待机功耗问题

电能---->热能
摸摸哪些器件发热就知道了.

我说的是在NO LOAD的情况下,很难有较热的元件.

待机损耗主要来源于
1)FET等开关损耗
2)变压器损耗
3)RCD损耗
4)启动电路损耗
5)预负荷损耗(包括IC等)
主要解决方式:
1)降频
2)降反压
3)间歇式工作
4)用专用IC
按以上方式,即便用普通IC(像UC3842等),200W以内的电源,待机损耗可以降到1W以下.

疑问:3842光启动电阻就耗电不少,如何做到1瓦以下?

各位仁兄,有做十几瓦开关电源吗?介绍一款给你,肯定超值!有兴趣和我联系.

CoolSET™ F2  
  Second Generation Integrated Power ICs with Enhanced Protection Features and Low Standby    

Features:  
Lowest standby power consumption <300mW @ no load condition
Lowest on-resistance for record efficiency levels
650V or 800V avalanche rugged CoolMOS Power MOSFET is integrated optionally
100kHz or 67kHz fixed switching frequency
Overload
Open loop
Overvoltage
Soft start
Thermal shut down
All integrated protection features are with automatic re-start
Improved modulated gate drive for lower EMI
Input voltages AC 85V...270V