Precision works with its customers to optimize a PFC solution for any specific application. In many cases, audible noise is not a problem. For example, when the power supply is housed in an enclosure with forced air, the PFC Inductor noise is not detectable and allows a lower cost solution. Also, if size is not the highest priority, there are many available options.
Precision can provide additional windings on the PFC Inductor to supply power for the PFC control circuitry. Using a voltage doubler circuit with this bias winding provides a semi-regulated output that is quite stable over the entire duty cycle range.
Power factor is the ratio of the real power to apparent power. Power factor can vary between 0 and 1, and can be either inductive (lagging, pointing up) or capacitive (leading, pointing down). In order to reduce a capacitive (or leading) power factor, an inductor is added to make the power factor equal 1. The whole purpose of making the power factor equal to one is to make the circuit look purely resistive (apparent power equal to real power). |