| 摘要 |
<p>An inverter circuit (40) for an uninterruptible A.C. power supply includes a high frequency (50 KHz.) pulse width modulator (100) receiving a reference waveform (102) and sensed waveform (106) derived from the inverter output. The modulated high frequency pulses are applied to a pair of gating means (152) operable during respective phases of the A.C. signal and having outputs connected via drivers (168) controlled by a POWER FAIL signal to apply the high frequency signals to pairs of MOSFET switches (176a-d) coupled to respective primary windings of a pair of transformers (186, 192). The transformer secondaries are coupled via further MOSFET switches (210, 232) operable during respective phases of the A.C. signal and a pair of chokes (200, 214) to the load (34). Fast inverter operation in response to a power fail condition is achieved.</p> |
