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Introduction
Do you know buffer amplifier or isolation amplifier? As we all known, the op amp is a component that amplifies the weak signal, which can be made into different forms according to the circuit requirements, and the voltage follower is one of them. The output signal is exactly the same as the input signal, here voltage divider is used to isolate the signal and enhance load capacity.
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1 Voltage Follower OP Amplifier
The op amp follower sacrifices the voltage amplification factor in exchange for the performance of increasing the input impedance and reducing the output impedance. Because the gain of the op amp is extremely high, the input impedance of the op amp follower tends to be infinite, and the output impedance tends to zero. Within the rated output current range, the feedback voltage is equal to the output voltage, the output voltage is in phase with the input voltage, and the output voltage is slightly smaller than the input voltage. It should be noted that voltage follower is a special case of negative feedback amplifier (voltage series).
Op amp voltage follower is actually a simple circuit structure which play a role in impedance matching. When a weaker signal is used to drive a relatively high current, voltage follower is often added in the middle, so that it can make weak signal stronger. It improves the load capacity to a considerable extent, while ensuring that the waveform and amplitude of the signal remain unchanged.
For example, a single-chip microcomputer outputs a PWM signal to control LED lights. One LED does not require much current, so there is generally no big problem, however, when multiple LEDs need to light, current may definitely not large enough. If the current output is not enough, which may affect the signal output by the single-chip microcomputer, in this way, the voltage follower comes in handy.
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2 Voltage Follower Characteristics
2.1 Op Amp Impedance Matching

When the op amp gain is approximately 1, that is, the magnification is approximately 1. The "follow" in the follower means that the voltage remains unchanged before and after, and the output waveform is almost not lost. It can be composed of transistors or operational amplifiers (best). Because the op amp input impedance is large and the output impedance is small, voltage follower can reduce the impact on the signal and improve the load capacity.

2.2 Buffer Amplifier & Isolation Amplifier
Here is a question, how to understand the buffering effect? Is the voltage of the former having a small impact on the back circuit? No, it is equivalent to a constant voltage source. Within the design requirement, no matter how the circuit connected to the subsequent stage changes, the output voltage is constant and does not change. In this way, the magnification or other performance of the previous stage can be kept unchanged. Otherwise, if the previous-stage input impedance is large, and the latter stage is small, the signal will definitely be distorted. For example, if a sinusoidal voltage waveform with a peak value of 10V, the sinusoidal peak value loaded to the latter stage may only be 8V. After adding a voltage follower, the waveform loaded on the input of the voltage follower will basically not change, and the input-output stage voltage ratio is very close to unity. So there will be no distortion.
Since the output impedance of the voltage amplifier is generally relatively high, usually in the range of several kiloohms to tens of kiloohms. If the input impedance of the subsequent stage is relatively small, part of the signal will be lost in the output resistance of the previous stage. At this time, a voltage follower is needed to buffer from it. Another advantage of applying a voltage follower is that the op amp input impedance is increased, so that the capacity of the input capacitance can be greatly reduced, which provides a prerequisite guarantee for the application of high-quality capacitors.
Another question, what about isolation? Because the op amp input impedance of the voltage follower is very large, it can be approximated as an open circuit. Of course, this open circuit is for the previous circuit. In this case, the previous circuit will not affect the subsequent circuit. However, "open circuit" means what, is it really open? No, the previous voltage is transmitted, but the corresponding current is not transmitted. This is the isolation effect.
For example, if the MCU outputs a PWM waveform, you want to use it to control the brightness of a small light bulb. However, the output capacity of the IO port of the general MCU is limited. You can directly use the PWM output from the IO port to drive one light bulb. More than one doesn't work. In this case, you can add a voltage follower, so that the voltage is still the original voltage, but the driving ability has improved. Of course, the output capacity is not increased out of thin air, but comes from the input power of the op amp. In electronics, the diode has current amplification capability, and its source of amplification capability also comes from the power supply.
In Hi-Fi circuits, the controversy about negative feedback has been around for a long time. In fact, if there is no negative feedback, most amplifying circuits will not work well. However, due to the introduction of a large loop negative feedback circuit, the back EMF of the speaker will pass through the feedback circuit and be superimposed with the input signal. The sound quality is blurred and the clarity is reduced. Therefore, some of the final stages of the power amplifier adopt a circuit without large loop negative feedback, trying to eliminate the disadvantages by disconnecting the negative feedback loop. However, since the operating current of the final stage of the amplifier varies greatly, its distortion is difficult to control. Here, the function of the voltage follower is just for the application. Putting the circuit between the front stage and the power amplifier can cut off the interference effect of the back electromotive force of the speaker on the front stage, so that the clarity of the sound quality is greatly improved.

