【正文】 decrease. Radiator switching voltage stabilizer for grid voltage directly rectifier, filter, and then adjusted by adjusting voltage switch pipe, need not power transformer. In addition, switch frequency for dozens of KHZ, filter capacitor, inductor value. Therefore switching power supply is light weight, small size, etc. In addition, due to the low consumption, low temperature。High frequency switching power supply is traditional rectifier (silicon rectifier, siliconcontrolled rectifier) upgrade alternative products. High frequency switching power supply with convenient use, small size, high efficiency, stable work, coating meticulous etc absolute superiority quickly dominate the market. Widely used in electroplating electrolysis surface treatment industry oxidation and get old and new customers.Product features:一．This product USES imported brand ponents and international advanced bridge in precision machining technology of inverter, and make the performance is stable, the quality is reliable.二．For highfrequency pulse waveforms output ripple coefficient, the 1%, can improve the number of plating and surface aestivation, refuse the gloss and got a dark corner of plating. And can reduce the loss, raw materials of plating industry of special requirements.三．SFG series high frequency switching power supply by airfilled type design, installation convenience. With remote control device, easy for operation. Can bring load switch machine, reduce the adjustment of the plex procedures.四. Small volume light weight the prehensive use of anticorrosive craft, enhance the ability of anticorrosion products, prolong the life.五. Energy saving, high working efficiency reached more than 90%, any more than a linear always voltage matching. Save the traditional rectifier regulator and the energy loss, in more than 35%, greatly reduce the cost, the reason of surface treatment industryHigh frequency switching power supply一． The main circuitFrom the input and output of dc exchange network, including:1．The whole the effect is input filter: there will be the clutter power filter, also hindered the feedback to produce clutter of public power.2．And rectification and filtering: ac power grid directly to a smooth dc rectification, in order to the next level.3．Inverter: after rectifying dc into high frequency alternating, this is the core part of switch power supply, the higher the frequency volume, and weight and output power than smaller.4．And output rectifier and filtering: according to provide reliable, load of the dc power supply.Second control circuit ：On one hand, the sample from the output terminal with setting standards, and then pared to control the inverter, change the frequency or pulse width, achieve output stability, on the other hand, according to the test circuit, the information provided by differential protection circuit, control circuit of various protection measures.Third detection circuit：In addition to providing protection circuit is running in the various parameters but also provide various display meter data.Four, the auxiliary powerTo provide all the different requirements of a circuit switching voltage control principleSwitch to certain time interval K repeatedly through and disconnect the switch, the power input, K E through switch and filter circuits provide load RL, throughout the switch power load during to provide energy, E, When the switch, input power disconnection K E will provide energy interrupted. Visible, to provide the energy input power load is intermittent, for the load can be provided for energy switching power supply, a storage device, must be in switch will be part of the energy stored in the switch to load, release. In the figure, the inductance and capacitance C2 and diode L circuit, is posed of D this function. Inductance used in storing energy, l., and stored in the switch of energy through the diode inductance L D, released to load get steady and continuous energy, because diode D make continuous load current, so called freewheeling diode. In EAB average voltage between AB says: under the type used:EAB = TON/T * EFor every TON of time, the switch to switch the huge T works cycle (. switch time TON TOFF cutoff time and sum).By type, changing switch time and work cycle, the ratio between the average voltage AB also changed, therefore, with the load and the input voltage changes automatically adjusted TON and the proportion of T he can make the output voltage V0 remain unchanged. Change through Time and work cycle TON of pulse that changing proportion of this method, SHCH as Time Ratio Control (from Time, abbreviation for TRC).According to the control principle TRC have three ways:A Pulse Width Modulation (Pulse Width Modulation, the abbreviation for PWM)Switch is constant, by changing the pulse width to change the way SHCH.Second, Pulse Frequency, Pulse Modulation (some Modulation abbreviated PFM)The constant change of the pulse width, through the working frequency switches to change the way SHCH.Third, mix modulationConduction pulse width and switch jobs are not fixed frequency, each other can change the way, and it is more than two ways of mixed.High frequency switching power supply [1] don39。在這種工作方式下，開關(guān)器件按照外加的脈沖信號(hào)，周期的進(jìn)行開通和關(guān)斷。輸出的兩路PWM信號(hào)互補(bǔ)，占空比控制在0%40%之間。因?yàn)?，UC3842的電壓反饋輸入端腳2接地，所以，誤差放大器的輸入誤差總是固定的，改變的是誤差放大器的增益（可將線性光耦中的光電三極管視為一可變電阻）。，該開關(guān)電源的電壓采樣電路有兩路：一是輔助繞組的電壓經(jīng)D1，D2，C1，C2，C3，R9組成的整流、濾波和穩(wěn)壓后得到16V的直流電壓給UC3842誤差放大器正向和反向輸出端之間的電壓差經(jīng)放大器放大后，調(diào)節(jié)輸出電壓，使得UC3842的輸出信號(hào)的占空比變大，輸出電壓上升，最終使輸出電壓穩(wěn)定在設(shè)定的電壓值。驅(qū)動(dòng)電路的基本任務(wù)是將控制電路發(fā)出的信號(hào)轉(zhuǎn)換為加在電力電子器件控制端和公共端之間，可以使其開通或者關(guān)斷的信號(hào)。正電源端(Vcc)和參考輸出(Vref)各由分離的比較器監(jiān)視。在這些條件下，電流取樣比較器門限將被內(nèi)部箝位至1．0V。輸出電壓因兩個(gè)二極管壓降而失調(diào)(≈1．4V)并在連接至電流取樣比較器的反相輸入之前被三分，這將在管腳l處于其最低狀態(tài)時(shí)(V0l)，保證在輸出(管腳6)不出現(xiàn)驅(qū)動(dòng)脈沖。這可通過將時(shí)鐘信號(hào)加到圖2 0所示的電路來完成。： UC3842內(nèi)部結(jié)構(gòu)圖振蕩器：振蕩器頻率由定時(shí)組件RT和CT選擇值決定。驅(qū)動(dòng)能力為177。 示出了UC3842普通電解電容器作為工頻整流濾波是可以完全勝任的，但是隨著開關(guān)電源的開關(guān)頻率的不斷提高，普通電解電容器的ESR和寄生電感將不能很好的適應(yīng)高頻整流濾波的要求。選定原則：變壓器磁通在滿足△Bac+△Bdc Bs，取Iac