Double ended converter with output synchronous rectifier and auxiliary input regulator

A system to convert a dc voltage input to an ac approximately sinusoidal current for a dc-to-ac power converter, the system comprising:

• a dc input with a pair of dc input terminals;
• a transformer having a primary winding with a tap and a second, output winding to provide said ac current;
• a pair of switches each coupled to one of said input terminals and to a respective end of said primary winding, said tap being connected to the other of said pair of dc input terminals;
• and
• a controller configured to control each of said pair of switches in turn during respective first and second half cycles of said approximately sinusoidal current using a pulse width modulated control such that each of said switches generates a current to approximate one of said half cycles of said approximate sinusoid;
• said system having an output from said output winding.

A DC-to-AC power converter, the converter including a transformer having a primary and a secondary winding, the primary winding of the transformer being coupled to a dc input of the power converter and the secondary winding of the transformer being coupled to an ac output of the converter, and wherein:

• a first and second switch connected to the primary winding of the transformer to convert a dc supply from the dc input to an ac current for driving the transformer;
• a first and second switch connected to the secondary winding of the transformer such that the first switch is in a forward path to the ac output and the second switch is in a return path to the ac output;
• a first and second diode coupled across the respective first and second switches connected to the secondary winding;
• and wherein
• the first switch connected to the primary winding of the transformer is controlled to provide a first half cycle of an ac voltage to the primary winding of the transformer;
• the second switch connected to the primary winding of the transformer is controlled to provide a second half cycle of an ac voltage to the primary winding of the transformer;
• and
• the first and second switches connected to the secondary winding of the transformer as switched to alternately conduct the first and second half cycles of the signal coupled from the primary winding of the transformer to the secondary winding of the transformer.

A controller for controlling a DC to AC power converter, the power converter comprising a transformer having a primary winding and a secondary winding, a first and second switch connected to the primary winding of the transformer, a first switch connected to the secondary winding of the transformer in the forward path to an ac output and second switch connected to the secondary winding of the transformer in the return path to the ac output, and a first and second diode coupled across the respective first and second switches connected to the secondary winding;

• the controller comprising:
• a plurality of outputs to control each of the first and second switches connected to the primary winding of the transformer and first and second switches connected to the secondary winding of the transformer;
• wherein the controller controls the first and second switches connected to the primary winding of the transformer to convert a dc input to an ac current to drive the primary winding of the transformer;
• the controller controls the first and second switches connected to the secondary winding of the transformer to alternately conduct the first and second half cycles of the signal coupled from the primary winding of the transformer to the secondary winding of the transformer.