Method for reducing standby energy consumption of switching power supply

Abstract

The invention discloses a method for reducing standby energy consumption of a switching power supply, and particularly relates to the technical field of switching power supplies. The method comprises the following step in which, the switching power supply is arranged into two sets, including a main power supply and an auxiliary power supply, the main power supply and the auxiliary power supply can be simultaneously turned on and off, or one of the main and auxiliary power supplies is turned on and the other is turned off, when the switching power supply is started, an auxiliary winding supplies power to a control chip of the switching power supply, and at the time of starting, the voltage of a starting resistor in the switching power supply drops, and then a set of capacitors are connected in series in the circuit with the starting resistor being turned on. The method of the invention regulates the two sets of power supplies, extracts ripple phase signals in the output of the power supplies, and adjusts the phase difference of the two sets of power supplies to keep the phase difference of the two sets of power supplies 180 degrees all the time, so that the two sets of power supplies are superimposed to make the output voltage ripple greatly reduced. In this way, the problem of increased output voltage ripple due to clock frequency reduction is eliminated, the standby loss of the switching power supply is reduced, and the standby efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of switching power supplies, and more specifically, the invention relates to a method for reducing standby energy consumption of switching power supplies. Background technique [0002] With the increasing importance of energy efficiency and environmental protection, people have higher and higher expectations for the standby efficiency of switching power supplies. Customers require power supply manufacturers to provide power products that can meet green energy standards such as BLUE ANGEL, ENERGY STAR, and ENERGY 2000. The requirements for power supply are: by 2005, for switching power supplies with rated power of 0.3W~15W, 15W~50W and 50W~75W, the standby power consumption should be less than 0.3W, 0.5W and 0.75W respectively. At present, when most switching power supplies are transferred from rated load to light load and standby state, the power supply efficiency drops sharply, and the standby efficiency ca...

AI Technical Summary

Problems solved by technology

[0004] However, while improving the standby efficiency in practical applications, it also brings some problems. The output cannot be effectively adjusted within the load range, the response speed is slow, and the decrease in the clock frequency will lead to an increase in the output voltage ripple, which will affect the performance of the switching power supply.