Method and apparatus for rapid, synchronized, and isolated transistor switching

Abstract

A switching circuit has switching devices, detector and driver circuits, and a transformer. Each detector and driver circuit detects when a control and driving signal present on the transformer secondary is in an “on” or “off” state and, responsive thereto, drives the switching device on or off, respectively, by applying to it the control and driving signal. A control and driving signal includes a voltage waveform across a secondary winding. The detector and driver circuit has on-threshold and off-threshold detectors that respectively detect that the control and driving signal is in “on” or “off” states when its voltage reaches on-threshold or off-threshold voltages. Driver circuits drive the switching devices on or off responsive to the on-threshold or off-threshold detectors, respectively. A controller applies to a primary driven winding a first set of voltages, thereby generating (i) a first current in the primary driven winding, (ii) a first magnetic field having a first quantum of energy, and (iii) a magnetically induced second set of voltages in the secondary winding. The controller interrupts the first current, thereby causing the first magnetic field to collapse, and, not later than interrupting the first current, clamps the primary driven winding to a third set of voltages, thereby magnetically inducing a fourth set of voltages in the secondary winding. At least one of the fourth set of voltages is less than at least one of the second set of voltages. The control and driving signal includes the second and fourth sets of voltages.

Dependencies are inferred from the claim text.