Patent ID: 7233135
Filing Date: 2007-06-19
Classification: H02M

Abstract:
1. A ripple converter comprising: a switching element arranged to switch an input direct-current voltage; a choke coil and a smoothing capacitor arranged to smooth the switched direct-current voltage; a flywheel device arranged to cause a current to flow through the choke coil when the switching element is turned off; and a control circuit arranged to perform feedback control as to whether the switching element is on or off according to ripple in an output voltage; wherein the control circuit includes a waveform converter arranged to convert a waveform of a signal that is proportional to the output voltage and output a resulting signal, and a comparing unit arranged to compare the output of the waveform converter with a reference voltage and output a result of the comparison; said waveform converter includes a plurality of resistors and at least one capacitor; the at least one capacitor and at least one of the plurality of resistors of the waveform converter are connected in series, and another of the plurality of resistors is connected in parallel to the at least one capacitor and the at least one of the plurality of resistors; and one end of each of the at least one of the plurality of resistors and the another of the plurality of resistors is directly connected to a non-inverting input terminal of the comparing unit.