Switching power supply and constant-current linear changing method for current, and control circuit of LED lamp

Abstract

The invention discloses a switching power supply and a constant-current linear changing method for a current, and a control circuit of an LED lamp. The switching power supply comprises a power supply, a current-limiting module and a pulse control module, wherein the power supply is coupled with the input end of the pulse control module, the power supply voltage end of the current-limiting module and an external load separately; the signal input end of the current-limiting module is coupled with the pulse signal output end of the pulse control module; the load signal input end of the current-limiting module is coupled with the external load; and the pulse control module is used for generating a pulse signal, and inputting the pulse signal into the current-limiting module. The current-limiting module is used for controlling the time interval of switching-on time and switching-off time of the load signal input end of the current-limiting module to enable the current input to the external load to be linearly changed in a constant-current manner. By controlling the current input to the external load to be linearly changed in a constant-current manner, the stability of the current input to the lamp is further improved; and the luminance stability of the lamp manufactured by taking an LED as a light emitting material can be further improved.

Description

technical field [0001] The invention relates to the field of electrical technology, in particular to a switching power supply, a constant current linear change method, and a control circuit for an LED lamp. Background technique [0002] With the development and improvement of science and technology, lamps made of light-emitting diodes (Light Emitting Diode, LED) as light-emitting materials have been widely used. Most of the light-emitting tubes of lamps are composed of several LEDs connected in series or in parallel. In the lamp, the brightness of the lamp can be controlled by controlling the magnitude of the current passed into the light-emitting tube. However, in the current prior art, the control circuit in the lamp cannot well control the current passing into the luminescent tube. It cannot be well adapted to the required adaptation of the light-emitting tube in low light, resulting in the instability of the light emission of the lamp in low light, and also the unstabl...

AI Technical Summary

Problems solved by technology

However, in the current prior art, the control circuit in the lamp cannot well control the current passing into the luminescent tube. It cannot be well adapted to the low light conditions of the light-emitting tubes, resulting in the instability of the light emission of the lamps in low light conditions, and also the unstable brightness in low light conditions.

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