# What is the effect of overdampening in a circuit?

• kickthatbike
In summary, the conversation discusses the concept of overdamping in a circuit and compares it to other physical systems such as a mass-spring system and a pendulum. Overdamping in a circuit is analogous to a pendulum swinging in honey due to the dissipation of energy. The conversation also touches on the different types of damping, including underdamping and critically damped, and the role of resistance in causing overdamping.
kickthatbike
This is more of a conceptual question.Would overdampening in a circuit (from a resistor) be analogous to stretching a spring past critical distances in a mass-spring system? Or perhaps swinging a pendulum from excessively large angles?

kickthatbike said:
This is more of a conceptual question.Would overdampening in a circuit (from a resistor) be analogous to stretching a spring past critical distances in a mass-spring system? Or perhaps swinging a pendulum from excessively large angles?

No, not really. Damping (not dampening) refers to the amount of energy lost relative to the amount of energy stored. Overdamping in an electrical circuit is more analogous to a pendulum swinging while submerged in honey. If you pull back the pendulum and release it, it will slowly fall back to its lowest position without oscillating, because the friction with the honey dissipates energy and limits how fast the pendulum can move.

So something like air friction while falling?

kickthatbike said:
So something like air friction while falling?

That's closer. In fact, if air friction is assumed proportional to speed, then it's an exact analog.

But, 'overdampening' refers to an oscillatory system. So if you had a mass on a spring, with air dampening the motion, then the diff. eq. would be the same as if the mass were dampened by a dashpot or similar device. And there would be a minimum dampening constant of air friction that resulted in an overdampened system.

kickthatbike said:
So something like air friction while falling?

Right. But a pendulum in air would be considered damped, but not overdamped. So it would oscillate back and forth, with the amplitude of each swing getting smaller and smaller. This would be considered underdamped. An overdamped pendulum is when the friction is so large that it doesn't oscillate at all, but slowly swings back to it's equilibrium position. There is another possibility, called critically damped, in which the damping is just right so that the pendulum settles into its equilibrium position as quickly as possible.

1 person
So if I understand this right, an overdamped circuit would discharge it's capacitor, and then settle down to have no current, as opposed to the capacitor and inductor working to keep a steady current? And all of this would be caused by a high amount of resistance (literal resistance, from a resistor)?

kickthatbike said:
So if I understand this right, an overdamped circuit would discharge it's capacitor, and then settle down to have no current, as opposed to the capacitor and inductor working to keep a steady current? And all of this would be caused by a high amount of resistance (literal resistance, from a resistor)?

The current would exponentially approach zero without reversing direction if damping is critical or higher.

If there is even a small reversal of current, you'd have underdamping.

1 person
Very rad. Thanks to both of you.

## What is dampening in a circuit?

Dampening in a circuit refers to the process of reducing or controlling the amplitude of a signal, usually an electrical current or voltage, in order to prevent it from becoming too large or unstable.

## How does dampening work in a circuit?

Dampening in a circuit is typically achieved by using a resistor or other component to absorb excess energy from the signal. This reduces the amplitude of the signal and helps to maintain a stable and consistent output.

## Why is dampening important in a circuit?

Dampening is important in a circuit because it helps to prevent the signal from becoming too large or unstable, which can cause damage to the circuit or affect the accuracy of the output. It also helps to maintain a consistent and reliable signal.

## What are the different types of dampening in a circuit?

There are two main types of dampening in a circuit: passive and active. Passive dampening involves using passive components, such as resistors, to absorb energy from the signal. Active dampening involves using active components, such as transistors, to actively control the amplitude of the signal.

## How can dampening be adjusted in a circuit?

Dampening in a circuit can be adjusted by changing the value of the component used for dampening, such as a resistor. The higher the resistance, the more dampening will occur. Additionally, active dampening can be adjusted by changing the settings or characteristics of the active component being used.

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