A dimming method with frequency change of dimming signal

Abstract

The present invention provides a dimming method for changing the frequency of the dimming signal. The method generates a continuous pulse signal, and the pulse signal is output to the lamp to realize the purpose of dimming. It is characterized in that the pulse signal consists of several periods TA The pulse generated in and the pulses generated in several cycles TB, the method includes the following steps: step 1, parameter initialization; step 2, timer interrupt; step 3, enter cycle TA or cycle TB according to cycle mark S to generate Pulse signal; step 4A, output pulse according to the mapping table; step 5A, calculate pulse width W; step 4B, start outputting pulse at a predetermined position; step 5B, calculate pulse width W; step 6, judge whether to end a single cycle; step 7 , reset the parameters and loop back to step 2.

Description

technical field [0001] The invention relates to a dimming method, in particular to a dimming method in which the frequency of a dimming signal changes. Background technique [0002] The common way to adjust the brightness of existing LED lamps is to use PWM dimming technology. This technology is based on the premise that the frequency of the output dimming signal remains unchanged, and the duty cycle is adjusted by changing the width of the signal pulse to achieve The dimming effect of LED lamps, and in large-scale LED projects, when installing a large number of LED lamps, the pulse of the above-mentioned dimming signal frequency may cause interference to other lamps in the project, and in serious cases may cause the entire LED project to be abnormal, increasing the LED The construction difficulty of the project, in the prior art, the way to solve the interference is to add a large number of signal isolators, but this will increase the equipment cost and labor cost in the pr...

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Problems solved by technology

[0002] The common way to adjust the brightness of existing LED lamps is to use PWM dimming technology. This technology is based on the premise that the frequency of the output dimming signal remains unchanged, and the duty cycle is adjusted by changing the width of the signal pulse to achieve The dimming effect of LED lamps, and in large-scale LED projects, when installing a large number of LED lamps, the pulse of the above-mentioned dimming signal frequency may cause interference to other lamps in the project, and in serious cases may cause the entire LED project to be abnormal, increasing the LED The construction difficulty of the project. In the existing technology, the solution to the interference is to add a large number of signal isolators, but this will increase the equipment cost and labor cost in the project. Therefore, it is necessary to propose an improvement

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