Abstract: An AC-DC converter includes a DC reference voltage generation unit that creates a DC reference voltage waveform based in part on a feedback signal. The AC-DC converter also includes an SCR firing unit that receives a variable frequency power output from the generator and that provides firing signals. The AC-DC converter further includes SCRs arranged as a positive bank of SCRs and a negative bank of SCRs. The AC-DC converter further includes a modulator unit that receives the firing signals and the DC reference voltage waveform, and that respectively outputs SCR gate signals to the SCRs. The AC-DC converter also includes a filter unit provided between the positive and negative banks of SCRs. The AC-DC converter also includes a voltage feedback path for feeding back the DC output voltage as the feedback voltage waveform.

Abstract: An aerospace power control system switches an aerospace load from a faulty ac power bus to a good ac power bus of two or more ac power buses if the currently connected ac power bus is about to fail. The voltage level and frequency of the power provided on the buses are monitored to determine which of the power buses are within required limits to provide power to the aerospace load. If monitoring of the currently connected ac power bus indicates that the bus is not within the required limits and may be shut down in the immediate future, the connection of the aerospace load is switched to another ac power bus which is within the required limits. The current provided to the load is monitored to determine zero-crossing points of the current with the switch from the currently connected faulty bus to a good bus being performed at a zero-crossing point of the load current. The level of the current being provided to the aerospace load is also monitored to detect a faulty load condition.