What is inverter technology

Inverter technical terminology refers to:

Impedance: Impediments to AC power in circuits that contain resistors, inductors, and capacitors. Capacitive three-point oscillator (also called the Kotz oscillator): A type of self-oscillating oscillator. It consists of a series capacitor, an inductive loop, and a positive feedback amplifier. Because the three ends of the two series capacitors of the oscillation circuit are connected to the three pins of the oscillation tube, they are named.

Loop filter: A low-pass filter with the following two functions: Attenuate high-frequency error components at the output of the phase detector to improve the anti-jamming performance; When the loop jumps out of the locked state, improve the loop for short-term storage, And quickly restore the signal.

Differential circuit: A circuit in which the output voltage is differentially related to the input voltage and consists of a resistor and a capacitor.

Vco oscillator: In the oscillation circuit, the voltage control element is used as the oscillator of the frequency control device, and vco is the abbreviation of the voltage controlled oscillator.

Minimum frequency shift keying (gmsk) is a modulation technique that saves frequency resources by making the modulated spectrum main lobe narrower and sidelobe fading faster, thus satisfying the requirements of the channel width of the gsm system of 200 KHz.

Pcm coding (also known as pulse code modulation): One of the coding methods of digital communications. The main process is to sample voice, image and other analog signals at regular intervals to make them discretized. At the same time, the sampled values ​​are rounded and quantized in hierarchical units, and the samples are represented by a set of binary codes. The amplitude of the pulse.

Tdma and carrier frequency multiplexing technology are used in time division: The gsm system adopts frequency division multiplexing technology. The whole operating frequency band is divided into 124 pairs of carrier frequencies, and the carrier frequency interval is 200khz, and the duplex interval is 45mhz. The uplink frequency band (mobile station to base station) is 890mhz-gl5mhz, and the downlink frequency band (base station to mobile station) is 935mhz-960mhz. The frequency of the carrier pair with sequence number n (n=l~124) in the uplink and downlink frequency bands can be used as fu(n)=890+0.2nmhz(uplink) or fd(n)=935+0.2nmhz=fu(n) +45mhz (downwards). In each radio frequency channel, the gsm system adopts the time division multiple access technology. Each carrier frequency is divided into tdma frames according to time, and its frame length is 4.6 ms; each tdma frame is divided into 8 time slots, and the time slot length is 557 ps. Therefore, there can be 8 mobile phones working on one carrier frequency at the same time (one mobile phone occupies one time slot). The same time slot number is used when the gsm mobile phone receives the transmission, and the start time of the received tdma frame is delayed by 3 time slots relative to the start time of the transmitted tdma frame, so that the time receiving transmit time slots are separated, that is, the tdma frame. The interleaving avoids the interference caused by the simultaneous reception of the gsm at the same time, so the gsm handset does not use an expensive duplex filter, thereby reducing the cost.

Digital signal modulation and demodulation technology: gsm system In order to meet the stringent requirements of mobile communications for adjacent channel interference, a Gaussian filter minimum shift key modulation method (gmsk) is adopted. This gmsk modulation method has a modulation rate of 270833 kbyte, and each time division The address tdma frame occupies one time slot to send a burst of pulses whose burst rate is 33.86 kilobytes.

Anti-jamming, anti-fading technology: The gsm system uses cyclic redundancy code speech data for protection to improve error detection and correction capabilities (ie, channel coding techniques). The 456-bit data in one speech frame is dispersed into the adjacent eight TDMA time frames. Even if a time-division multiple access TDMA frame is lost, it can be recovered by channel coding. The adaptive equalization technique is used to solve the multipath fading. The resulting delay spread leads to symbol crosstalk; using a pseudo-random frequency hopping sequence (217 frequency hopping per second, ie one frequency per frame hop) solves the problem of co-channel interference and frequency selective fading.

Speech coding and decoding technology: The gsm system uses a regular-pulse-excited linear predictive coding and decoding scheme with a long term, rpeltp scheme. The speech is divided into speech frames of 20ms one frame for encoding, and 260bit speech frames (with a coding rate of 13kbo) are generated. Ensure voice quality and increase spectrum utilization.

Modulation: Modulation is to "add" an audio signal to a high-frequency oscillation wave, and use the audio signal to control the parameters of the high-frequency oscillation.

Demodulation: The process of taking out an audio modulated signal from a modulated wave is called demodulation.

Oscillator: A combination of circuits that converts DC power to a frequency AC signal output.

Oscillation circuit: A circuit consisting of reactance elements that integrate total or distributed parameters.

