Driver for switching device

Abstract

A driver for a switching device has a plurality of driver circuits for driving the switching device and a control circuit. The control circuit selectively operates the driver circuits in response to a plurality of predetermined drive modes. Alternatively, a driver for a switching device has a driver circuit and a control circuit. The driver circuit is connected to a plurality of power sources. Each of the power sources has a different voltage. The control circuit selects one of the power sources for operating the driver circuit in response to a plurality of predetermined drive modes.

1 . A driver for a switching device, comprising: 
 a driver circuit connected to a plurality of power sources, each of the power sources having a different voltage; and    a control circuit operative to select one of the power sources for operating the driver circuit in response to a plurality of predetermined drive modes.    
   
   
       2 . The driver according to  claim 1 , wherein the driver circuit includes a push-pull circuit, an electrical resistance and a power source select circuit, the power sources being connected to a top and bottom ends of the push-pull circuit through the power source select circuits, one terminal of the electrical resistance being connected to a control terminal of the switching device, the other terminal of the electrical resistance being connected to an output terminal of the push-pull circuit.  
   
   
       3 . The driver according to  claim 1 , wherein the driver circuit includes an electrical resistance and the same number of push-pull circuits as the power sources, each of the power sources being connected to a top and bottom ends of each push-pull circuit, one terminal of the electrical resistance being connected to a control terminal of the switching device, the other terminal of the electrical resistance being connected to an output terminal of the push-pull circuit.  
   
   
       4 . The driver according to  claim 3 , wherein each of the push-pull circuits that is not connected to the power source having a highest voltage in the plural power sources connect diodes at the top and bottom ends of the push-pull circuit.  
   
   
       5 . The driver according to  claim 1 , wherein the switching device is selectively driven in a plurality of control frequencies, the drive modes being selected in response to the selected control frequency.  
   
   
       6 . The driver according to  claim 5 , wherein the switching device is a component of an H bridge circuit, the drive modes including a normal drive mode and a current limit mode.  
   
   
       7 . The driver according to  claim 6 , wherein the normal drive mode is operated in a commercial alternating-current frequency, the current limit mode being operated in a frequency that is at least one hundred times as high as the commercial alternating-current frequency.  
   
   
       8 . The driver according to  claim 6 , wherein the switching device is configured for a ground side in the H bridge circuit.