Which component is used with a voltmeter for a three-phase alternator to save money?

In a three-phase alternator setup, a selector switch is utilized with a voltmeter to measure the voltage of each phase while minimizing costs. Instead of needing separate voltmeters for each phase, which can be expensive, a selector switch allows a single voltmeter to measure the voltage across different phases one at a time. This approach optimizes resources since the voltmeter can effectively switch between phases without the necessity of multiple devices, thereby saving money and space while still providing accurate measurements for each phase.

Using a transformer, resistor, or capacitor for this purpose would not yield the same financial benefits as employing a selector switch. While those components can have various applications in electrical systems, they do not serve the function of enabling sequential phase voltage measurement as efficiently and economically as a selector switch.