In this lesson, we're going to draw a simple circuit which is a amplifier or if a people that resistor and we're going to do a C analysis of it. So, first thing we're going to do is click New schematic and draw these circuits. It's going to use some resistors. And these one ask some capacitors Kanto air. Contour air again another, another here. Let's put it john higher position on inductor ASCII and we must use a VPN resistor so you got to look for one NPN Okay.

Now we see that we should move some some, some components in order to make it neat. So it's better now we can move the resistor here, capacitor, all free and then we're going to connect all the components ask let's zoom out Then, but ground voltage source lover grounds connects And then we're going to set the values. This is going to be 470 ohms 470 ohms, which is also a commercial value you can find components on the shelf of these value. These one are going to choose 680. Then microphones for this capacitor let's move these labeled here so we can see it's better. This capacitor, micro and then this poor guy just sat top does Voltage through 12 volts okay and then click here and so we can set up these components Let's choose transit to true nano nano ferrets and regards to choose your honden Trent 20 micro a but with that output label here and then this voltage is this signal input voltage source so we're glad you're here chose a Siva Lu because We're going to do a AC analysis, which as we have done in the previous example, we put a range of different frequencies into the input of the circuit and we get all the results, and lots, all this compile the results in a single plot, showing magnitudes and phase.

So that's what to what we're going to do. So let's choose resistor. Let choose B two. b c 547 b, I think this is Roger. And then we're going to simulate a did simulation comment. ac analysis chose decades.

Number of points 1000. Remember, this is a synchronized amplifier. So, this amplifier is going to have an emphasis on the frequency defined by these LCC records LC donk secret. So, there is one value or frequency he reached the amplification is much, much greater than the rest of, of their range of frequencies. In fact, in other frequencies, family amplifier may even attenuate all these frequencies. So, we're going to put a really small frequency and very big for us See, to our standards to try to find what these resonant frequency is.

So click OK. And then we are going to click the Run command and click V out. So, we get here, the magnitude magnitude plot and the phase plot. And we see we can identify here, very resonant frequency. We can double click here, select these. But we're going to see the frequency right in this corner. So, but it's here and look at this.

Left bottom, it is 72 dot 275 kilohertz and at this point amplification is 67 dot 8869 decibels. So it's a very high amplification and then we can click zoom to fit. So, we return to Our previous visualization. So, we can see here what I said before, in frequency is much smaller or much larger than the resonant frequency. The amplifier secrets in fact, attenuates signals of these frequencies. So the focus of this secret is on They're very tiny, for very tiny frequency range shown here.

Effect. What is the bandwidth of these amplifier, we see that here we have 6067 dots 71 approximately, then we're about to find free the free decibels below which is 64 dot 7164 64 dot a six five dot seven are glad to take and dx shown in the bottom left which is 744 hats It's not a very big Frick, big bandwidth. We can return to zoom to fit and see what happens if we change this relationship. This frequency, the value of this frequency is entirely defined by the product, inductor capacitor. So if we multiply one of these values by, say 10 and divide the order one by 10. We're not going to change the frequency of other but that lot isn't the same.

So let's see what happens. Let's increase these value, not tenfold increase. Okay? Let's decrease it by tenfold. Then we get here and we see higher bandwidth effect. The peak is at 77 seven pardon me, the peak is at 67 seven decibel.

So we're going to look for 64 dot seven, which is 664 6464 dot seven. We can see that the x which his or her bandwidth is seven got free 99 kilohertz, so it's almost approximately 10 times increase on the bandwidth. So, all these things you can know which effect they have on the performance of the secrets, you can change it and has simulated, what change in bandwidth, the frequency of the amplification, and so on. You can see all of these things and then we can also see how the secret behaves. If we change the transistor Sorry, go to pick new transistor as we have gone and change for instance two, two and 2222. Click OK. And then it changed the attenuation automation, not amplification a little bit, but is that a the same same behavior and we can change these four is one and see again it's almost imperceptible.

So, you can do all these changes, you can change the biasing resistors to see what happens these capacitor and see what is the effect of the changes and see what happens on the circuit. So it was our AC analysis lesson using a amplifier for They be JT which is a people at transistor this one and BNP Potosi store. So see you next lesson