Patent ID: 6621238
Filing Date: 2003-09-16
Classification: H02M,H05B,Y02B

Abstract:
A ballast circuit, comprising:a bridge rectifier; a power factor correction circuit operationally coupled to the bridge rectifier, wherein the power factor correction circuit sources a d.c. bus to subsequent ballast circuit components and provides a return line associated with the bus, wherein the power factor correction circuit charges the bus during a startup period with a first pre-determined current defining a startup charging rate and during a steady-state period with a second pre-determined current defining at a steady-state charging rate, wherein the first pre-determined current is higher than the second pre-determined current and the startup charging rate is higher than the steady-state charging rate; a bus capacitor operationally coupled to the d.c. bus and return line of the power factor correction circuit; and at least one inverter operationally coupled to the d.c. bus and return line of the power factor correction circuit.