A new control method using JFET for an off-line flyback converter with low stand-by power consumption

Zero No-Load Power AC/DC Adapter for Electronic Equipment With Embedded Battery

“…To meet the standby power regulation, many standby power reduction techniques have been proposed in [6]- [15]. Among several techniques, the burst-mode control [6] and the highvoltage (HV) start-up circuit [8] are commonly employed in the commercial control IC.…”

“…Moreover, the CAPZero is adopted to reduce the power consumption at discharging resistor R dis for electromagnetic interference (EMI) filter [9]. A no-load power consumption of the conventional ac/dc adapter with these techniques is over several hundred milliwatts [10]- [15]. Although the conventional ac/dc adapter with these techniques meets the no-load requirement [4], [5] with margin, some countries are gradually tightening no-load requirement and some computer manufactures are asking for more stringent no-load requirement, even as low as 30 mW.…”