AUXILIARY RECHARGE
A charging circuit supplies charge to a charge store to provide power to a controller of a power converter. The power converter includes an inductive component having a winding coupled to receive power from an input to the power converter. A switching circuit includes a field effect transistor (FET) and a switching element. The FET is coupled in series between the winding and the switching element. A controller is coupled to control the switching of the switching element, and a charge store is coupled to provide power to the controller. The charging circuit includes a current diversion circuit coupled to conduct a winding current from the FET to the charge store. The switching element is arranged to allow the winding current to flow through the current diversion circuit to the charge store.
1 . A charging circuit for supplying charge to a charge store for providing power to a controller of a power converter, the power converter comprising:
an inductive component having a winding coupled to receive power from an input to the power converter;
a switching circuit comprising a field effect transistor (FET) and a switching element, the FET coupled in series between the winding and the switching element;
a controller coupled to control the switching of the switching element; and
a charge store coupled to provide power to the controller;
the charging circuit comprising:
a current diversion circuit coupled to conduct a winding current from the FET to the charge store; and
the switching element arranged to allow the winding current to flow through the current diversion circuit to the charge store.
2 . The charging circuit of claim 1 , wherein the switching element is a decoupling element.
3 . The charging circuit of claim 2 , wherein, the decoupling element is coupled to receive a winding current wherein the winding current is a current derived from the winding.
4 . The charging circuit of claim 1 , wherein the controller is a switching controller.
5 . The charging circuit of claim 1 , wherein the decoupling element is arranged to decouple a control line of the FET.
6 . The charging circuit of claim 1 , wherein the FET conducts the winding current to the current diversion circuit.
7 . The charging circuit of claim 1 , wherein the current diversion circuit comprises a diode configured to conduct the diverted winding current when forward-biased.
8 . A charging circuit for supplying charge to a charge store for providing power to a controller of a power converter, the power converter comprising:
an inductive component having a winding coupled to receive power from an input to the power converter;
a switching circuit comprising a field effect transistor (FET) and a switching element, the FET coupled in series between the winding and the switching element;
a controller coupled to control the switching of the switching element; and
a charge store coupled to provide power to the controller, the charging circuit comprising:
means for conducting current from the winding through the FET; and
means for diverting the current through a conduction path to the charge store.
9 . The charging circuit of claim 8 , wherein the switching element is a decoupling element.
10 . The charging circuit of claim 9 , wherein the decoupling element is a transistor.