Modification to space - charge - limited current of intense electron beam diode 二極管空間電荷限制電流修正
Two - dimensional geometry effect on space - charge - limited current in axially symmetrical planar diode 軸對稱平板二極管空間電荷限制流的2維效應
It has three kinds starting modes : the slope voltage starting , the limiting current starting and the discrete frequency control starting 該軟起動控制器具有三種起動方式:斜坡電壓起動,限流起動和分級變頻起動。
Compared with the traditional tto , its start - up current is much less , and its larger cylindrical volume allows a higher space charge limit current 對于在電流臨近空間電荷限制電流和大信號時,徑向電子束與徑向間隙內(nèi)微波電場的非線性相互作用過程進行了初步的研究。
Low voltage control circuits and high voltage ldmos whose breakdown voltage is around 600v are integrated on this monolithic switching power supply chip . the limited current of high voltage ldmos is 250ma . output power of the whole circuit is less than 9w 內(nèi)部集成低壓控制電路和耐壓600v的高壓ldmos ,最大輸出電流可達250ma ;此單片開關電源輸出功率小于9w ,外圍拓撲結構可采用反激式結構。
The design of the circuit ? key parameters including pulse width in the level shifter part and delay time of the filter circuit , and the necessity to add a limiting current resistor at source the ldmos were emphatic analyzed . author finished the design of each sub - circuit 對電路關鍵參數(shù)高低壓電平位移脈沖寬度、高端濾波電路濾波寬度的設計及在ldmos源端加入限流電阻的必要性進行了重點分析,完成了各單元電路的設計。
With the application of real - time multi - tasks mechanism and modulization software structure , the controller can set and modify the parameters on - line , collect and process the real - time data of the four - battery charge / discharge devices , termly and digitally regulate the closed loop and monitor the real - time faults , so that the system can control different styles of charging and discharging operate mode such as in constant current style , constant voltage with limited current style and static style 控制器軟件采用實時多任務機制和模塊化的設計思想,通過對蓄電池化成充放電過程中工藝參數(shù)的在線設定修改、實時數(shù)據(jù)的采集處理、定時的數(shù)字閉環(huán)調(diào)節(jié)和故障的監(jiān)測,實現(xiàn)對蓄電池靜電、恒流、恒壓限流等多種充放電工作方式的控制。
Based on the high - low voltage electric driving unit , a new electric driving unit is built , which not only has the advantages of the high - low voltage electric driving unit but also has the advantage of obtaining high limiting current and low maintaining current easily . using self - excitation chopper circuit , the electric driving unit is good efficient , and the heat creating from the solenoid is small 在高低壓驅動電路的基礎上又設計出一種高低壓自激斬波恒流驅動電路,該驅動電路除了具有高低壓驅動電路的功能外,還具有高壓限流和低壓維持電流獲取方便、能量利用更為合理、閥發(fā)熱更少等特點。
By analyzing the charging & discharging characteristics of accumulators , and by improving the hardware and control algorithm of the former chargers , this dissertation designes a high - power charger . the charger can not only charge accumulators with constant voltage and limited current , but also charge them intelligently . meanwhile , it is characteristic of over - voltage , over - current and overheat protection , self - recovery and automatic current - averaged in parallel 本論文通過對蓄電池的充、放電特性的分析以及對以往充電機硬件和控制算法兩個方面的改善,設計了一種不僅能對蓄電池進行恒壓限流充電,還可以進行智能充電,同時具有過壓、過流、過熱保護、自恢復功能和并聯(lián)自動均流的大功率充電機。
The flow characteristics , distributions of current density and chemical components , and the performance of these two different designs are calculated and compared . the flow and mass transport characteristics are analyzed in detail , which indicate that strong forced convection is produced in the interdigitated flow field , which consist of dead - end gas channel that force the gases through the porous electrodes . results of comparison show that forced convection induced by the interdigitated flow field in the diffusion layer effectively enhances mass transport of reactants and products , thus leading to a higher cell performance and the limiting current density 在傳統(tǒng)流道設計的pemfc中,反應物從流道到催化層的供應和生成物從催化層到流道的排出主要是以擴散為主,而在交叉梳狀流道設計中,以流動帶動的對流傳遞則占據(jù)了主導地位,而且這種以對流為主的傳遞機理大大提高了反應物和產(chǎn)物傳遞速率,從而有效地改善了電池的極限電流密度和極化性能等特性。
The limiting current, in electrochemistry, is the limiting value of a faradaic current that is approached as the rate of charge-transfer to an electrode is increased . The limiting current can be approached, for example, by increasing the electric potential or decreasing the rate of mass transfer to the electrode.