Gweithio egwyddor o newid pŵer cyflenwad Tri amodau o newid pŵer cyflenwad
The working principle of the switching power supply The working process of the switching power supply is quite easy to understand. In the linear power supply, the power transistor is made to work in the linear mode. Unlike the linear power supply, the PWM switching power supply makes the power transistor work in the on and off state. , in these two states, the volt-ampere product added to the power transistor is very small (when it is turned on, the voltage is low and the current is large; when it is turned off, the voltage is high and the current is small) / volts on the power device The Ampere product is the loss generated on the power semiconductor device.
The working process of the switching power supply is quite easy to understand. In the linear power supply, the power transistor is made to work in a linear mode. Unlike the linear power supply, the pwm switching power supply makes the power transistor work in the on and off states. In the state, the volt-ampere product added to the power transistor is very small (when it is turned on, the voltage is low and the current is large; when it is turned off, the voltage is high and the current is small) / the volt-ampere product on the power device is the power semiconductor losses incurred on the device. Compared with the linear power supply, the more efficient working process of the pwm switching power supply is achieved by "chopping", that is, chopping the input DC voltage into a pulse voltage whose amplitude is equal to the input voltage amplitude. The duty cycle of the pulse is adjusted by the controller of the switching power supply. Once the input voltage is chopped into an AC square wave, its amplitude can be stepped up or down through a transformer. By increasing the number of secondary windings of the transformer, the number of output voltage groups can be increased. Finally, these AC waveforms are rectified and filtered to obtain a DC output voltage. The main purpose of the controller is to keep the output voltage stable, and its operation is very similar to the linear form of the controller. That is to say, the functional block, voltage reference and error amplifier of the controller can be designed to be the same as that of the linear regulator. The difference between them is that the output of the error amplifier (error voltage) passes through a voltage/pulse width conversion unit before driving the power transistor. There are two main working modes of switching power supply: forward conversion and boost conversion. Although the arrangement of their various parts is very small, the working process is very different, and each has its own advantages in specific applications.
swits
Power electroneg gweithredu yn a newid wladwriaeth yn hytrach na a llinol wladwriaeth
high amledd
Power dyfeisiau electronig gweithredu yn uchel amleddau yn hytrach na isel amleddau agos i diwydiannol amleddau
The newid pŵer cyflenwad allbynnau DC yn lle o AC a can allbwn allbwn amledd uchel AC fel electronig trawsnewidyddion
Dosbarthiad o newid pŵer cyflenwad
in y maes o newid pŵer cyflenwad technoleg, pobl yn datblygu cysylltiedig pŵer electronig dyfeisiau a newid amledd trosi technoleg yn yr un yr un amser un. Y dau promote yr un arall i promote y newid pŵer cyflenwad golau, bach% 2c thin, isel sŵn, dibynadwyedd, datblygu yn y cyfeiriad o gwrth-jamming. Newid pŵer cyflenwadau can yn yn rhannu i categorïau: AC/DC Mae yn AC% 2fACDC/AC fath fel gwrthdröyddion. DC/DC trawsnewidyddion wedi awr wedi wedi'u modiwleiddio, a y dylunio technoleg cynhyrchu prosesau wedi wedi wedi aeddfed yn cartref a dramor. Safoni wedi cydnabyddiaeth gan defnyddwyr, ond y modiwleiddio o AC/DC, due i ei nodweddion nodweddion% mwy technegol a broses gweithgynhyrchu yn y broses y broses o modiwleiddio. Y strwythur a nodweddion o y o math Newid pŵer cyflenwadau yn disgrifio isod.
Datblygu Tuedd o Newid Pŵer Cyflenwad Technoleg
The development direction of switching power supply is high frequency, high reliability, low consumption, low noise, anti-interference and modularization. Because the key technology of switching power supply is light, small and thin is high frequency, so the major foreign switching power supply manufacturers are committed to synchronously developing new high-intelligence components, especially to improve the loss of the secondary rectification device, and in the power iron Oxygen (Mn? Zn) materials to increase scientific and technological innovation to improve the high magnetic performance at high frequency and large magnetic flux density (Bs), and the miniaturization of the device is also a key technology. The application of SMT technology has made great progress in switching power supplies. Components are arranged on both sides of the circuit board to ensure that the switching power supply is light, small and thin. The high frequency of switching power supply will inevitably innovate the traditional PWM switching technology. The soft switching technology of ZVS and ZCS has become the mainstream technology of switching power supply, and the working efficiency of switching power supply has been greatly improved. For high reliability indicators, switching power supply manufacturers in the United States reduce the stress on devices by reducing the operating current and junction temperature, which greatly improves the reliability of the products. Modularization is the general trend in the development of switching power supplies. Modular power supplies can be used to form distributed power supply systems, and N plus 1 redundant power supply systems can be designed to achieve capacity expansion in parallel mode. Aiming at the disadvantage of high operating noise of the switching power supply, if the high frequency is pursued alone, the noise will also increase accordingly, and the use of partial resonant conversion circuit technology can theoretically achieve high frequency and reduce noise, but some There are still technical problems in the practical application of resonant conversion technology, so a lot of work still needs to be carried out in this field to make this technology practical. The continuous innovation of power electronics technology makes the switching power supply industry have broad development prospects. In order to speed up the development of my country's switching power supply industry, we must take the road of technological innovation, walk out of the road of joint development of industry, education and research with Chinese characteristics, and contribute to the rapid development of my country's national economy.
