It is very important to realize that in power supplies with capacitive filtering the input current is not some phase-shifted sinusoid but high-amplitude sort of "rounded spikes" occurring ONLY when the instantaneous input voltage exceeds the voltage held on the filter capacitor. During most of the AC cycle there is zero input current. A simple concept such as phase angle doesn't really come into play in the "bad" power factor but the objective is still to have current that is sinusoidal in phase with the voltage. Reverse recovery time in the output diode of the PFC converter is extremely important and likely to be the parameter that most limits the field of choices. Active PFC circuits require what appears to be paradoxical behavior. The average input current must be inversely proportional to the average input voltage but the instantaneous input current must be directly proportional to the input voltage.
Thanks for the video, great information, but at 5:09 your bridge rectifier schematic is wrong. You have the ground and DC voltage output mixed up with the AC input. At 10:10 you show the "surge diode," along with the incorrectly drawn bridge. The surge diode would cause current to bypass the inductor every time the FET is ON.
@@RGBEngineering You're welcome. I meant it to be constructive, and I think your videos are great explaining the theory. Your explaination of PF using the example of current / voltage phase is excellent. Thanks!
It is very important to realize that in power supplies with capacitive filtering the input current is not some phase-shifted sinusoid but high-amplitude sort of "rounded spikes" occurring ONLY when the instantaneous input voltage exceeds the voltage held on the filter capacitor. During most of the AC cycle there is zero input current. A simple concept such as phase angle doesn't really come into play in the "bad" power factor but the objective is still to have current that is sinusoidal in phase with the voltage.
Reverse recovery time in the output diode of the PFC converter is extremely important and likely to be the parameter that most limits the field of choices.
Active PFC circuits require what appears to be paradoxical behavior. The average input current must be inversely proportional to the average input voltage but the instantaneous input current must be directly proportional to the input voltage.
Thank you for your detailed insights on power factor correction!
I've heard of power factor before but never really looked to see what it is. This is a great explanation. Thanks!
Glad it was helpful!
Thanks for the video, great information, but at 5:09 your bridge rectifier schematic is wrong. You have the ground and DC voltage output mixed up with the AC input. At 10:10 you show the "surge diode," along with the incorrectly drawn bridge. The surge diode would cause current to bypass the inductor every time the FET is ON.
Thanks for the info!
@@RGBEngineering You're welcome. I meant it to be constructive, and I think your videos are great explaining the theory. Your explaination of PF using the example of current / voltage phase is excellent. Thanks!
This video is so good it looks like it's made by AI. Thanks a lot my guy!
Thank you very much :)
Ah yes intredasting, I know some of those words
Thank you for watching :)