US 12,244,221 B2
Method and circuit arrangement for controlling a switched-mode power supply
Bernhard Peeck, Wiedensahl (DE)
Assigned to Wago Verwaltungsgesellschaft MBH, Minden (DE)
Filed by WAGO Verwaltungsgesellschaft mbH, Minden (DE)
Filed on Oct. 7, 2022, as Appl. No. 17/962,226.
Claims priority of application No. 10 2021 126 399.9 (DE), filed on Oct. 12, 2021.
Prior Publication US 2023/0114055 A1, Apr. 13, 2023
Int. Cl. H02M 1/32 (2007.01); H02M 1/00 (2006.01)
CPC H02M 1/32 (2013.01) [H02M 1/0003 (2021.05); H02M 1/0025 (2021.05)] 14 Claims
OG exemplary drawing
 
1. A method for controlling a switched-mode power supply comprising a current limiting control to limit an output current of the switched-mode power supply to a predetermined maximum limiting current value and comprising a current boost control for setting the predetermined maximum limiting current value to a predetermined overcurrent value, which is higher than a predetermined maximum current value for a predetermined boost time, the method comprising:
passing the output current through a measuring resistor;
comparing a measuring voltage dropping across the measuring resistor with a first comparison voltage as a measured value proportional to the output current;
setting the first comparison voltage to a nominal comparison voltage correlating with the predetermined maximum current value or to a boost comparison voltage higher than the nominal comparison voltage and correlating with the predetermined overcurrent value;
using the comparison result as a control signal for limiting the output current to either the predetermined maximum current value or the predetermined overcurrent value;
applying a constant reference voltage to a voltage divider which is formed by a series connection of voltage divider resistors;
tapping the first comparison voltage across a first part of the voltage divider resistors as a component of the constant reference voltage dropping across the first part of the voltage divider resistors; and
bypassing at least one of the voltage divider resistors to set the first comparison voltage to the nominal comparison voltage for limiting the output current of the switched-mode power supply to the predetermined maximum current value.