| 摘要 |
<p>An uninterruptible power supply is disclosed having an inverter that operates on either high voltage d.c. supplied by a line-powered power supply or on low voltage d.c. batteries. With line power, the inverter operates as an ?bridge inverter. With battery power, the battery voltage is applied to a smaller portion of the inverter's transformer primary. The changeover from line to battery power is determined by when an intermediate voltage tapped from the transformer drops below the battery voltage.</p> |
