Switching power supply, control method for switching power supply, and control chip

Abstract

The invention proposes a switching power supply, a control method for the switching power supply, and a control chip. The switching power supply includes a light modulator, an input filtering rectifying module and the control chip. The control chip includes a light-modulator switching module, a control module and a primary constant-current circuit. The control module includes a light-modulator control circuit and a primary-constant-current control circuit. The switching power supply is capable of detecting the work mode of the light modulator and outputting corresponding control signals so that when the switching power supply is constructed, light modulators of a plurality of kinds of work modes can be selected and power supply construction is convenient. The on-off of the primary constant-current circuit is automatically adjusted with the size of output current so that the output current is controlled at a constant value. At the same time, the on-off time of the light modulator is controlled through the control chip and compared with a scheme in which the on-off time of a light modulator is controlled through a peripheral circuit, the light modulator only needs a simple switching module and thus cost reduction is facilitated.

Description

technical field [0001] The invention relates to the technical field of electronic information, in particular to a switching power supply, a control method of the switching power supply and a control chip. Background technique [0002] At present, with the enhancement of human awareness of environmental protection and energy saving, a new generation of semiconductor lighting sources will definitely subvert the current status of general lighting applications and become the mainstream of lighting in the future with its advantages of high efficiency, low consumption, energy saving, environmental protection, fast response, and long life; At the same time, under the impetus of the "Energy Star" (Energy Star) program of the US National Environmental Protection Agency and the Chinese Bid Certification Center (CECP), new energy efficiency standards for power supplies are being announced around the world. (PFC) or mandatory standard requirements to reduce harmonic currents has become ...

AI Technical Summary

Problems solved by technology

Obviously, in order to ensure the normal operation of the thyristor dimmer, this traditional thyristor dimming solution requires a lot of components, which will lead to a higher cost of the whole solution, and is not conducive to the operation of application design and other aspects

Images