I am following this article Robust OP Amp Realization of Chua's Circuit by Kennedy to implement a Chua's circuit. I use exactly the same design as the article; the only difference is that I use a 15mH inductor instead of 18mH.
I have finished the circuit, but I don't have an oscilloscope at the moment, so I simply connect a voltmeter across C1(see diagram below).
Since the voltmeter can only read the average value across a period of time(that should be approximately the value at the center of a "scroll" in the diagrams below), I cannot see the wave pattern of oscillation. I believe that the reading of voltmeter should be the value at the center of a scroll on the oscilloscope.
when I connect the voltmeter, I observe the following:
- As I decrease $R$ from $2k\Omega$ to $1.1k$, the reading of voltmeter decreases.
- When $R=2k\Omega$, the voltage across C1 is $6V$, but this quickly decreases as $R$ decreases. When $R<1000\Omega$, the p.d. is less than several hundred $mV$s
- If $R$ is kept constant, then voltmeter readings are stable: changes only appear to the 3rd decimal place.
Are those observations expected for a correctly implemented Chua's circuit? Or are those observations indicating that something is wrong?