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What is the working principle of optical fiber transceiver

  Transceiver is a device for signal conversion, which usually refers to optical fiber transceiver. The emergence of optical fiber transceiver converts twisted pair electrical signals and optical signals to each other, ensuring the smooth transmission of data packets between the two networks. At the same time, it expands the transmission distance limit of the network from 100 meters of copper wire to 100 kilometers (single-mode optical fiber).   First of all, let's understand what is optical fiber transceiver. Optical fiber transceiver is an Ethernet transmission media conversion unit that exchanges short-distance twisted pair electrical signals and long-distance optical signals. It is also called photoelectric converter in many places. After knowing what is an optical fiber transceiver, let's have a detailed understanding of the working principle and usage of the optical fiber transceiver!   Optical fiber transceivers are generally used in the actual network environment where Ethernet cables cannot be covered and optical fibers must be used to extend the transmission distance. At the same time, they also play a great role in helping to connect the last kilometer of optical fiber lines to the metropolitan area network and the outer network. With optical fiber transceiver, it also provides a cheap solution for users who need to upgrade the system from copper wire to optical fiber, and lack funds, manpower or time.   The function of optical fiber transceiver is to convert the electrical signal we want to send into optical signal and send it out. At the same time, it can convert the received optical signal into electrical signal and input it to our receiving end.   Optical fiber transceivers are generally used in pairs. For example, the optical fiber transceiver (possibly other equipment) in the computer room of the operator (Telecom, China Mobile, China Unicom) and the optical fiber transceiver in your home. If you want to build your own LAN with optical fiber transceivers, you must use them in pairs. General optical fiber transceivers, like general switches, can be used after being powered on and plugged in without any configuration. Optical fiber socket, RJ45 crystal head socket. However, we should pay attention to the receiving and sending of optical fibers, one receiving and one sending, and if not, we can exchange them.

What is the effect of capacitors on car audio?

  As we all know, there are capacitors, resistors, inductors and other electronic components in the passive sound divider of car audio. These three kinds of materials directly affect the performance of speakers. The value of each part is selected according to the original design. To put it more clearly, it is the best sound effect combination in the budget of this product level that the original manufacturer thinks.   A capacitor is an element that stores electric quantity and electric energy (electric potential energy). A conductor is surrounded by another conductor, or the electric field lines emitted by one conductor are all terminated in the conductor system of the other conductor, which is called a capacitor.   The capacitor (c) forms an LCR frequency dividing line with the resistor (R) and the inductor coil (L) on the sound line. When the output signal of the power amplifier passes through the LCR network, the frequency dividing point originally designed by the Institute will be handled and the high and low frequencies will be separately transmitted to different speakers.   LCR network is designed by engineers of various factories, ranging from the simplest two tone channel to the top multi tone channel. The circuit of LCR is also designed by the engineers of each factory. Each audio circuit has from the most basic one capacitor and inductor (first-order frequency division) to multiple capacitors and inductors (multi-order frequency division).   Since the theoretical value phase of the signal passes through the capacitor is reversed by 90 degrees (in the case of zero loss of the capacitor, but it is impossible to achieve with the current technology), and the phase of the signal passes through the inductor is advanced by 90 degrees (the resistance is used to reduce the SPL emitted by the monomer and the grounding effect), it is thought that the signal phase will be restored to the original phase, unless different numbers are used as the design of signal phase difference and impedance correction, Generally, the same number of capacitors and inductors must be used for the complete frequency dividing line. Therefore, the importance of the internal parts of the frequency divider to the sound cannot be ignored.

What method can be used to measure the output ripple and switch transient of the voltage regulator?

  Voltage regulator (AVR) is specially designed for AC brushless generator with matching base wave, harmonic compound excitation or permanent magnet generator excitation (PGM system).   The voltage regulator realizes the automatic adjustment of the output voltage of the generator by controlling the excitation current of the alternating current exciter of the generator. Generator voltage regulator can be used for normal 60/50Hz and mid-frequency 400Hz single-machine or parallel-running generators.   It is important to minimize the output ripple and transient of the switch regulator, especially when supplying power to noise-sensitive devices such as high-resolution ADC, the output ripple will appear distinctly spurious in the ADC output spectrum.   To avoid reducing signal-to-noise ratio (SNR) and stray-free dynamic range (SFDR) performance, switch regulators are usually replaced by low-pressure differential regulators (LDOs), sacrificing the high efficiency of switch regulators in exchange for cleaner LDO output. Understanding these artifacts will enable designers to successfully integrate switch regulators into more high-performance, noise-sensitive applications.   Output ripple and switch transient depend on the regulator topology and the value and characteristics of external components.   Output ripple is the residual AC output voltage, which is closely related to the switch operation of the regulator. Its base frequency is the same as the switch frequency of the regulator. Switch transient is a high frequency oscillation that occurs during switch switching. Their magnitude is expressed in terms of the maximum peak voltage, which is difficult to measure precisely because it is highly correlated with the test settings.   The inductance and output capacitance of the regulator are the main components that affect the output ripple. Smaller inductance produces faster transient response at the expense of larger current ripple; A larger inductance makes the current ripple smaller at the expense of a slower transient response. The output ripple can be minimized by using a low effective series resistance (ESR) capacitor.

What is the low ESR and high ripple current for solid state capacitors

  Capacitors are energy storage elements used in circuits for tuning, filtering, coupling, bypass, energy conversion, and delay. Capacitors are often called capacitors. According to its structure, it can be divided into three types: fixed capacitor, semi-variable capacitor and variable capacitor.   Solid aluminium electrolytic capacitor is short for conductive polymer solid aluminium electrolytic capacitor, and is one of the highest-grade products in capacitor products.   ESR (Equivalent Series Resistance) refers to the series equivalent resistance, which is an important indicator of capacitance. The lower the ESR, the faster the charge and discharge of capacitance. This performance directly affects the decoupling performance of power supply circuit of microprocessor. The advantage of low ESR of solid-state electrolytic capacitance in high frequency circuit is more obvious.   It can be said that the low ESR characteristics at high frequencies are the watershed between the performance differences of solid electrolytic capacitance and liquid capacitance. The ESR of solid-state aluminium electrolytic capacitance is very low, with very small energy dissipation. The very low ESR characteristic of the solid state capacitor under high temperature, high frequency and high power conditions can fully absorb the high amplitude voltage generated between the power cords in the circuit and prevent its interference to the system.   Currently, the power consumption of the CPU is very large, the main frequency is far beyond 1GHz, the peak current of the CPU reaches 80A or more, and the output filter capacitance is close to the critical point of operation. On the other hand, CPUs work in a variety of modes, most of the time in the process of working mode conversion. When the CPU changes from a low power state to a full load state, the large amount of energy required for instantaneous (generally less than 5ms) switching of this CPU comes from the capacitance in the CPU power supply circuit. At this time, the high-speed charging and discharging characteristics of the solid state capacitor can output the high peak current instantaneously, ensuring adequate power supply and ensuring the stable operation of the CPU.