The feedback signal in circuit theory
In circuit theory, the feedback signal was a signal that was taken out of part or all of the output signal of the basic amplifier and then sent back to the input of the amplifier through a certain method. When the feedback signal is mixed with the input signal, it will form a new net input signal, which will affect the input and output characteristics of the circuit. According to its effect on the net input signal, feedback can be divided into positive feedback and negative feedback. Positive feedback would increase the net input of the amplifier circuit, which might cause the circuit to be overly excited, causing oscillation or distortion, but it had special uses in certain situations (such as making electronic instruments). Negative feedback reduced the net input of the amplifier circuit, which could correct the deviation of the output like a strict coach, so that the circuit remained stable and linear. It was widely used in electronic products (such as smart phones, precision medical equipment, etc.). Negative feedback can also be divided into voltage feedback, current feedback, or a mixture of the two according to the different sample methods. The voltage feedback could adjust the gain of the amplifier by controlling the size of the feedback resistance, and the current feedback could improve the response speed of the circuit in high-speed operation and high-frequency amplifier. In terms of circuit components, a feedback circuit usually consists of a feedback network, an amplifier, and a feedback source. The feedback coefficient is the ratio of the feedback signal to the output signal. The closed-loop gain (the actual gain after considering the feedback) can be calculated by the open-loop gain (the gain without feedback) and the feedback coefficient. Read more exciting novels for free
The components of the feedback circuit are
The components that make up the feedback circuit are different for different types of feedback circuits and application scenarios. For example, in a voltage stabilizing feedback circuit, common components include a sensing resistance, TL431, an optical couplet, etc. In some circuits, a feedback circuit may be formed by components such as a resistance, a voltage amplifier, and a voltage amplifier. For example, from the output point to the negative input of the differential amplifier, there is a resistance connected in parallel with two resistances, and from the negative input to d, there is a resistance and a voltage amplifier. In addition, in the feedback circuit, the operational amplifier was the core component, and it formed a circuit to guide the feedback signal with external components such as a resistance or a amplifier. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is the feedback amplifier circuit a closed loop circuit?
In an amplifier circuit, a circuit with feedback was called a closed-loop circuit. The feedback amplifier circuit had a feedback path from the output to the input. This feedback circuit was in a closed-loop state, so the feedback amplifier circuit was a closed-loop circuit. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Important indicators of feedback circuit
The feedback circuit has the following important indicators: 1. ** Phase margin **: It is an important indicator to measure the stability of a circuit. It represents the phase difference between the input signal and the output signal when the gain of the circuit is 1. When the phase margin is greater than 45 degrees, the circuit is considered stable. Negative feedback can increase the phase margin and thus improve the circuit stability. 2. ** Gain margin **: It is also an indicator to measure the stability of the circuit. It represents the difference between the gain and 1 when the phase difference of the circuit is 0. When the gain margin is greater than 10 dBm, the circuit is considered stable. Negative feedback can increase the gain margin to improve stability. 3. ** gain **: The gain of the circuit will change after the introduction of negative feedback. The formula is <Av>= A /(1 + A * Beta)>(where <Av> represents the gain after the introduction of negative feedback,<A> represents the original gain, and <Beta> represents the feedback coefficient). By adjusting the feedback coefficient, the circuit gain can be accurately controlled. Although negative feedback will reduce the gain, it can improve the circuit's linear degree. 4. ** Bandwith **: The formula of the circuit's band width after the introduction of negative feedback is <Bw>= A / (2 Pi * R * C)>(where <Bw> represents the band width and <A> represents the original gain). Negative feedback can increase the band width of the circuit. When there is no negative feedback, the band width of the circuit may be limited by the gain. After the introduction of negative feedback, the band width can be increased while the gain is reduced. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Turn signal malfunction feedback? What does that mean?
Turn signal malfunction feedback referred to the fact that when the turn signal malfunctioned, the car would convey the information of the turn signal malfunction to the driver or maintenance personnel in some way. The malfunction of the turn signal may be manifested as not lighting up, flashing abnormally (such as flashing too fast or too slow), and so on. When the turn signal malfunctioned, this feedback was very important because the turn signal was a warning signal to other vehicles or pedestrians when turning, changing lanes, overtaking, etc. Once damaged, it was easy to cause a traffic accident, so the fault feedback could prompt the driver to detect and repair it in time. For example, when the turn indicator on the instrument flashed very quickly, it was a kind of fault feedback, indicating that the driver had a turn indicator that might malfunction and needed to be dealt with in time. The failure of the turn signal may be caused by many reasons, such as the turn signal relay or fuse being blown, the bulb being damaged, the turn signal switch failing, the circuit being broken or short-circuited, the body control module failing, etc. Different causes of failure may have different feedback methods or require different inspection and maintenance methods. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Traditional Chinese medicine feedback theory
In the feedback theory of traditional Chinese medicine, the term " feedback effect " was mainly derived from the " On Typhoid and Various Disease ". This was a precise feedback system that Zhang Zhongjing had established imperceptibly. In the process of treating diseases in traditional Chinese medicine, it was necessary to judge the accuracy of diagnosis and treatment based on the patient's reaction. The feedback from this system provided the basis for clinical decision-making. The reactions included the reactions after taking the medicine. Some of them were the normal reactions of the patient when the medicine took effect, and some were the symptoms or deterioration of the patient after being treated by the doctor. Through the judgment and analysis of these reactions, Chinese medicine could adjust the treatment plan, reflecting the characteristics of the practice feedback improvement theory in Chinese medicine theory to ensure the effectiveness of the treatment. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Smoke exhaust valve feedback signal in remote reset state
The feedback signal of the smoke exhaust valve under the remote control reset state refers to the response signal sent to the system when the smoke exhaust valve is in the remote control reset state after the fire control equipment is activated, indicating that the current state of the smoke exhaust valve has been reset. For example, in the smoke control system, when the fire valve and smoke exhaust fire valve are manually closed and reset, or the air supply opening and smoke exhaust opening (valve) are opened and reset, these valve movements must be sensitive and reliable. The signals after opening or closing (including the signals under remote control reset) should be able to receive feedback in the fire control room, which is helpful for the fire control system to monitor and manage the entire smoke control system. At the same time, if the feedback signal of the smoke exhaust valve in the remote reset state was abnormal, such as the feedback of the smoke exhaust valve could not be eliminated, it might be that the air valve in the smoke control system was not in the normal quasi-working state. There were reasons such as being opened or closed by someone, short circuit between the air valve and the module, or module failure. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
There is no feedback signal from the main engine when the smoke exhaust fan is started.
