LED color temperature adjusting device and method based on single-channel PWM (pulse width modulation)

Abstract

The invention discloses an LED color temperature adjusting device and method based on single-channel PWM (pulse width modulation). The LED color temperature adjusting device comprises a microprocessor, a warm color temperature switch control circuit, a cold color temperature switch control circuit, a warm color temperature LED lamp and a cold color temperature LED lamp. The method includes: respectively inputting preset-frequency PWM signals to the warm color temperature switch control circuit and the cold color temperature switch control circuit; according to the input PWM signals, controlling brightness of the warm color temperature LED lamp and the cold color temperature LED lamp which are connected with the warm color temperature switch control circuit and the cold color temperature switch control circuit respectively by the same. The LED color temperature adjusting device is simple in structure, the method is simpler and more reliable in realization, resource using efficiency can be improved effectively, and changing amplitude of brightness of the LED lamps can be uniform, so that brightness can be maintained unchanged when color temperature is adjusted; adjusted color temperature can change continuously, so that color temperature adjusting range is effectively expanded, and actual using effect of LED color temperature changing is improved. The LED color temperature adjusting device and method can be widely applied in the field of LEDs.

Description

technical field [0001] The invention relates to the technical field of LEDs, in particular to a single-channel PWM-based LED color temperature adjustment device and a method thereof. Background technique [0002] At present, the technology of adjusting the color temperature of LEDs mainly uses two channels of PWM to control the two LEDs separately. By increasing the duty cycle of one PWM and reducing the duty cycle of the other PWM, the color temperature can be adjusted. [0003] However, when the color temperature is adjusted by dual-channel PWM, when the duty cycle of the PWM is controlled by software, the color adjustment method of the two-channel PWM cannot realize all the values ​​in the theory, but can only realize some specific areas, so the adjusted color temperature cannot be Continuous change, the LED brightness will also change when the color temperature is adjusted. SUMMARY OF THE INVENTION [0004] In order to solve the above technical problems, the purpose o...

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Problems solved by technology

[0003] However, when the color temperature is adjusted by dual-channel PWM, when the duty cycle of the PWM is controlled by software, the two-channel PWM color adjustment method cannot achieve all the values ​​in theory, but can only achieve some specific areas, so the adjusted color temperature cannot Continuous change, the LED brightness will also change when the color temperature is adjusted

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