3 Op Amp Follower Circuit Analysis
3.1 Op Amp Voltage and Load

The output and the inverting input terminal are connected in series with a 10k resistor to ensure excellent characteristics. An ac signal is input at the non-inverting input terminal. Of course, dc and ac are all okay, so you will get a very high voltage at the output terminal. AC voltage that is similar and has excellent load capacity, with buffering and isolation effects.

3.2 Op Amp Voltage Follower Stability
The problem of using a voltage follower to keep the operational amplifier stable, that is, how to reduce the oscillation in the amplifier circuit using negative feedback to maintain stability, there is still no final conclusion. The ideal operating state of the op amp is that the output voltage and the input voltage are in phase, that is, when the applied voltage at the negative input causes the output to increase, the op amp can reduce the increased voltage accordingly. However, there is always a difference in phase between the input and output in reality. When the phase difference between the output and the output is 180°, the negative input and the positive input are exactly the same, but the output that should have been reduced is enhanced. It becomes a state of positive and negative collapse. If it falls into this state in a specific frequency band and still maintains the original amplitude, then the output frequency and oscillation state will continue.

3.3 Op Amp Phase Difference Problem
The main reason for the phase difference between the input and the output:
1) Due to the inherent characteristics of op amps.
2) Due to the characteristics of the other feedback loop in circuit.
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Fig a and Fig b respectively represent the voltage gain-frequency characteristic and phase-frequency characteristic of the operational amplifier. As shown in the figure, the voltage gain and phase vary with frequency. The difference between the op amp gain and the gain after feedback (0dB when using a voltage follower) is the gain (feedback gain) of the feedback loop. If the feedback gain is less than 1 time (0dB), then, the phase changes by 180° and returns to the positive feedback state, the negative gain will gradually attenuate in the circuit and theoretically will not cause oscillation.
On the contrary, when the phase changes by 180°, if the loop gain corresponding to the frequency is 1 time, the original amplitude will be maintained. If the loop gain corresponding to the frequency is greater than 1, the amplitude will gradually diverge. In most cases, in the process of amplitude divergence, the amplitude is limited due to the influence of nonlinear elements such as the maximum output voltage, and the oscillation state will be maintained.
Therefore, the difference between the phase corresponding to the frequency when the loop gain is 0dB, 180° is an important factor for judging the stability of the negative feedback loop, and this parameter is called the phase margin. Unless otherwise specified, when a single amplifier is used as a voltage follower, sufficient phase margin must be maintained (Fig b.).

4 Op Amp Voltage Follower Application
In many typical circuit designs, there will be an op amp follower before the AD converter. Whether this follower is necessary or not depends on the requirements of the circuit based on the understanding of the function of the follower. First analyze the role of the voltage follower here:
The function of the voltage follower here is impedance transformation.
Impact 1: The input impedance becomes very high, so that the impact on the input signal can be small.
Impact 2: The output impedance becomes very low, and the impact of AD input impedance on the input signal can be very small.
It can be seen that the follower is very meaningful. Secondly, analyze your own circuit and the signal under test to make a decision whether to use a follower. Here are some rules to confirm:
1) If the output impedance of the signal is very small, then the Impact 1 can be ignored.
2) If the input impedance of AD converter is very large, then two impacts can be ignored.
3) If both impacts can be ignored, no voltage follower is necessary.
4) If there is an impact, a voltage follower is needed.
Andrewen 3 july 2021, 2:07

When you think of any occasion or festival, you think of the décor and the appeal of it. Flowers are a no brainer when it comes to planning for special occasions.


They bring life to the occasion. To see the fresh flowers in beautiful colours brings a big curve on our faces. They set the mood for every occasion and choosing the right flowers from florists in Calgary Alberta is quite an art.


It is a skill only few can master as there is so much variety to choose from that you are bound to feel overwhelmed by it. There are no hard and fast rules to buying flowers but you should keep the following points in mind:


• Keep The Person and Occasion in Mind: It is easy to get swayed by the variety at the florist shop and buy something that you didn’t intend to. Flowers are a way to show your affection, so buy something that is dear to that person, maybe switch roses for vivid lilies and orchids.


• Freshness: The last thing you want is to wake up to a dead bouquet of flowers. Make sure you buy fresh flowers that at least for 2-3 days and bring sweet aroma in your life.