Phase-locked loop (pll): It is a kind of control system that realizes phase automatic locking. It generally has a phase detector, loop filter, voltage controlled oscillator and other components.

d/a conversion circuit: also known as "digital membrane quasi converter", referred to as "digital membrane converter". A circuit that converts a digital quantity to its corresponding analog quantity.

a/d conversion circuit: also known as "analog-to-digital converter", abbreviated as """卞", which quantizes (discretizes) the amount of analog or continuous change, and converts it to the corresponding digital output. Circuit.

Microprocessor: The computer system can independently execute programs and complete the processing and processing of data and instructions. It consists of a data processing unit, an instruction processing unit, and a memory controller. According to different execution functions, it can be divided into central processor, peripheral processor and interface communication processor.

Memory: Also known as "memory device." It is a device for storing data and various programs in a microprocessor. Is an important part of the microprocessor, from the memory unit aggregate, address registers, decoding drive circuit. Sense amplifier and timing control circuit composed of several parts.

Filtering: A frequency selection technique that filters only the spectrum required in a signal and filters out other spectrums. Its basic form is to utilize the frequency reactance characteristic of the inductor and the condenser, combine the inductance, capacitance appropriately in the circuit, make up the filter network and finish the choice of frequency. The actual inductor and capacitor network can also perform band transmission and suppression. In addition, there are resonator filters made of piezoelectric crystals, piezoelectric ceramics, and mechanical vibrators, as well as various active filters. They have strong frequency selection performance and have become more and more widely used.

Acoustic surface filter: A layer of metal film is evaporated on a material substrate having a piezoelectric effect, and then photolithography is performed to form a pair of interdigital electrodes at both ends. When a signal voltage is applied to the transmission transducer, an electric field is formed between the input finger electrodes to cause the piezoelectric material to mechanically vibrate (ie, ultrasonically) propagate to the left and right sides in the form of ultrasonic waves, and the energy toward the edge side is generated. Absorbed by sound absorbing material. At the receiving end, the mechanical vibrations are converted into electrical signals by the receiving transducer and output by the interdigital electrodes.

Varactor: Also known as "variable reactance diode." It is a kind of diode that uses pn junction capacitance (or the contact barrier capacitance and its reverse bias voltage vr dependence and principle). The materials used are mostly silicon or arsenide single crystals, and the use of epitaxial process technology. The larger the bias voltage, the smaller the junction capacitance.The varactor diode has a series resistance that is related to the resistivity of the substrate material.The main parameters are: zero bias junction capacitance.Zero bias merit, reverse breakdown voltage, center reverse Bias, nominal capacitance, capacitance change range (in picofarads) and cutoff frequency, etc. For different applications, variable-capacitance m-tubes with different c and vr characteristics should be used, if there is an ESC dedicated to the tuning of the resonant circuit. Variable-capacitance diodes, parametric varactors suitable for parametric applications, and power step-varying diodes for frequency multiplication and phase shifting in solid power sources.

In-phase: Refers to the phase difference of two alternating currents of the same frequency equal to zero or an even multiple of 180 degrees.

Inverting: Refers to the fact that the phase difference of two ACs with the same frequency is equal to 180 degrees or an odd multiple of 180 degrees.

Orthogonal: refers to the phase relationship between two alternating currents of the same frequency with a phase difference of 7 ta.

Tuning: Refers to the process of changing the reactance parameters of the tank circuit and making it resonant with the applied signal frequency.

Detune: Also called maladjustment. Refers to the deviation of the natural frequency of a resonant system from the external frequency acting on the system.

Frequency Offset: The abbreviation of 'Delay Rate Offset', which refers to the maximum deviation of the instantaneous frequency of the FM wave from the carrier frequency.

Fundamental Wave: Also known as "first harmonic." It refers to the wavelength or frequency component corresponding to this period contained in the non-harmonic periodic oscillation.

Harmonic: A sine wave whose frequency is n times the fundamental frequency, together with the fundamental wave, is a spectral component of an unharmonic periodic oscillation.

Channel: The medium or channel through which information is transmitted in a communication system.

Coding: In the sending end, in order to achieve the intended purpose, the original signal is processed according to certain rules.

Decoding: refers to the process of converting the pulse code modulation signal into the pulse amplitude modulation signal by the receiving end using a program opposite to the coding. The main equipment consists of some logic circuits and constant current sources.

Frequency division: A method of converting a higher frequency signal to a lower frequency signal.

Frequency multiplication: A method of converting a lower frequency signal into a higher frequency signal. Usually a non-linear circuit is used to generate a series of harmonics from the fundamental wave, and then the required multiples of harmonics are selected by a band-pass filter to achieve frequency multiplication.

Mixing: The process by which two different frequencies of electrical oscillations are changed into electrical oscillations at a new frequency by a non-linear device.