Tecnico

El Voltímetro

Materiales:
1 Galvanómetro
1 Decade resistor box
1 Power supply
1 Voltimetro
6 connecting wires + alligator clipper

Objetivos:

1. Explicar el funcionamiento delGalvanómetro de D’Arsonval
2. Discutir el funcionamiento del voltímetro
3. Aplicar el principio de funcionamiento del galvanómetro para construir un voltímetro

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A voltmeter is a deviceused to measure the voltage potential between two points in an electrical circuit. First created in the early 1800s, voltmeters were originally called galvanometers. Technically, all voltmeters areammeters, as they measure current rather than voltage. Although current is measured in amps, Ohm's Law, which establishes the relationship between voltage, current and resistance, can be used to scale theamps to volts.

Because all measurable electrical properties are related to each other through Ohm's Law, in practice most voltmeters are actually multimeters capable of measuring voltage, currentand resistance. When measuring voltage, a large resistance is placed in line with the coil of the D'Arsonval movement to minimize interference with the circuit being measured. This is also due toOhm's Law, which states voltage is directly proportional to resistance. By minimizing the voltage consumed by the voltmeter itself, a more accurate measurement of the circuit's voltage can be obtained.Current is inversely proportional to resistance; conversely, to minimize the amount of current flowing into an ammeter, a large resistance is placed in parallel with the coil.

Modern multimeterscome with digital displays and may even use digital measuring techniques rather than a D'Arsonval movement. By incorporating microprocessors, they are also capable of advanced functions such asmeasuring frequency, counting electrical events, and measuring capacitance
Procedimiento:
Para poder construir el voltímetro o el amperímetro necesitamos conocer dos valores intrínsicos del...