Could anyone help me understand what is undamped in the RLC, in electrical circuit analysis??

you make it sound like you are drowning and need a life preserver :)

a near as i can tell undamped would be when you take the R out of the circuit.

Maybe, to be more specific, set all R's either to zero or infinity. Infinity is for situations such as R, L, and C in parallel.

Bill

-- Fermez le Bush--about two years to go.

What is Pls...? Is it similar to plc? VBG Rob

Electric circuits with both inductance and capacitance can exhibit natural oscillations much like a mass suspended from a spring (the inertia is similar to inductance, the spring similar to capacitance). If there is no friction in the mechanical system (nor resistance in the RLC circuit), then a tiny oscillation will continue for ever. In mechanical systems, sometimes an extra device called a damper is added (such as a shock absorber in a car's suspension). The whole purpose of such dampers is to dissipate energy, thus gradually reducing the magnitude of oscillations (e.g. in a car suspension, you want to dissipate the energy so the magnitude of oscillations drop off in just a cycle or two).

In circuit analysis, a resistance does the same thing. It will dissipate the energy of an oscillating circuit and reduce the magnitude of the oscillations. If you remove all the resistance, it's a lot like removing the shocks in your car. The least little 'bump' will send it into oscillations that will continue for many cycles. Some times this is the desired effect in circuits (deliberate oscillators), sometimes it's not (parasitic feedback).

daestrom