Hello,

Here I attached a research paper file. On page 28, the two equations at the end yield the first equation on page 29 (Let me name it "equation A"). I am curious in the equation A. It states that there is dc voltage across the coupling capacitor proportional to the duty cycle. But if you look at my scratch paper, I use the superposition theory. Considering DC part first, the DC component across the coupling capacitor would be Vdrv/2 no matter how high is the duty cycle. (Because the impedance of the coupling capacitor is infinite when it is connected to a DC voltage source)

Am I wrong? If so, why it can't be proved in my way?

Thank you
BlackMelon

 

Below is the LTspice simulation of an RC test circuit for a 10Vpp signal with a duty cycle of 20% for the first half of the trace and 80% for the last half.
As can be seen, the voltage across the capacitor (bottom trace) is about 2V for the 20% duty cycle and 8V for the 80% duty-cycle, as the research paper states
See if you can determine why your reasoning is not correct.

 

Below is the LTspice simulation of an RC test circuit for a 10Vpp signal with a duty cycle of 20% for the first half of the trace and 80% for the last half.
As can be seen, the voltage across the capacitor (bottom trace) is about 2V for the 20% duty cycle and 8V for the 80% duty-cycle, as the research paper states
See if you can determine why your reasoning is not correct.


View attachment 116648

Could you please tell me about the code "PULSE (0 10 0 0 0 1us 5us 30)". I want to know about V1 and V2 each too, so I might have some more information to detect my fault.

Thank You
BlackMelon