1.The buck converter is capable of kilowatts of output power, but suffers from one serious shortcoming which would occur if the power switch were to fail short-circuited, the input power source is connected directly to the load circuitry with usually produces catastrophic results. To avoid this situation, a crowbar is placed across the output. A crowbar is a latching SCR which is fired when the output is sensed as entering an over voltage condition. The buck converter should only be used for board-level regulation.
1.降压变压器可以产生上千瓦的输出功率，但它有个致命的缺陷，当开关电源发生短路时，输入电源会直接连接到负载电路上，这会导致可怕的后果。为了避免这种情况，要在输出端加上一个断路器。这个电路是一个闭合的可控硅整流器，当输出端被检测到一个过高的电压时，它就被触发工作了。降压型变换器只适合于板级调节。

2.Interconnect effects can play a significant part in the timing and noise characteristics of a circuit.
2.互连的效果对于一个电路的时序和噪声特性都能够起到很显著的影响。

of the major interconnect challenges is to ensure signal integrity as the high-speed pulses move along the total interconnect path, from device to PCB, through the PCB to the back plane, and on out to any network connections which may be present.
3.主要的互连挑战之一是确保高速脉冲通过整个互连路径时的信号完整性，从器件到PCB板，再从PCB板到底板，最后到任何可能出现的网络连接。

4.This is Ohm’s law and can be expressed as the formula:I=U/R . The resistor is generally a linear device and its characteristic forms a straight line when plotted on a graph.
4.这就是欧姆定律,可以用公式表示成I=U/R.电阻器一般是线性器件,它的(伏安)特性曲线形成一条直线.

5.One Ohm is defined as that amount of resistance that will limit the current in a conductor to one ampere when the voltage applied to the conductor is one volt.
5.1Ω的定义是当加到导体上的电压为1V时,使导体的电流为1A时所需要的电阻值.