Patent ID: 7116084

Claim:
A step-up converter having power factor correction, having an input for connection to a supply voltage (U C1 ); an inductor (L) having a freewheeling time (dt a ), a diode (D) and a storage capacitor (C 2 ) coupled in a series arrangement between the input and an output, in which a voltage (U C2 ) dropped across the storage capacitor (C 2 ) is provided at the output; a switch (S) coupled between a junction point between the inductor (L) and the diode (D), and a reference potential; and a drive circuit ( 10 ) for the switch (S) which controls times (dt e ; dt a ) for which the switch (S) remains closed and open; characterized, in that the drive circuit ( 10 ) controls a time (dt e ) for which the switch (S) remains closed as a function of the freewheeling time (dt a ) of the inductor (L).