Auxiliary power supply for AC powered electronics

摘要

Techniques for supplying auxiliary power to AC powered lighting devices are disclosed. An auxiliary power supply can be used, for example, to provide auxiliary power to lighting control circuitry, an LED driver, or any other electronic lighting device. In some example embodiments, the linear regulator is connected to a switch that is controlled by a control circuit such that the linear regulator operates only when the instantaneous line input voltage is in a certain range where the linear regulator has a somewhat good efficiency. In such cases, when the linear regulator is operating, energy is stored with an auxiliary capacitor connected to the output of the linear regulator. In some embodiments, the linear regulator is configured to operate only when the line voltage is between a determined upper and lower voltage threshold; while in other cases the linear regulator is configured to operate only when the line voltage is increasing through the predetermined voltage threshold values.

主权项

1. An auxiliary power supply circuit, comprising:
a linear regulator configured to directly receive a line voltage from an AC voltage source; a switch connected to the linear regulator, wherein the linear regulator only operates when the switch is active; and a control circuit configured to close the switch based on the instantaneous value of the line voltage.