Abstract: A drive circuit for a power device includes a power transistor utilized to drive the power device. The drive circuit utilizes a resonant circuit that drives the power transistor at a high current level when the gate of the power transistor is in its Miller region. In one embodiment, the drive circuit includes dual transistors and an inductor tuned to the gate capacitance to drive the gate of the power transistor. The drive circuit may be useful in a variety of areas, such as with a valve controller for a camless engine.

Abstract: A variable compression ratio engine includes a support shaft positioned eccentrically relative to rotating shafts. A restricting projection is provided at one location in the circumferential direction on the rotating shafts so as to project outward in the radial direction. A rocker member has a pair of engagement portions with respective phases displaced from each other and which engage the restricting projection. The rocker member is spring-biased in a direction in which one of the two engagement portions engages the restricting projection and is mounted on a shaft member so as to be able to rock around the axis of the shaft member. An actuator is driven by the engine negative pressure and is connected to the rocker member so as to swing the rocker member in a direction opposite to the spring-bias direction.