USB Phone World Posting Page
Thursday, September 15, 2011
Do you know how to figure out the performance of your laptop charger? Actually, the specifications of AC adapter in reality have really got great significance to laptop users. There’s a part inside the charger that can show the utilization ratio of electric energy, PFC, power factor correction.
As to most of laptops, this PFC is very helpful for us to judge if certain consumer electronic is wasting the power energy. When the power factor comes to be higher, it means the electronic product will be also very high in energy utilization ratio.
According to industrial rule, all the laptop chargers in the market need to pass the industrial certification and installed PFC circuit. The location of this equipment is between the second filtering and full bridge rectifier.
There’re two types of PFC, one with power resource and another is active. The passive PFC has adopted inductance compensation ways to improve the output power factor in both voltage and current. Usually, the utilization ratio is about 0.7 to 0.8. The advantage is its simple circuit, low cost and little electromagnetic interference.
Active PFC is composed by LC and electron components. Thanks to the small size, it is able to adjust current waveform by appropriative IC that can also compensate the phase difference between current and voltage. Compared to the passive version, this active PFC can reach more than 98% in power factor, but the production cost is relatively higher. In addition, it can also be regarded as auxiliary power supply. In the process of use, we usually don’t need standby transformers. The advantage is the wide voltage accommodation and high power factor.
If you are about to get a laptop charger replacement, please take the PFC type and performance into granted. If you need to work under high pressure, active version is more reasonable. However, as to most of terminal users, passive version is of the highest cost performance.
To be simply, whether you need a passive or active PFC, we need to consider of our actual work and potential requirement. Of course, if your laptop computer is of high configuration or updated system with additional functions, the active PFC is necessary.
by: USB Phone World