltage that looks like this, then of course you can adjust the measurement. range accordingly so you can see the full sine curve and whoever has the zero line in the middle that you can see here and so on is a little bit stronger from the black line at the top.

If we want to report everything with our diodes then the desired result is that we only have positive half waves and no more negative ones. Now I have a very simple diode here. Then I install it and now you can see how it changes and now I just hang the diode between the two mesz leads. and there is also a resistor and then I wanted to connect it to ground here. Now we just have our positive half boxes here. Now you can see here is the half wave, the full negative part is missing and then we have the next one.

Positive half here again. As I mentioned at the beginning, with a diode, the way I set it up here is no longer common because in the days of the young cosmos there is nothing like it anymore. You always use such beautiful bridge rectifiers and now you can see what it looks like so yeah, as we can see here, here is the bridge rectifier between the two built-in mesz tips, you can see it very well, but you can. look at it and see it here on the oscilloscope. Now we have the zero line here and now we will only select the positive area here, so only the positive half and therefore our AC voltage is rectified.

Of course, it still pulses, that is. , if someone is up and down this sine curve, this of course is still difficult for a similar component or DC voltage circuit, so it still needs to be smoothed out to have as straight a line as possible, but We'll get to that later in another video.