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Voltage Divider Calculator


What is a Voltage Divider Circuit?

If you are in an introductory level electrical engineering course, you will probably hear of a voltage divider. Other people that may be interested in learning about voltage dividers include electricians, computer engineers, communication engineers, software engineers, and the technical crowd in general.

We will discuss this concept here with graphs and equations to make you understand with every bit of a voltage divider circuit. But, first, let’s make your thoughts clear. Now, consider a box that can contain a single source or any other combination of circuit elements. It will be hooked up to a few resistors that are all lined up in parallel and we need to calculate the voltage drop across each of the resistors. To properly understand voltage dividers, you should understand the basic concepts behind Kirchhoff’s Current Law and Kirchhoff’s Voltage Law (KVL). Here we will be applying KVL to the resistors that we just spoke about. The law says that the cumulative drop in potential (voltage) across all of the series resistors will sum to the value coming out of our source (box). The voltage potential will start at the value of the source and drop a certain percentage as each of the resistors elements is encountered.

Voltage Divider Circuit

The voltage drops can easily be calculated by using a voltage divider. Consider two resistors in parallel. To calculate the voltage dropped across the 1st resistor, voltage source is multiplied by the value of that resistor and divided by the total resistance. The resulting value is the voltage drop across the first resistor. Consequently, that leaves Vin - Vresistor1 as the value left to drop across the second resistor.

Voltage Divider Calculation

Although a voltage divider seems like a pretty simple and straightforward electrical circuit. The importance of this simple circuit can’t be ignored in electronics. The fundamental reason for a voltage divider circuit is to change an enormous voltage into a little voltage. It uses just input voltage and two series resistors to generate an output voltage. Now let us consider the circuit which we mentioned above, using two resistors R1 and R2. Both the R1 and R2 resistors are in series so

By ohm’s law, we get V=IR

As we have two resistors, so the above equation becomes

V1 =R1i …………… (1)

V2 = R2i …………… (2)

Now applying Kirchhoff's voltage law

-V +v1 +v2 =0

V = V1 +v2

Therefore, the equation becomes

V (t) =R1i + R2i = (R1+R2)


i (t) =v /R1+R2……………. (3)

Substituting 3 in 1 and 2 equations, we get

V1 = R1 (v /R1+R2)

V (R1/R1+R2)

V2 = R2 (v /R1+R2)

V (R2/R1+R2)

This equation shows the voltage divided between the two resistors, which are directly proportional to their resistance. We can utilize this voltage divider rule to broaden the circuits, intended to use multiple resistors as well.

Equation of Voltage Divider

We already drive the voltage divider rule equation, which uses three input values in any circuit, input voltage and two resistor’s values. By utilizing the accompanying condition, we can discover the yield voltage

Vout = Vin x R2/R1+R2

From the above condition, we infer the yield voltage is legitimately relative to the information voltage and the proportion of two resistors R1 and R2.

Examples of Voltage Divider Equation to find Vout or Output Voltage

Example 1: Let’s assume a circuit has two resistors R1 and R2 with the values of 1kΩ and 3kΩ respectively. The Vin or input voltage of the circuit is 12V. Find the Vout or output voltage using the Voltage Divider Equation.

Solution: As we find out the voltage divider equation is

Vout = Vin R2 / R1 + R2

By putting the values of Input voltage and R1 and R2 in this equation, we get

Vout = 12V. 3kΩ/ 1kΩ + 3kΩ

Vout = 12V. 3kΩ/4kΩ

Vout = 12V 3 / 4= 9V

So the output voltage is 9V.

You can check the output voltage of as many input voltages as you want using this simple voltage divider equation. Furthermore, you can also connect as many resistors as you want to bring the output voltage even down. We can look at the solved example, how a voltage divider circuit cut off the 3/4 ratio of input voltage to bring the output voltage down.

Voltage Divider Calculator

As we find out that a voltage divider, is quite a simple circuit having in series resistors to get an output voltage fixed fraction of its input voltage. The divide ratio between input voltages is also straightforward to calculate as two resistors determine it. But still, it becomes complicated to solve or find the output voltage for complex problems using the voltage divider equation by hands. Being human, we can make mistakes, which further can lead to unwanted results. Therefore, to overcome this issue, we bring you the best solution for both worlds. A voltage divider calculator can find the right output voltage for complex circuits using a voltage divider calculator. There are several web-based online voltage divider calculators that you can use to calculate the output voltage based on the voltage divider equation. But if you are looking for the best voltage divider calculators, then outshines every other voltage divider calculator, and we will tell you why. Our voltage divider calculator is one of the easiest to use a calculator that you can find online. It utilizes a pure voltage divider equation or formula to solve your numerical problems most efficiently.

How to use our Voltage Divider Calculator?

You don’t need to be a professional to use our calculator. This is as simple as using any other calculator. You will find three fields

  • Voltage Source (For Input Voltage)
  • Resistance 1 (R1 in Ohm)
  • Resistance 2 (R2 in Ohm)

After entering the relevant values in the appropriate fields, you only need to click on the CALCULATE button. You will get your output voltage within a few seconds, making our tool the easiest to use voltage divider calculator.

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