Voltmeter Design
电压表设计
Voltmeters, as well as ammeters and ohmmeters, are designed with the use of a sensitive current detector such as a galvanometer.
电压表、电流表和欧姆表都是利用灵敏电流检测器（如检流计）设计的。
A voltmeter is placed in parallel with a circuit element to measure the voltage drop across it and must be designed to draw very little current from the circuit so that it does not appreciably change the circuit it is measuring. To accomplish this, a large resistor is placed in series with the galvanometer. Its value is chosen so that the design voltage placed across the meter will cause the meter to deflect to its full-scale reading. A galvanometer full-scale current is very small: on the order of milliamperes.
为测量电路元件上的电压降，电压表应并联在电路元件上。电压表必须设计成从电路中吸取非常小的电流，以不显著改变它所测量的电路。为此，一个大电阻应串联在检流计中。其值的选择使得施加在表上的设计电压会使表指针达到满量程读数。检流计的满量程电流非常小：大约在毫安级别。
| Voltmeter concept
电压表概念 | Moving coil meters
动圈式电流表 |
用于设计一个满量程电压为 V = volts 的电压表，所需的串联电阻由下式给出
中文译文中的待填/计算数值依次对应：1：vd 2：rs。实际数值以上方原输入框为准。
DC Circuits
索引：直流电路
| HyperPhysics***** Electricity and Magnetism
HyperPhysics ***** 电学和磁学 | R Nave |
返回