Abstract: A DC soft turn-off module includes a switch contact and a soft turn-off circuit connected in parallel onto the switch contact. The soft turn-off circuit includes three branches connected each other in parallel. The first branch includes a thermistor and a first thyristor connected in series. The second branch comprises a capacitor and a first resistor connected in series. A second thyristor, a second resistor and a third resistor form a trigger branch for the first thyristor. The third branch includes a varistor connected in parallel onto the first branch and the second branch.

Abstract: The present invention relates to a circuit minimizing standby power in a power adapter with a power-frequency transformer (T1), which includes a sensing circuitry (1), a driving circuitry (2), a switching circuitry (3) and a resistive element (Z). When the sensing circuitry (1) senses a power supply signal of the power-frequency transformer (T1) in work mode, the switching circuitry (3) shorts the resistive element (Z); and when the power-frequency transformer (T1) is in standby mode, the electronic switch (3) is switched off and the resistive element (Z) is coupled to the power-frequency transformer (T1). The circuit attached to the power adapter reduces the standby power consumption very much, and achieves energy-saving effect with low cost.

Abstract: The present invention relates to a circuit minimizing standby power in a power adapter with a power-frequency transformer (T1), which includes a sensing circuitry (1), a driving circuitry (2), a switching circuitry (3) and a resistive element (Z). When the sensing circuitry (1) senses a power supply signal of the power-frequency transformer (T1) in work mode, the switching circuitry (3) shorts the resistive element (Z); and when the power-frequency transformer (T1) is in standby mode, the electronic switch (3) is switched off and the resistive element (Z) is coupled to the power-frequency transformer (T1). The circuit attached to the power adapter reduces the standby power consumption very much, and achieves energy-saving effect with low cost.