T5 LAMP END OF LIFE PROTECTION CIRCUIT

摘要

Provided are an end-of-life protection circuit for a non-isolated electronic ballast and a method for protecting same. The non-isolated electronic ballast includes a driver circuit (104), a sampling circuit (108), and a control circuit (102). The driver circuit (104) connects to an output circuit (106) for controlling operation of a load. The sampling circuit (108) samples direct current (DC) voltage values of a capacitor of a lamp coupled to the ballast to detect occurrence of an asymmetric event. The control circuit (102) receives a voltage value in response to detecting the asymmetric event and outputs to the driver circuit (104) a control signal to control operation of the driver circuit (104) to prevent end-of-life damage. Provided also are an end-of-life protection circuit for an isolated electronic ballast and a method for protecting same.

主权项

1. An end-of-life protection circuit for a non-isolated electronic ballast, comprising:
a driver circuit connected to an output circuit for controlling operation of a load; a sampling circuit configured to sample direct current (DC) voltage values of a capacitor of a lamp coupled to the ballast to detect the occurrence of an asymmetric event; and a control circuit for receiving a voltage value in response to the detection of the asymmetric event from the sampling circuit and for outputting to the driver circuit a control signal to control operation of the driver to prevent end of life damage.