Voltmeter Design

A variation in the additional circuitry permits the use of the iron-vane movement in the design of a voltmeter. The $1 mA$, $43 Ω$ movement can also be rated as a $43 mV$ ($1 mA \times 43 Ω$), $43 Ω$ movement, indicating that the maximum voltage that the movement can measure independently is $43 mV$. The millivolt rating is sometimes referred to as the voltage sensitivity (VS). The basic construction of the voltmeter is shown in [Fig. 1]. The $R_{series}$ is adjusted to limit the current through the movement to $1 mA$ when the maximum voltage is applied across the voltmeter. A lower voltage simply reduces the current in the circuit and thereby the deflection of the movement. Applying Kirchhoff's voltage law around the closed loop of [Fig. 1], we obtain or In general,

How multirange voltmeter is designed?

One method of constructing a multirange voltmeter is shown in [Fig. 2]. If the rotary switch is at $10 V$, at $50 V$, and at $100 V$,