According to the working principle of PFC circuit, they are divided into active and passive, can say as a active PFC circuit, two types of passive PFC circuit. The biggest difference between active and passive PFC PFC circuit, is that it has an active booster circuit. It by high-frequency inductance coil, switch valve, high pressure filter capacitor and control IC components, forming a circuit of input voltage can be improved, by raising the input voltage to reduce the current flow in the lower power loss in the circuit.

In terms of structure, compared with the passive PFC active PFC circuit, there is a very big difference, that is active PFC circuit saves a large volume of silicon steel sheet inductance, so the weight will be lighter than passive PFC circuit. And as its apparent difference is an inductance coil. Here, however, don't recommend relying on inductance coil to judge whether the power active PFC, because of the large inductance coil within the power supply, no circuit does not distinguish between knowledge. However, due to the active PFC power PFC circuit itself need to consume a certain power, if used in low power (here refers to under 300 w) often than passive PFC power save electricity power supply, therefore is not common in such products. In addition, because the active PFC circuit booster ability, can allow a lower input voltage, so to adapt to the mains in a relatively wide range, up to 110 v - 240 - v.

Of course, is active PFC circuit and the difference between the two passive PFC circuit, there is a way to identify the most obvious, the most effort is that we can use the product shell annotation to identify on the nameplate. In the nameplate products are "Active PFC" or "Active PFC is Active PFC, haven't marked is passive PFC circuit structure.