Patent ID: 8519683
Filing Date: 2013-08-27
Classification: H02M

Abstract:
1. A DC-DC converter comprising: a main switch connected to two ends of a DC power supply via a first primary winding and a second primary winding of a transformer, the second primary winding connected to the first primary winding in series; a first series circuit connected to two ends of the main switch, and including a hoist winding, a first reactor, a first diode and a smoothing capacitor, the hoist winding connected to the second primary winding in series; a second series circuit connected to the two ends of the main switch, and including a second diode, a third diode and the smoothing capacitor; a soft-switching circuit configured to cause the main switch to perform a soft-switching operation each time the main switch turns off; a control circuit configured to turn on and off the main switch; and a switching control circuit configured to switch the soft-switching circuit between an operating mode and a non-operating mode in accordance with a state of a load; wherein the soft-switching circuit includes a third series circuit including a fourth diode, an auxiliary switch, a second reactor and a capacitor, the third series circuit including one end connected to a connection point between the first primary winding and a second primary winding of the transformer, and another end connected to a negative electrode of the DC power supply, and a connection point between the second reactor and the capacitor is connected to a connection point between the second diode and the third diode.