how do you measure voltage drop?

Question

This is an electronics question on how do you measure voltage drop I need what position the swich needs to be turned to. If you measure with current flowing. And how you attach the meter in the circuit.

Answer 1

By 'switch' I'm guessing you mean the selector switch on your multimeter. If it's a DC circuit, it needs to be set to 'DC Volts'. If it's an AC circuit, it needs to be set to 'AC Volts'. It's usually a good idea to start with the highest range setting either function and then reduce the setting until you get a useable reading.

When talking about 'voltage drop' there must be current flowing in the circuit. If there is no current, there can be no voltage drop across any element of the circuit.

To measure the voltage drop across an element of teh circuit, connect the meter leads directly across the terminals of the element.

HTH ☺


Doug

Answer 2

A Voltmeter (set to either a.c. or d.c. depending on the supply) is used to measure potential difference or "volt drop". You place the meter across the load (in parallel). This will give you the voltage reading. But to measure 'volt drop' you will either be making multiple measures of voltage along a series circuit or introduce a variance in input to the circuit with regard to the resistance, impedance, inductance or similar and measuring the resulting change in voltage.

Most commonly 'volt drop' testing is employed as easy way to "pressure test' series circuits with common and multiple elements. Such as d.c. motor field and armature windings.

Answer 3

With a voltmeter.