Patent ID: 9160241
Filing Date: 2015-10-13
Classification: H02M,H05B

Abstract:
1. A driver circuit for driving a load circuit, the driver circuit comprising a transformer circuit with a primary side winding to be coupled to a source circuit and with a secondary side winding to be coupled to the load circuit, and a determination circuit for determining a secondary side current as a function of a primary side current and a primary side voltage and a primary side inductance and a transformer ratio, wherein the load circuit comprises a load, the load comprising one or more light emitting diodes, said function defining the secondary side current to be proportional to a difference between a first signal proportional to an integral of the primary side voltage divided by the primary side inductance and a second signal proportional to the primary side current, wherein the difference is multiplied by the transformer ratio, and wherein the primary side inductance is an inductance measured at a primary side of the transformer circuit for an open secondary side of the transformer circuit, the transformer ratio being a voltage ratio of the transformer circuit for an open secondary side of the transformer circuit, and the difference is rectified before or after being multiplied by the transformer ratio and the difference is low-pass filtered after being multiplied by the transformer ratio.