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flowergallery 2 july 2021, 12:22

Having a place of our own is one of the initial things we dream of after earning. We all want a place, which we can call home and feel like home. It requires a lot of effort to make a place home, where we can relieve our stress and feel the warmth. We all want our homes to look beautiful, organized, and eye-soothing. Firstly, an organized house means to have every piece of furniture and objects in their correct spots. If your furniture Calgary is well-organized and everything is in its spot, then your home would look eye-soothing.


Apart from organizing furniture, what makes a place with a good interior is contrasted furniture. The furniture must complement the color and style of your home. Once you find the required pieces of furniture, then you need to add some items that add glitter to the place. For example, adding paintings, crafts, artefacts, etc., to the living area. You can also add lamps, chandeliers, hanging lights, etc., to make your place brighter.


Adding all such things helps you to make a place look like home. But if you still find it difficult, then you could take someone's assistance regarding organizing the interior of your house with the right items of furniture, and so on. For assistance, you could easily look up ideas on the internet. Else, if you seek personalized assistance, especially for your place, then you can ask experts like interior designers or furniture designers who have a wider vision in this area. With the consultancy and introduction of ideas from the experts, you can make your place look amazing and unique. Now, the question is where to look for assistance regarding choosing the right pieces of furniture, lightings, and other useful items.


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Interiorliving 2 july 2021, 10:51

Mixing up modern and vintage designs is something that sounds very exciting but sadly it isn’t everyone’s forte. Not everyone has the eye to pick the regal vintage pieces that compliment their Calgary modern furniture.


But if you are interested in some mixing and matching and are confused on how to do it, these tips would help you get started.


• Start with the Proportions: Think about the end result, and the feel of the place you desire. If you see yourself in more vintage-style room then add more vintage accents and keep the rest of the décor minimal. But if you prefer the modern mid-century furniture more, then add maybe one or two vintage accents. It could be a vintage mirror or maybe some velvet cushions and covers. Instead of making a messy concoction, let your designs stand out.


• You can Change Things Throughout: If your room has a modern style of furniture and you like the functionality it provides you then you can keep that intact and maybe switch things up in the lobby, by adding more vintage styles. You can go for metallic gold vases and lamps or velvet sofas. In this way, you can mix and match in your whole house instead of just one room. A good rule of thumb is 80% of one design and 20% of the other.


• Bring in the Colours: You don’t need to add accents of the other style. You can switch things up in your Calgary furniture modern by introducing a vintage colour scheme of rich colours like emerald green or blue, ruby red, purple or maybe rose gold.


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Interiorliving 2 july 2021, 10:50

Planning to book a glam boudoir photoshoot? Read this!


The feeling of nervousness and excitement is quite common before a boudoir photo shoot. So, if you are feeling any of these things, that’s not an issue.


If you want to make your boudoir photography a success, you just follow the tips that are mentioned below. These tips will prepare you to get ready for the shoot.


• Make sure you find a professional photographer: No matter how great your outfit is or how stunning you look if the photographer is not professional, your photos won’t come as expected. So, make sure that you choose a professional photographer who knows how to complete the work.


• Check photographer’s website and work: If you want to know whether the photographer you are hiring for the work deserves it or not, check out their website. When you do this, you get an idea of how the photographer works and also, whether you want that kind of work or not.


• Don’t get stuck in inspirational images: Another thing that you must remember during a boudoir photoshoot is that you should not get stuck to inspirational images. Rather, you should go with the flow.


• Do not spray tan: Spraying tan might seem like a good idea but actually, it is not. You must let everything look natural so that your boudoir photos can look better than before.


• Make sure you are groomed: Another thing that you must remember is grooming yourself at all the right places.


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There are so many things that we do daily and don't even give a second thought to how important and a necessity it is. Take eating, for example, we do not even give a second thought about the fact that we can eat smoothly without any pain. It is when we have a severe toothache and can't eat a bite without pain, that we realize the importance and the necessity of eating.


Are you someone who is also suffering from severe toothache? If yes, then you should immediately visit specialist endodontics Lethbridge. You take care of your health but do not consider oral health a part of it. Even when your body is trying to give you the signs that something is not alright, you do not even acknowledge them. That is why later on, you have to face such severe pain. Here are some signs that you should not ignore and visit a dentist:


1. Swelling: The first sign that you might notice is that your mouth gets a little swollen. This can be because of getting hurt or any internal problems. But either way, visiting a dentist is a must.


2. Pain while eating or drinking: When you sense even the slightest pain in your gums while eating or drinking, that means something is not right.


3. Redness around your mouth: This does not happen very often, but if you notice a redness around your mouth, it the time to visit a dentist.


These are just a few of the many signs that you might ignore. Now, as important it is to visit a dentist, visiting a trusted and reputed dentist is equally important. If you don’t know a trusted dental clinic then you can approach Land O’ Lakes Dental for the job.