There may be the following reasons for the lack of feedback signal from the smoke exhaust fan starting host: 1. In terms of modules: - The module may be damaged. You can directly short-circuit the feedback end of the module to see if there is feedback. If there is no feedback, replace the module. If there is feedback, check whether there is any broken line or poor contact between the feedback line and the terminal. - Under the condition that the module and wires are normal, check the circuit and connection between the feedback terminal of the control cabinet and the normally open point of the starting AC contactors. 2. Routes: - Failure to connect or break the circuit between the fan control cabinet and the module will result in no feedback. - Wrong connection of the feedback output terminal will result in no feedback. - If the multi-wire control panel was used to start the feedback, it was necessary to check whether the feedback wire was connected incorrectly. Generally, the wrong connection or the line falling off would cause feedback problems. 3. Contactor: If the smoke exhaust fan's starting feedback is from the electrical control circuit connected to the input and output module, and the normally open auxiliary contact of the main contactors starts the fan after the fan is started, check whether the normally open auxiliary contact of the main contactors is normal. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The difference between one-way circuit and three-phase circuit
A one-way circuit had only one line and one neutral line. The current flowed from the line to the neutral line. For example, many electrical appliances in our home use a one-way circuit, such as lights and televisions. It is relatively simple, and the voltage is usually 220V. In a three-phase circuit, there were three live wires and sometimes a neutral wire. The voltage between the three wires was 380V. This kind of circuit was commonly used in the industry. For example, some large-scale electric machines used three-phase circuits. The three-phase circuit could provide more power than the one-way circuit, and it was more efficient. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Which is better, a one-way circuit or a three-phase circuit
One-way circuits and three-phase circuits had their own characteristics and were suitable for different scenarios. It was not easy to determine which one was better. From the perspective of transmission cost and non-metallic consumption, under the same transmission power, distance, voltage, and line loss, three-phase transmission lines can save a lot of transmission costs and non-metallic metals. The amount of copper used is about 3/4 of that of single-phase transmission lines. In terms of generators, three-phase alternators were smaller, lighter, and cheaper than single-phase alternators of the same capacity. A three-phase transformer was not only more economical than a single-phase transformer, but it also had two types of output voltage. It could be connected to either a three-phase load or a single-phase load. For the motor, the three-phase motor was simpler in structure than the single-phase motor of the same capacity. It was reliable, cheap, had good performance, stable operation, and high efficiency. Three-phase power sources were easier to generate rotating magnetic fields and were suitable for powering three-phase electric machines, while single-phase circuits were relatively inferior in this regard. However, in daily life scenarios, such as household electricity, a single-phase circuit could meet the electricity needs of electric appliances such as lights, computers, electric kettles, fridges, and 1P air conditioning. Because the power of these appliances was relatively small, 220V single-phase alternating current could be used. In the industry, due to the large power of the equipment, the need for a stable rotating magnetic field, and for economic considerations, most of them used three-phase electricity. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is there a signal in the ICU?
There were some signal-related situations in the ICU. For example, for patients with mild illnesses, once they had difficulty breathing, it was a signal that they needed to quickly go to the ICU ward and use a breathing machine to save their lives. From the perspective of shock-related conditions, the early warning signals of shock included low blood pressure (including absolute low blood pressure, relative low blood pressure, orthostatic low blood pressure, severe low blood pressure, etc.), as well as signals of tissue low infusion, such as changes in consciousness (irritability, apathy, delirium, coma, etc.), decreased urine output (urine output still <0.5ml/kg*h after adequate fluid replacement), clinical manifestations such as cold and wet skin, cyanosis, paleness, mottled skin, and the refill time of capillaries>2s. In addition, from the situation of patients admitted to the hospital's ICU, such as the number of people admitted to the ICU who needed to use invasive ventilation machines every day, the proportion of seriously ill patients who needed to be intubated, as well as the increase in the proportion of patients transferred out of the ICU, the number of patients admitted to the ICU dropped to single digits, etc., could all be regarded as ICU-related signals. These signals reflected the condition of ICU patients, the pressure of the ICU, and the utilization of medical resources. "The Island of Life" is also a wonderful novel. Everyone is welcome to read it!