US 12,352,823 B2
Method and circuit for monitoring power supply
Yuan-Kai Cheng, Jhubei (TW); and Chun-Chiang Chen, Jhubei (TW)
Assigned to Infsitronix Technology Corporation, Jhubei (TW)
Filed by INFSITRONIX TECHNOLOGY CORPORATION, Jhubei (TW)
Filed on Sep. 23, 2022, as Appl. No. 17/951,597.
Claims priority of provisional application 63/247,487, filed on Sep. 23, 2021.
Prior Publication US 2023/0168312 A1, Jun. 1, 2023
Int. Cl. G01R 31/40 (2020.01); G01K 7/22 (2006.01); G01R 15/04 (2006.01); G01R 19/165 (2006.01); H02H 3/20 (2006.01); H02H 5/04 (2006.01); H02M 3/335 (2006.01)
CPC G01R 31/40 (2013.01) [G01K 7/22 (2013.01); G01R 15/04 (2013.01); G01R 19/16538 (2013.01); G01R 19/1659 (2013.01); H02H 3/20 (2013.01); H02H 5/04 (2013.01); H02M 3/33592 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for monitoring power supply, comprising:
sensing a winding voltage of a switching power supply using an auxiliary winding for acquiring an auxiliary side voltage;
acquiring a divided voltage of said auxiliary side voltage using a voltage division circuit, said voltage division circuit including a first impedance element and a second impedance element, and said second impedance element including a thermistor,
using a first detection circuit to detect said divided voltage and generate a first detection signal in a switching period of said switching power supply; and
using a second detection circuit coupled between said first impedance element and said second impedance element to form a detection current flowing to said second detection circuit and generating a second detection signal in said switching period;
wherein said first detection circuit and said second detection circuit operate respectively when the secondary winding of said switching power supply is discharging in said switching period and said first detection signal and said second detection signal correspond to an ambient temperature and an output voltage of said switching power supply respectively.