Abstract: A power amplifier for receiving an input signal and providing a corresponding amplified output signal. One embodiment of the power amplifier includes a positive half circuit for supplying power to an amplifier during positive half waves of the output signal and a negative half circuit for supplying power to the amplifier during negative half waves of the output signal. Each half circuit has a main power supply, which is typically a switching regulator, and which supplies a first power signal to the amplifier. The slew rate of this first power signal is intentionally limited to control EMI emissions. Each half circuit also has a transient power supply which may be selectively engaged to provide a second power signal to the amplifier when the first power signal is insufficient to power the amplifier.

Abstract: A power tooth brush, including a barrel or casing with an electric motor therein. A rotating brush member has a shank fitted in the front end of the barrel with a brush element exposed to the exterior. Sleeve means drivingly interconnects the shank of the brush member and the drive shaft of the motor. The sleeve is of compound construction, including a fixed element and a movable element, with cam means interacting between the elements producing axial vibration of the brush member in response to its rotation. In one form, a battery is included for running the motor, so that the device is self-contained and in this form it is adapted for having a cap fitted thereon, whereby it is easily carried in the pocket and easily used in travel. Another form is adapted to plug-in operation.

Abstract: A cigarette case having a closure member movable to selective positions for exposing or releasing a single or individual cigarette. The closure member and body of the case have detents indicating the position of the closure member to expose the desired cigarette, or be at a desired position, for exposing or releasing the next cigarette. The case includes means forming cells for the individual cigarettes.