What is damping?  - Page 1
Forum section: electronics / beginners

author: ali6x944
author_rank: Frequent Contributor
timestamp: April 23, 2016, 05:28:31 am
content: What is damping? and is it good or bad and if bad how to prevent it from happening?help!

author: Skimask
author_rank: Super Contributor
timestamp: April 23, 2016, 06:13:37 am
content: Be a little less specific.Google.Amazing isn't it?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 23, 2016, 06:59:56 am
content: For an LTI, pole-zero system, it is when the auxiliary polynomial equation has only real poles. [I forget if the zeros also have to be real or negative...]That might be accurate enough, within the domain at least (electronic filters, control systems, electrical and mechanical dynamics, etc.), but probably not helpful.Damping is usually a good thing, but too much can be undesirable (e.g., a power supply responds too slowly), and it depends on the situation (an oscillator needs to be underdamped to function).Tim

author: ali6x944
author_rank: Frequent Contributor
timestamp: April 23, 2016, 07:16:39 am
content: http://www.splung.com/content/sid/2/page/damped_oscillationshttps://en.wikipedia.org/wiki/Dampingi already reed this one and i didn't quit understand it, i understood mechanical damping but how could that be applied to electronics, specifically LC and crystal oscillators and resonators, also is ringing in the rising edge of square waves a form of Under damped oscillation, and could damping affect the frequency of oscillation.i have seen a photo showing how the three types of damping look like.here:http://www.splung.com/kinematics/images/damped_oscillations/damped_oscillations.gif

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 23, 2016, 08:09:26 am
content: If you understand mechanical damping then you understand electrical damping.Draw a diagram of the mechanical system: label all the masses, spring constants, and dashpots*.*Loss elements.Relabel masses as capacitors; springs as inductors; dashpots as resistors; forces as currents; and velocities as voltages.You're done! You now understand electrical damping!...or not. But the mechanical analogy is absolutely real, and if you can wrap your head around what a capacitor, inductor or resistor is, you can get this.Tim

author: Gyro
author_rank: Super Contributor
timestamp: April 23, 2016, 09:13:38 am
content: It's also worth remembering that all components have parasitic elements too when using the mechanical analogy.Some components will be 'lossier than others due to their parasitic elements - eg. an electrolytic capacitor has a much lower Q than a polystyrene, an air cores inductor has a higher Q than a ferrite bead. These can be explained by examining their 'equivalent circuit' models, all passive components include R,C,and L parasitic elements that have an effect on the resulting Q of the overall circuit.

author: orolo
author_rank: Frequent Contributor
timestamp: April 23, 2016, 12:13:52 pm
content: Your question is related more to physics than electronics. Esentially, an oscillating system is any physical system that stores some energy E, and where that energy periodically transitions between two manifestations. In a pendulum, total energy transitions from kinetic energy (pendulum speed) and gravitational potential (pendulum height). In a mass hanging from a spring, energy transitions from elastic energy (Hooke's law) and kinetic energy. In a typical electric oscillator, energy transitions from electrical energy stored in a capacitor, and electrical energy stored in an inductor.So a battery is an energy storing system, but it is not an oscillator, because the energy in the battery never changes its nature: electrochemical energy.There are many types of oscillators, but the simplest, linear ones, have the property that the frequency of oscillation (between the two forms of energy storage) is independent of the total quantity of energy stored.Imagine that you take an oscillator and measure how much of the total energy is manifesting in one of the two states: for example, you take a pendulum, and measure its height (potential energy). You will measure a wave in time, as the total energy of the system transitions from potential to kinetic and back. The same with an electrical oscillator: if you measure its electric potential (energy stored in the capacitor), you will get a wave, as the cap stores and discharges the total energy of the system. If you measure the current (energy stored in the inductor) you will also get a wave, but 90 degrees out of phase, because when the capacitor is full of energy, the inductor must be empty, and so on.Most physical system have losses, so your oscillator will slowly lose its stored energy. As this happens, the frequency of oscillation won't change, but the top energy measured in any of the two states will decrease. So if you measure the energy of one kind in an oscillator with losses, you will measure a decaying wave of constant frequency, that is, a damped wave. The decaying rate of the energy is closely related to the oscillator's Q factor.Is damping desirable? It depends. If you are designing a car's suspension system, you want a gentle damping. When the car hits an obstacle, the suspension system stores that bump as energy, and slowly dissipates it. If the energy decays too fast, the driver will feel the whole bump. If the energy decays too slowly, the car will vibrate long after you passed the obstacle. On the other hand, if you are designing a clock oscillator, you want very slow dissipation, since in order to keep the oscillator energized, you need to 'tackle' it periodically, and that introduces harmonics, losses, noise, and other undesirable effects.All this can be formalized with easy and universal physical equations (a Hamiltonian for energy conservation, leading to a linear second order differential equation, with a damping/forcing term added) that you can find in almost any first course physics mechanics course.

author: German_EE
author_rank: Super Contributor
timestamp: April 24, 2016, 10:33:55 am
content: Take an analog meter, preferably one with a sensitive movement such as 100 uA and move the meter from side to side, watch the indicator needle.Now short the meter terminals with a short length of wire and try moving the meter from side to side again.That's damping. The mechanical movement of the meter needle is being converted to electrical energy then converted into heat which is then dissipated into the air

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 24, 2016, 12:03:34 pm
content: Bonus points: do it again, with different components across the terminals: you might not be able to test with a large enough inductor (>100H?), but a capacitor or resistor should show the behavior nicely.A resistor will dampen the movement to a variable amount; the resistance value where damping force is about half, will be equal to the coil resistance (DCR).A capacitor may be able to slow down and accentuate the motion.Tim

author: wblock
author_rank: Regular Contributor
timestamp: April 24, 2016, 01:43:51 pm
content: Quote from: T3sl4co1l on April 24, 2016, 12:03:34 pmWell, a resistor willdampthat movement. Dampening is done with a liquid.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 24, 2016, 02:42:56 pm
content: Quote from: wblock on April 24, 2016, 01:43:51 pmElectric current is an electron fluid inside conductors; resistance is essentially viscosity. What's your point?Tim

author: TimFox
author_rank: Super Contributor
timestamp: April 24, 2016, 02:53:18 pm
content: The important thing about a damping force in a mechanical oscillator is that the damping force is proportional to the velocity and opposes the motion.Friction is a constant-magnitude force opposing the motion.In the electrical oscillator (RLC resonant circuit), the damping results from a resistance in series with the oscillating current and is analogous to the mechanical damping force. (Alternatively, it can be represented as a resistance in parallel with the oscillating voltage.)

author: sarepairman2
author_rank: Frequent Contributor
timestamp: April 24, 2016, 04:47:39 pm
content: this is when you get management to say there is no problem and sales to say the problem is being fixed

author: Cerebus
author_rank: Super Contributor
timestamp: April 24, 2016, 06:09:43 pm
content: Quote from: T3sl4co1l on April 24, 2016, 02:42:56 pmIt's the difference between an automatic spell check and an automatic spelling check.One is done by people with bad spelling and the other is done by witches.[I've been dying for an excuse to trot that one out.]

author: ali6x944
author_rank: Frequent Contributor
timestamp: May 03, 2016, 06:46:18 pm
content: Thanks all that gave alot of help!Thanks alot!