US 12,261,523 B2
Switching power supply
Masao Noro, Hamamatsu (JP); and Yoshiro Miyake, Hamamatsu (JP)
Assigned to Yamaha Corporation, Hamamatsu (JP)
Filed by Yamaha Corporation, Hamamatsu (JP)
Filed on Mar. 1, 2023, as Appl. No. 18/116,021.
Application 18/116,021 is a continuation of application No. PCT/JP2021/031760, filed on Aug. 30, 2021.
Claims priority of application No. 2020-147424 (JP), filed on Sep. 2, 2020.
Prior Publication US 2023/0208311 A1, Jun. 29, 2023
Int. Cl. H02M 1/42 (2007.01); H02M 1/00 (2007.01); H02M 3/335 (2006.01)
CPC H02M 1/4258 (2013.01) [H02M 1/0025 (2021.05); H02M 1/0022 (2021.05); H02M 3/33507 (2013.01); H02M 3/33569 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A switching power supply comprising:
a rectifying circuit configured to rectify an AC voltage that has been input and configured to output the rectified voltage as a first voltage;
a switching circuit configured to switch the first voltage based on a feedback signal into a switching voltage;
an output circuit configured to generate a second voltage based on the switching voltage; and
a feedback circuit configured to generate the feedback signal based on the first voltage and the second voltage, the feedback circuit comprising:
a carrier wave generation circuit configured to generate a carrier wave having a predetermined period and a wave height variable based on an average of the first voltage, the carrier wave having a non-linear shape at least at one of a rising edge and a falling edge of the carrier wave;
a PWM circuit configured to generate a PWM signal based on a comparison between the first voltage and a voltage of the carrier wave, the PWM signal having a wave height corresponding to the second voltage, wherein due to the non-linear shape of the carrier wave, as the first voltage is higher, a pulse width of the PWM signal is changeable more greatly based on a change in the first voltage; and
a low-pass filter configured to generate the feedback signal based on the PWM signal.