Patent ID: 7773391

Claim:
A direct current (DC) to DC converter comprising: a first DC input configured to be connected to a first DC power supply; a second DC input configured to be connected to a second DC power supply; a transformer comprising a primary winding, a sub-primary winding, and a secondary winding for outputting an alternating current (AC) voltage; a pulse reverse circuit comprising an input configured for receiving a square pulse, and an output configured for providing a reverse square pulse; a first switch transistor comprising a source electrode connected to ground, a drain electrode connected to the first DC input via the primary winding of the transformer, and a gate electrode for receiving the square pulse; and a second switch transistor comprising a source electrode connected to ground, a drain electrode connected to ground via the sub-primary and a capacitor in series, and a gate electrode connected to the output of the pulse reverse circuit; wherein the pulse reverse circuit comprises a third transistor, a fourth transistor, a bias resistor and a diode, a collector electrode of the third transistor being connected to the second DC input, an emitter electrode of the third transistor being connected to the gate electrode of the second switch transistor, a base electrode of the third transistor being connected to a collector electrode of the fourth transistor, the collector electrode of the fourth transistor being connected to the second DC input via the bias resistor, an emitter electrode of the fourth transistor being configured to be connected to ground, and a base electrode of the fourth transistor configured for receiving the square pulse, a positive electrode of the diode connected to the emitter electrode of the third transistor, and a negative electrode of the diode connected to the collector electrode of the fourth transistor.