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Questions related from Lutz von Wangenheim
The "Double-Integrator-Oscillator (DIO)" cannot fulfill Barkhausen´s loop gain criterion for oscillation. In a short paper I have explained why this circuit nonetheless is able to oscillate at the...
30 June 2020 1,150 7 View
For WIEN oscillators (see the figure) it is common practice to use the gain stage for limiting the amplitudes before supply voltages can cause hard clipping (and heavy distortions). Amplitudes are...
12 January 2017 9,144 38 View
Now, I like to start a short discussion about some "stumbling blocks" which may appear during circuit simulation. Here is my example circuit: * Inverting opamp amplifier circuit with closed-loop...
03 December 2016 5,917 50 View
There are negative feedback arrangements (control systems), where the loop gain phase crosses the -180deg line twice (in different directions, of course) - and the magnitude of the loop gain...
12 November 2016 6,395 72 View
Recently I came across with the shown circuit. It has some interesting properties. Is there anybody who has used such a circuit already? Both opamps are assumed to be ideal.
08 February 2016 9,330 63 View
I must admit that my question is a bit "provocative" because I know the answers. Yes, unfortunately, it seems that there are two possible answers. An engineer educated in control systems most...
01 February 2016 1,686 21 View
In several documents it is claimed that Barkhausens (necessary) criterion for a feedback circuit to oscillate applies to linear active circuits only...
17 August 2015 6,099 49 View
Because I am not a native english speaker I am not quite sure about the difference (if any) between those two terms. Can anybody explain the difference in usage?
11 August 2015 8,639 14 View
The EARLY voltage is a definition rather than a real existing and measurable quantity. It can be found using the slope of the output chracteristics Ic=f(Vce). Here, we have two alternatives:...
01 June 2015 7,345 20 View
This is not a pure technical question but - more or less - a question when and how these shortcuts are commonly used. I know the meaning behind CFOA - Current Feedback Operational Amplifier. And I...
30 January 2015 5,589 13 View
The generalized impedance converter (GIC) topology introduced by A. Antoniou is known to be a very versatile functional block for realizing active filters and oscillators. My question is: How can...
13 November 2013 793 58 View
Inspired by * Erik Lindberg´s recent contribution (The oscillator - principle of nature), and * a discussion in RG about analogy between electrical and other technical systems I wonder if there...
07 October 2013 2,627 13 View
Primarily, my question concerns „linear“ oscillator circuits in feedback topology. (I know they are, in fact, non-linear - but which circuit is really linear?.) Some time ago there was a...
18 June 2013 7,968 0 View
It is known that the presentation/formulation of the FOURIER spectrum is simplified by using the concept of "negative frequencies". In the following document (see link) it is claimed that negative...
14 May 2013 4,400 28 View
I must admit that my question sounds purposely a little provocative. But I accidentally came across the circuit described below, which exclusively works in the linear part of its operational...
01 January 1970 8,977 8 View
01 January 1970 7,821 3 View
