simbaliya
Member level 4
Below is the architecture
![pfc.jpg pfc.jpg](https://www.edaboard.com/data/attachments/11/11999-79c344947657514efcd785aba38cbf24.jpg)
"Acting as a control signal to the pre-regulator, I M has
an instantaneous value that follows the shape of the input voltage, and an average
value that is inversely proportional to its rms value. Resistor R 3 converts I M to a
voltage while a voltage proportional to the line current is measured across R s, the
line current sensing resistor.
The difference between these two voltages is applied to the input of the current
amplifier. Under closed loop control, the current amplifier will try to keep this
voltage difference close to zero volts. This forces the voltage produced by the return
current on R s to be equal to the voltage across R 3."
For the last sentence I can not understand why, can someone explain in detail?
thks!
![pfc.jpg pfc.jpg](https://www.edaboard.com/data/attachments/11/11999-79c344947657514efcd785aba38cbf24.jpg)
"Acting as a control signal to the pre-regulator, I M has
an instantaneous value that follows the shape of the input voltage, and an average
value that is inversely proportional to its rms value. Resistor R 3 converts I M to a
voltage while a voltage proportional to the line current is measured across R s, the
line current sensing resistor.
The difference between these two voltages is applied to the input of the current
amplifier. Under closed loop control, the current amplifier will try to keep this
voltage difference close to zero volts. This forces the voltage produced by the return
current on R s to be equal to the voltage across R 3."
For the last sentence I can not understand why, can someone explain in detail?
thks!