Delta 750W SMPS

http://www.hkepc.com/?id=1404&fs=c1hp


They wrote:

此外，為保護部件免於在啟動電腦時因巨大的瞬間電流造成破壞， Delta 研發部門特地在輸入部份設置一組型號為松川 201-1AH 的繼電器 (Relay) ，將啓動時的瞬間電流引渡至另一組線路上以作保護，當輸入穩定以後，繼電器將關閉保護電路以減低無謂的電能損耗。使用額外線路上以作保護，在不需要時自動將其關閉，這種設計概可提升產品的使用壽命，亦可同時減低效能的犧牲，無疑是聰明的方法，值得讚賞。


To Alvis Tang(Writer), please read the following comment from me.

1. The PWM controller have softstart function.
2. The inrush current should not enough to kill the rectifier.
3. Simple question, when AC is ZERO, relay OFF, AC is ON, what function will be first on ? Relay should not be that function.

The SMPS have 2 parts. Main and Standby PWM controller.
To enter a Green mode, say 0.1W - 1W standby power, most engineer will found a method to fully switch off the main PWM controller include the PFC controller to archieve the lower standby power.

But actually, the PFC + PWM + Standby controller should exceed 1W in standby power at total value.

How will they do? Simple adding a MOSFET or Relay to swich off the PFC, PWM parts.  

Then they will pass the Green mode test....

PS: The PWM controller is ST UC3842, it should not a green mode PWM controller....

KK.Ho