What is VAC in electrical engineering?

Content

Everything you need to know about VAC
- What is VDC and VAC?
Where can I find VAC?
- RMS voltage 120 VAC
- How to calculate RMS value?
Why do we use VAC?

Do you want to know what the abbreviation VAC stands for in electrical terms? I am a certified electrician and I will cover this in detail in the short article below.

You may see 110VAC or 120VAC labeled on most electronic devices.

Generally, VAC is just a term used in electrical engineering for AC volts. You are probably familiar with DC volts; it is a DC voltage. Similarly, VAC represents AC voltage. The only thing you need to know is that both VDC and VAC represent voltages.

Keep reading for a more detailed explanation.

Everything you need to know about VAC

Many states in North America use 110 or 120 VAC. And you may see these markings on some electronic devices such as computers, current transformers, and digital multimeters. But do you know its meaning?

VAC is the term used to refer to AC volts. So there is no such thing as AC power. It's just the AC circuit voltage.

However, to get it right, you must understand the difference between VAC and VDC.

What is VDC and VAC?

First, you must know about DC and AC in order to understand these two terms.

Direct current (DC)

DC power flows from the negative to the positive end. This flow is unidirectional, and a car battery is one notable example.

Alternating current (AC)

Unlike DC, AC power flows from both sides. For example, in any given second, AC power changes from negative to positive and from positive to negative. The main power supply that comes into your home is the best example of AC power.

V DC and AC

If you clearly understand AC and DC power, you have nothing to understand about VDC and VAC.

Here is a simple explanation.

VDC represents the DC voltage value and VAC represents the AC voltage value. If you take a digital multimeter and examine it carefully, you can see both of these markings. However, if you want to use these settings on a multimeter, you must know which circuits work with DC voltage and which circuits with AC voltage.

Where can I find VAC?

Most areas of North America use 110 or 120 VAC for normal households. You can find this marking on AC devices. However, when it comes to Europe they use 220VAC or 240VAC.

Quick-Tip: The 120 V AC supply voltage varies from 170 V to zero. Then it rises again to 170V. For example, alternating current is repeated 60 times in one second. This is why most AC sources are 60Hz.

RMS voltage 120 VAC

In truth, 120V AC alternates to 170V and drops to zero. This sine wave equals 120 volts DC and is known as RMS.

How to calculate RMS value?

Here is the formula for calculating RMS.

V_RMS V =_PEAK*1/√2

Peak voltage 170V.

Consequently, the

V_RMS = 170*1/√2

V_RMS = 120.21 V

Why do we use VAC?

You will lose some energy every time you try to convert energy from one form to another. Hence, to minimize this energy loss, generators produce electricity at high voltage and transmit it in the form of alternating current.

However, ordinary households do not need high voltage electricity. Because of this, AC electricity passes through a step-down transformer and produces a lower voltage for home use.

important: Most electronic devices do not run on AC power. Instead, they use low voltage DC power. Therefore, low voltage AC power is converted to low voltage DC power by a bridge rectifier.

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