开关

One change-over switch should be installed in the control box, which can settle how to operate the circuit breaker: by remote or by local.

控制箱内设一个切换开关，确定断路器是在远方或就地操作，并配备一个现场试验开关。

Change-over switch for voltage phase-changed measuring..

起动、停止均可带锁定装置，将开关锁定在起动或停止档，避免误操作，不自动复位。 U 为双控选择开关。

It used chebyshev polynomials to calculate sine function for improving its accuracy. It adopted optimized null vector distribution strategy to decrease switching times and switching current.

其采用Chebyshev多项式计算三角函数，提高了运算精度；采用零矢量象限间交错分布的优化策略，以减小开关次数，降低开关电流。

In this paper,a kind of flexible cantilever beam electromagnetic optical switch which is used in the wave length channel selection system was designed and fabricated. It is manufactured by MOEMS technology and composed of a plane circular coil in flexible polyimide cantilever beam, cylindrical permanent magnet,substrate and reflector prism with two reflecting surfaces.

设计并制作了一种用于波长信道选择系统的新型柔性悬臂梁电磁驱动光开关，该光开关采用MOEMS技术制作，由带有平面螺旋形线圈的聚酰亚胺悬臂梁、圆柱形永磁体、基座以及双面反射棱镜组成。

Only the switchgear door is closed, and closedown state is released, Permit that grounding switch is closed.

开关柜门关闭且当闭锁状态解除后，才允许关合接地开关。

Furthermore, reverse recovery losses of main diodes are minimized, and auxiliary switches commutate at zero current.

此外，续流二极管的反向恢复损耗被降低到最小，辅助开关也实现了零电流开关。

In this paper the commutate circuit principle and work process of the commutate circuit, the composing and work principle of frequency conversion circuit, main switch element IGBT structure feature turn on and turn-off process dynamic and static switch feature and the work principle of invert were analyzed .

本论文分析了整流电路及相控电路的原理和工作过程；变频电路的组成和工作原理；主开关器件IGBT的结构特点、导通及关断过程、动态静态开关特性；逆变电路的工作原理。

In order to solve the application problem of conduction heating machining, this project investigates some problems, such as dynamic characteristics of heating power, features of circuit current and voltage, arc discharge states and so on. It also studies control characteristics of Uni-phase or Tri-phase Direct Current Power Supply and Inverse Switch Power Supply. A High Frequency Inverse Switch Commutate Power Supply is developed.

为了解决导电加热切削的应用问题，从加热电源的动态性能和回路的电流、电压特性及电弧放电状态等方面进行研究，分析比较了单、三相交直流电源和逆变开关电源的特点和控制特性，研制了高频逆变开关整流电源。

Its basic idea is to use ZVS circuit which makes the main circuit of inverter resonate at every beginning of carrier period, so each power devices can be commutate when the voltage of main circuit's DC bus line is zero.

其基本思想是，通过零电压开关电路使逆变器主电路在各载波周期起始时刻产生谐振，确保各功率开关器件在主电路P、N极间电压为零期间进行动作切换。

BSIT compound device is developed. This device consisting of BSIT and BJT has many advantages, such as high switch speed, large power capacity and high h+ temperature stability. It can be used in low voltage switch regulator, pulse power source, instrument enduring a bad environment, and so on.

本文研制了BSIT组合器件，它是由BSIT和BJT组合而成的一种复合器件，具有开关速度高、功率容量大、h_的温度稳定性好等优点，可用于低压开关电源、优质脉冲功率源和高低温恶劣环境下的仪表等场合。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。