Patent ID: 7378806
Filing Date: 2008-05-27
Classification: H05B,Y02B

Abstract:
1. A continuous mode electronic ballast for operating a lamp comprising: a buck converter configured to generate a direct current (DC) bus voltage at buck converter output; an inverter circuit operationally coupled to the buck converter output, configured to receive the generated DC voltage and convert the DC voltage into an AC voltage to drive the lamp; a short circuit protection circuit which is operationally coupled to the buck converter output to sense the DC bus voltage, compare the sensed DC bus voltage to a predetermined threshold and, based on the comparison, shut down the inverter circuit; a power line resistor which is operationally coupled to the buck converter output and which receives the DC bus voltage; a storage capacitor operationally coupled to the power line resistor and inverter circuit, which storage capacitor accumulates a charge through the power line resistor and supplies power to the inverter circuit after initial ignition of the lamp; and a latch, operationally connected to the storage capacitor, which latch is in an “ON” state when the sensed voltage is less than the predetermined threshold, and which discharges the storage capacitor and shuts down the inverter circuit.