INDIRECTLY CONNECTED SWITCHING APPARATUS WITH SPARE BATTERY

摘要

An off-line switcher includes an auxiliary winding (22) on the secondary side of the power transformer (20) coupled by a power switch (14) to a secondary voltage source (12) in order to provide uninterruptible power to the output (10) from either a primary AC (1) or the secondary DC source. The power switches (13, 14) coupling both primary and secondary source voltages to the power transformers are driven at identical duty cycles by a common regulation control (30). Differing transformation ratios between primary and secondary sources of power define different operational ranges and determine flow of power based on the magnitude of the primary source of power.