Patent ID: 8493101

Claim:
A drive circuit with a transmission circuit for transmitting a signal from a primary side having a first ground to at least one secondary side, each at least one secondary side having a second ground, the drive circuit comprising: a transformer having capacitive coupling between the primary side and the at least one secondary side, said transformer having two branches, an ON transmission branch and an OFF transmission branch, each of said branches having a first partial branch and a second partial branch, each of said partial branches including a high voltage capacitor, each of said second partial branches including an inverter; a secondary side ON transmission branch capacitor coupled in series with said high voltage capacitor in said first partial branch of said ON transmission branch; a secondary side OFF transmission branch capacitor coupled in series with said high voltage capacitor in said first partial branch of said OFF transmission branch; said ON transmission branch including means for receiving an input signal and applying the input signal to said first partial branch of said ON transmission branch and to said inverter within said second partial branch thereof; and said OFF transmission branch including an inverter for receiving the input signal and applying it to said inverter within said second partial branch thereof and also applying it, inverted, to said OFF transmission branch; wherein said capacitive coupling between the primary and secondary sides is effected in each partial branch by means of said capacitors; and wherein each said partial branch has, on the primary side, a bridge circuit comprising an n-channel transistor and a p-channel transistor with a center point therebetween, said center point being connected to one of said high-voltage capacitors which is in turn connected, on the secondary side, to a respective associated node which is connected to a respective one of said secondary-side capacitors and a comparator, and has an associated partial connection to a respective voltage divider.