The Dull o Gwella y Effeithlonrwydd o Newid Pŵer Cyflenwad
cut dechrau
For y flyback pŵer supply, y rheolaeth sglodion yn powered gan y ategol troellog troellog ar ôl startup, a y foltedd gostyngiad ar y y startup ymwrthedd is 47kΩ, y pŵer defnydd yn yn nearly 2W. I gwella effeithlonrwydd 2c hwn gwrthydd sianel rhaid fod torri i ffwrdd ar ôl start-up. TOPSWITCH, ICE2DS02G has arbennig cychwyn cylched y tu mewn% 2c a gallu troi oddi ar y resistor ar ôl start-up. Os y controller does not have A arbennig cychwyn cylched, A cynhwysydd can Hefyd fod Connected Gyfres gyda y cychwyn Resistor, y colli ar ôl dechrau can yn raddol Drop i zero. Mae'r anfantais yn bod y pŵer cyflenwad yn ail-ddechrau ei hun, a y cylched can yn yn yn dechrau eto datgysylltu y mewnbwn foltedd rhyddhau y cynhwysydd.
Clock amlder can fod ramped i lawr esmwyth neu yn sydyn. Llyfn dirywiad yn golygu hynny pan y adborth uwch a sicrwydd trothwy, y cloc amledd is linearly decreased through a penodol modiwl .
switch gweithio modd
1. QR→pWM Ar gyfer newid pŵer cyflenwadau gweithio yn amledd uchel modd, newid i amledd isel modd yn ystod wrth gefn can lleihau wrth gefn colled. Ar gyfer a lled-cyseinydd newid pŵer cyflenwad (gweithio amlder o nifer cant kHz i sawl un MHz) % 2c gall fod newid i A amledd isel pwls lled modiwleiddio rheoli modd pWM (tenau kHz) yn ystod standby. Y IRIS40xx sglodion gwella effeithlonrwydd gan newid rhwng QR a pWM. Pryd y pŵer cyflenwad is is dan golau llwyth a wrth gefn mode, y yn bach, Q1 yw troi oddi ar , a y y cyseiniant signal na na throsglwyddwyd y FB terfynell. Y FB foltedd is is is than A A The Threshold Voltage Mode. Be sbarduno, a y cylched gwaith yn A is Rheoli modd.
2. pWM→pFM For switching power supplies that work in pWM mode at rated power, you can also switch to pFM mode to improve standby efficiency, that is, to fix the on-time and adjust the off-time. The lower the load, the longer the off-time and the higher the operating frequency. Low. Add the standby signal to its pW/ pin, under rated load conditions, the pin is high, the circuit works in pWM mode, when the load is below a certain threshold, the pin is pulled low , the circuit operates in pFM mode. Realizing the switching between pWM and pFM also improves the power supply efficiency during light load and standby state. By reducing the clock frequency and switching the working mode, the standby operating frequency can be reduced, the standby efficiency can be improved, the controller can be kept running, and the output can be properly regulated in the whole load range. Responds quickly even when the load surges from zero to full load and vice versa. The output voltage drop and overshoot values are kept within the allowable range.
Controllable Pulse Modd
(BurstMode) controllable pwls modd, hefyd hysbys fel SkipCycleMode (SkipCycleMode), refers i a sicr cyswllt o y cylched a reolir A signal gyda A cyfnod mwy na y y pWM rheolwr pan mae'n is golau llwyth neu standby amodau, felly yn dilys neu annilysu o bryd i'w gilydd, felly y effeithlonrwydd o golau llwyth a wrth gefn gall fod gwella gan lleihau y rhif o switshis a cynyddu y ddyletswydd cylch yn cyson amlder. Mae hyn signal yn ychwanegu i y adborth sianel, pWM signal allbwn sianel, y y enable pWM sglodion (o'r fath fel LM2618, L6565) or y modiwl mewnol o y sglodion (fel NCp1200% 2c FSD200% 2c L6565 a TinySwitch cyfres sglodion).
