# Transient response of LCR circuit

We study the time evolution of the voltage across the capacitor in an LCR circuit by applying a 5 to 0 volt step. Depending on the values of the parameters L,C and R, there are three different cases: Underdamped, Critically damped and Overdampped.

Connect the Inductor from OD1 to A1 and capacitor from A1 to GND. To change the damping factor add a resistor in series with the inductor, or change the value of the capacitor. The python program to plot the response is shown below

from pylab import *import expeyes.eyesj, expeyes.eyemath as em

p = expeyes.eyesj.open()

NP = 150 # number of readings

tg = 10 # time gap between them, keep NP*tg around 3*RC

p.set_state(10,1)

p.enable_set_low(10) # OD1 go LOW before capture

t,v = p.capture_hr(1,NP,tg) # choose NP*tg according to RC

plot(t,v)

show()

The plots shown are for L=140 mH and C = 0.01 uF and C = 1 uF. The graph can be fitted with a damped exponential to extract the frequency and damping factor. The figure below shows the experimental data and the fit, along with the extracted parameters.

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