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landolakesdental 2 july 2021, 5:35

Are you thinking of visiting a dentist? Are you confused about how to choose the right dentist? If your answer is yes then you are at the right place. Choosing the right dentist can be quite confusing. Nowadays all the dental clinics claim to be the best but you have to choose the right one where you can find an experienced dentist Lethbridge.


But how would you find the right dentist? It can be a time-taking process. There is no need to worry because we are here to help you. We have listed down the top 5 qualities that you should look for in your dentist:-


1. The number one quality is that your dentist must be an amazing communicator. This is because only then they would be able to inform you efficiently about what the problems are in your oral health and what kind of treatment would be required for it.


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landolakesdental 2 july 2021, 5:33

You invest a lot to own something, whether it is your residence, your vehicle, your business, or your health. After a lot of hard work and commitment, you get all these things. But since life is full of uncertainties, you do not know what could come next. If you have a car, you could get involved in an accident. This uncertainty can cost you so much. Therefore, to bear the situations like these, the concept of insurance came into existence. Insurance policies ensure that after an uncertainty, your financial loss can get covered, at least.


Kirkham Insurance is an insurance company that has an association with several insurance companies that could provide you the financial cover in case of any loss. Kirkham Insurance provides you with the car insurance Lethbridge. The company performs the job of making a list of insurance policies that can cover your car and other automobiles and minimize the job for you. In this way, you can cover the uncertainty related to your car and automobiles. Kirkham Insurance performs this job to make sure, in case of any damage you do not have to face difficulties.


Kirkham Insurance understands that your house is your biggest financial investment. If anything worse happens to your biggest financial investment. Then you might need insurance to cover the loss. Kirkham Insurance lines up the most optimal home insurance Lethbridge policies. These home insurance policies could provide you the best cover for your damage. Kirkham Insurance ensures that at the time of claim, you do not have to face so many documentation procedures and any kind of delay, as they understand to not bother you during the time of crisis.


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kirkhaminsurance 1 july 2021, 13:21

Life is full of uncertainties and it comes knocking at the door when you least expect them. We work so hard in our life to buy that house, that car, but what we don’t realise it, that they might get damaged one day. And if that happens, you will be left with nothing and all your hard-earned money will go down the drain.


That is why it is suggested to get a life insurance Lethbridge policy from a trusted company. Before you get stressed out about not knowing a trusted insurance company, we need to tell you that we know one company that can be of great help to you. Can’t wait to know about this company? Don’t worry we will not keep you waiting and tell you all about this company.


Kirkham Insurance is a trusted and well-known company that will help you in finding the right insurance company. They are in this business of helping people find the right insurance company for quite some time now. They have a Team of professionals who are not just skilled and experienced but also have expertise in this field of work.


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They make sure that they find an insurance company that is not only trusted and reputed but also offers plans according to your requirement. They also ensure that they find an insurance company and a policy that is within your budget. With the help of Kirkham Insurance, you can compare home insurance companies before choosing one. They provide complete details of all the best insurance plans and companies, for you to choose the one that best suits your requirements.


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kirkhaminsurance 1 july 2021, 13:20

In 1706, the first modern life insurance company was founded in London. It was called The Amicable Society for Perpetual Assurance. What a phrase that is ‘perpetual assurance.’ An underlying dilemma for us humans is that we crave for this perpetual assurance, but nothing in this world is certain or even perpetual. But there is however, life insurance and car insurance Lethbridge.


Most car insurances as mentioned above do not provide 100% assured coverage for the damages. They may share the cost of the insurance claim with the insured driver by handing over a deductible. A deductible is an amount that the insurance holder agrees to pay towards the cost of their claim. You must choose a suitable and optimal amount for your deductible.


Remember this is a fixed premium that you have to pay, so make sure that your pocket allows it comfortably. It you can easily pay $1500 deductible as opposed to $5000 deductible, then go for the $1500 option.


A high deductible charge, lowers the amount you have to pay as premium for your insurance bill. This is because you take away a major part of cost risk from the insurer in your own hands. But in the long run, a slightly higher premium is more pocket-friendly than a high deductible charge.


If you’re deductible amount surpasses the amount of damage, then your insurer would not pay for any damages. If you’re deductible is $1500 and the damages cost $700 dollars then you would pay for the whole amount yourself.


You can update your deductible during the policy term or while renewing your auto insurance Lethbridge. Reviewing your current damage deductibles, can tell you whether you need to increase or decrease your coverage claim.


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kirkhaminsurance 1 july 2021, 13:19