## Definition/Concept

In simple words, the VCVS or Voltage Controlled Voltage Source is that where the actual source voltage is controlled by the voltage across any element elsewhere in that circuit. Or we can say the terminal voltage is dependent on changing of voltage across any element in the circuit. VCVS is a type of dependent source.

We know that there are two types of sources - dependent sources and independent sources. For an independent source, we will get a constant output or the actual source is not dependent on whatever happens inside the circuit but in a dependent source, we may not get the constant output. It will depend on the current or voltage elsewhere in the circuit.

We also know that there are two main variables or parameters in an electrical or electronic circuit. So any one of them can affect to other. In this case, as the actual voltage source is dependent or controlled by the other voltage elsewhere in the circuit that is why it is known as a voltage-controlled voltage source. So the concept of VCVS is very simple. You just remember that the terminal voltage you get is depended on or controlled by other voltages.

## VCVS Circuit Diagram

Let's see the below circuit diagram. It will help you to better understand the concept. It is a very simple and basic circuit to easily understand the concept. Here, the Vin is the actual input source voltage and Vout is the controlled output voltage. The output voltage Vout along with the whole circuit is called a Voltage Controlled Voltage Source. Here the changes in voltage across the resistor can change the output voltage Vout.

Here, you can see both the input and output sources are voltage sources. And we can get the output voltage as same as the input voltage source. Because here the actual input source(Vin) is controlled by the voltage across the resistor(VR) and we get the controlled voltage(Vout) across the terminal. If the voltage across the resistor is varying the output voltage also be varied. It basically happens due to the voltage drop across the resistor. And it can be done by varying the resistance of that resistor. So, now you may understand the VCVS or Voltage Controlled Voltage Source changes its terminal voltage depending upon the voltage across the other components of the circuit.

The output from a voltage-controlled voltage source is determined by the equation, VOUT = μVIN

Here, VIN = Input Voltage
VOUT = Output Voltage
and μ = Multypying Constant which is sometimes known as voltage transfer ratio.

Remember that μ is dimensionless.

## Voltage Controlled Voltage Source Symbol

Here, you can see the symbol of VCVS. You can see the controlled voltage source is symbolized by a diamond shape in an electrical network.

## VCVS Examples

The common practical examples of a voltage-controlled voltage source or VCVS are batteries, DC Generators, and Alternators where we cannot get the same output voltage the battery or generator produced because they already have some series internal resistance.

Those are the primary sources that actually generate electrical energy. Even we can make a practical VCVS circuit by using passive elements such as potentiometers. Where we can control the output voltage by varying the knob of the potentiometer. The potentiometer basically varies the voltage across its internal resistor and controls the actual source voltage.

An ideal transformer and an ideal amplifier are also common examples of VCVS. Where the primary voltage of the transformer changes the secondary voltage. And the input voltage of the amplifier changes the output voltage(the best example is OpAmp used in non-inverting mode).

What is VCVS(Voltage Controlled Voltage Source)? Examples Reviewed by Author on June 18, 2022 Rating: 5