AoE 2L.2.1 - Low-pass filter w sinusodial wave

110

02:03:44

I selected the resistor and capacity values very close to the example in the book. 
The -3dB frequency f3dB is 964 Hz.
I built the circuit in my lab and got these measurement results for Vout(ss):

0.01 * f3dB: 10 V
0.1 * f3dB: 9.7 V
1 *  f3dB: 7.07 V
2 *  f3dB: 4.28 V
4 *  f3dB: 2.36 V
10 *  f3dB: 1 V
100 *  f3dB: 0.1 V
1.000 *  f3dB: 0.01 V
10.000 *  f3dB: 0.0058 V

The simulation is very close to measurement values. Even for 10.000 *  f3dB = (9.6 MHz) this works, but the transient plot in EveryCircuit is very cryptic. Remark: To see this, you have to close the transient plot for Vin first.

Reference: Thomas C. Hayes, Learning the Art of Electronics, Cambridge University Press, 2016, page 81

published 10 years ago

hurz

10 years ago

Ok, you think the "transient" plot is cryptic? Or do you mean the Bodeplot mode. The one you start simulation with the 'F' triangle button?

hurz

10 years ago

The bode mode is actually quite cool. Check this, its your example http://everycircuit.com/circuit/6332928559153152

ahmedalsobihy

10 years ago

100

ahmedalsobihy

10 years ago

Thyristor

rigo59

10 years ago

@hurz: Two answers: 1) Thank you for your advice. I tried the Bode-plot, but I didn't succeed to get your nice results. What is the "trick" you are using? I can`t find any parameter settings for the Bode-Plot. 2) With "cryptic" I meant the transient plot in this configuration: - Close the Vin plot (violett) - Set frequency of the generator to 9.6 MHz and see the result. I think there are some "numerical" artefacts, due to the discretization of the solver.

hurz

10 years ago

1) the bode plot is easy, first set the input voltage to 1V peak, this represents 0dB! From there any attenuation or gain is show relative to this 1V. 2)this is a EC bug, tuning the frequency to high while running simlation cause some strange rectangular wave shape. This is what i guess you see. Workaround is easy, just restart simulation at that high frequency if the shape is getting strange. Hope this helps.

rigo59

10 years ago

@hurz: Thank you!

hurz

10 years ago

You are welcome!

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.