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What is a DC Voltage Meter and How Does it Differ from the AC Voltage Meter?

An attenuator is the first step in the DC voltmeter’s operational process. The attenuator receives the measurement-required DC voltage. Attenuators are used to choose a voltage range. When creating a multi-stage amplifier, either a transistor or a field effect type of transistor is employed.

What Does a Voltmeter Mean?

A voltage meter, also referred to as a voltage meter, can be described as a device that gauges the potential difference or voltage existing between the two points present in the electrical or electronic circuit. DC – Direct Current or AC – Alternating Current circuits are typically the two types of circuits that the voltmeter is used for. Nevertheless, specialist voltmeters may also be employed to measure RF or Radio Frequency voltage.

Typically calibrated in millivolts, kilovolts, or volts, a voltmeter aids in measuring voltages.

A voltmeter can be connected in a parallel form to your device to measure the voltage. This configuration is crucial because parallel objects frequently encounter the same or similar potential difference. For the most part, it shares the same drop in voltage with the circuits, which is why it is linked in parallel.

A voltmeter’s internal resistance is also quite high. The reason for this is just to gauge the probable difference between both the circuit’s two points. As a result, this measuring device’s current stays constant. Explaining further, the voltmeter’s high resistance will make it difficult for current to pass through it. That enables the instrument to measure voltage accurately.

What Does a DC Voltage Meter Mean?

Voltage Meter
Voltage Meter

By moving a pointer against by the fully calibrated scale, a DC voltage meter can be described as a gadget that measures whatever DC voltage is applied onto it. The PMMC meter offers a calibrated scale. Be aware that the voltmeter is another name for voltage meter.

You should also be aware that this voltage being monitored passes first through an attenuator then a DC gain amplifier. The DC voltage is input into an attenuator before being routed through DC linked amplifiers to be monitored by a DC voltage meter.

You can question the purpose of first attenuating a signal then boosting it. In order to choose a specific range, the solution towards this question involves the fact that an attenuator can be used. In order to conveniently get voltage readings, it is also necessary to amplify the signal to the point where it is of a magnitude strong enough to divert the PMMC meter’s pointer.

The DC voltage meter can be made by joining a very large resistor in a parallel form with a circuit we would like to determine the voltage in with this instrument in series.

The deflecting torque is produced by this interaction between both fields created by the fixed coils and moving coils. This instrument sees little use since it’s only employed in DC measuring circuits.

DC Voltage Meter Types

The Direct-Coupled Cascaded Amplifier DC Voltage meter and the Chopper Type DC Voltage meter are the two different types of the DC voltage meters. There are two possible designs for the first type of DC voltage meter. The first is to use bipolar junction transistors. Using field effect transistors is the second.

Direct-coupled cascaded amplifier Using BJT

The attenuator in this uses a variety of resistors with appropriate values. NPN and PNP transistors are both employed here, and they are both directly cascaded in order to ensure that there is a reduction in the use of more components. The lesser the components utilized in circuits, the lesser the complexity.

DC Voltage Meter Utilizing BJT

Everyone is aware that a transistor has always been referred to as a current-controlled device when used with the BJT. As a result, resistors must always be connected in series with any device that uses current to alter or control it. As a result, the transistor of Q1 is linked in series with the resistance having about 14M.

This attenuator network would assist in choosing a specific voltage range. Also,  a high output amplifier is created by a network of some transistors linked to one another. When the cascaded amplifier’s amplified voltage enters its PMMC meter, this same pointer there begins to deflect on the calibrated scale. We can use this method to gauge the voltage provided to it.

Cascaded Direct Coupled Amplifier FET-based DC Voltage Meter


Low sensitivity is produced by the BJT-based direct coupled amplifiers, which also places a heavy load on the input circuits. Because of this, the idea of the direct coupled amplifiers using FET was developed. The FET’s high impedance is by far its greatest benefit.

The input circuits connected into the DC voltmeters does not become loaded because of a high input FET impedance. This leads to a substantially higher sensitivity afforded by such a circuit compared to the prior one.

The connecting design of the DC voltmeter employing a FET and a BJT are identical. The fact that this FET is now a voltage-controlled device is the only distinction. This resistance network attached to a voltage-controlled device is therefore always in shunts.

DC Voltage Chopper Type Meter

The shortcomings of the Direct-Coupled Amplifier DC Voltage meter were addressed by the development of the Chopper DC Voltage Meter. The issue of drift was significant. By employing modulators and capacitors, the drift issue in DC voltmeters of the chopper type can be solved.

The Chopper DC voltmeter’s circuit gives us a quick overview of how it operates. A chopper modulator transforms a DC voltage that needs to be measured into an AC signal. An AC amplifier then receives the AC signal. The drift problem is resolved by the capacitors employed prior to and following the amplifier circuits. With a chopper demodulator, an AC signal is transformed into a DC signal and then sent through a low pass filter ensuring the elimination of AC ripples where present.

AC Voltage Meter vs DC Voltage Meter: What’s the Difference?

The main distinction between an AC and a DC voltage meter is that the latter measures the DC voltage’s peak value while the latter measures its RMS value. The operating principle of each type of voltmeter—DC and AC—distinguishes them from one another significantly. This DC voltmeter chooses a specific voltage, mitigates the remainder of the voltage range, amplifies the chosen voltage, and then transmits it into the PMMC meter.

Before amplifying a signal, an AC voltmeter utilizes the rectifier to convert the AC signal into DC. The DC is then sent to a moving coil magnetic meter to change the pointer’s indication and measure the AC voltage’s RMS value.

The permanent moving coil meters, multistage DC amplifiers, and attenuators are all parts of DC voltmeters. The DC voltage’s peak value applied to your DC voltmeter is measured.

The attenuator, multistage amplifier, rectifier, and PMMC meter are all components of a AC voltage that should be measured. AC voltmeter circuits receive the measured voltage as input. Rectifiers are used to transform AC electricity into DC voltage.

Key Variations Between the AC and the DC Voltage Meter

The main distinction between an AC and DC voltage meter is the measurement quantity. As opposed to measuring AC voltage, this DC voltage meter helps in measuring DC voltage.

The fact that the DC voltage meter doesn’t utilize a rectifier before a multistage amplifier is another significant distinction between a DC voltmeter and an AC voltmeter. AC voltmeter on the other hand makes use of a rectifier before a multistage amplifier.

The AC voltage’s RMS value is measured by an AC voltmeter, whereas the DC voltage’s peak value is measured by a DC voltmeter.

What are the Uses of the Voltage Meters?

You will eventually need to utilize a Voltmeter for measuring the different voltage levels when analyzing the electronic and electrical circuits operation or attempting to comprehend why the circuit fails to function as planned. Voltmeters are devices used for measuring voltage. They can be digital or analogue, or they can be a standalone device or a part of the digital multimeter, which is now more widely used.

Voltmeters may be employed to measure sinusoidal AC voltage as well as DC voltage, however adding one as a tool for measurement into the circuit may disrupt its operation in a steady state.

A “Voltmeter” can be described as the device that, because its name suggests, measures voltage (V), or potential difference that exists between any two locations in a circuit. The voltmeter should be attached in a parallel form with a component which voltage you want to measure in order to measure voltage.

A drop in voltage across one supply or component can be measured using a voltmeter, as well as the total voltage drop across multiple places or components inside the circuit.


An important component of the instrumentation of electronics is a DC voltage meter. This exact application we are dealing with determines whether to utilize an AC voltmeter or DC voltmeter. You should make use of the DC voltage meter when handling DC circuits.

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