US 12,464,617 B2
Method of selecting PWM dimming frequency for dimmable LED power supply
Guobiao Wen, Meizhou (CN)
Assigned to Zhuhai Shengchang Electronics Co., Ltd., Zhuhai (CN)
Filed by Zhuhai Shengchang Electronics Co., Ltd., Zhuhai (CN)
Filed on Nov. 21, 2023, as Appl. No. 18/515,833.
Claims priority of application No. 202211626532.7 (CN), filed on Dec. 16, 2022.
Prior Publication US 2024/0206032 A1, Jun. 20, 2024
Int. Cl. H05B 45/325 (2020.01); H05B 45/10 (2020.01)
CPC H05B 45/325 (2020.01) [H05B 45/10 (2020.01)] 3 Claims
OG exemplary drawing
 
1. A method of selecting a PWM dimming frequency for a dimmable LED power supply, applied to an LED dimmable power supply, the LED dimmable power supply comprising a power MOS tube and a main power drive, a dimming signal processing circuit, a main control module and four-shift switching module, which are sequentially coupled to one another, the power MOS tube having a gate coupled to the main control module, a source coupled to the main power drive, and a drain coupled to a negative electrode of a lamp, and the main power drive being coupled to a positive electrode of the lamp, characterized in that the method comprises the steps of:
detecting a shift element signal status of the four-shift switching module by the main control module after the main power drive is powered on;
determining a dimming PWM pulse frequency currently outputted by the power supply according to the shift element signal status based on the main control module, and collecting a signal sample of the dimming signal processing circuit to obtain a sample signal; and
determining a PWM drive signal according to the dimming PWM pulse frequency and the sample signal based on the main control module, and controlling a switch status of the power MOS tube according to the PWM drive signal to adjust a lamp brightness.