Abstract: A method and apparatus, known as an inverter, for converting a source of DC power such as that from batteries, to an alternating voltage similar to what is available from a standard domestic wall plug, but with substantially less power wasted in the inverter itself at low loads, than prior art inverters. At low loads, the inverter produces an output voltage waveform whose average value, as measured by the magnitude of the integral of each half-cycle of the output voltage waveform, is less than the average value of a half-cycle of a sinusoidal voltage waveform having the same period and same extreme voltages as the output voltage waveform.

Abstract: A toothbrush which includes a toothbrush body (12) and a lever arm (14) having toothbrush bristles (18) at one end thereof. The lever arm (14) is mounted for pivotal movement at a pivot member (16) which is in the vicinity of the other end of the lever arm (14). In one embodiment, a pair of permanent magnets (44, 46) are provided at the other end of the lever arm (14), positioned side-by-side with opposite polarities. An electromagnet (24) is provided to the rear of the lever arm (14). The electromagnet (24) includes an E-core having top, bottom and center legs (30, 31, 33) with a coil (36) wound around its center leg (33) which receives an alternating current driving signal from an oscillator/battery section (38). The frequency of operation is in the range of 150-400 Hz. The action of the alternating current in the electromagnet (24) causes the lever arm (14) to move about the pivot member (16), first in one direction and then in an opposing direction to provide the desired vibrating effect.

Abstract: A vibrating toothbrush which includes a toothbrush body (12) and a lever arm (14) having toothbrush bristles (18) at one end thereof. The lever arm (14) is mounted for pivotal movement at a pivot member (16) which is in the vicinity of the other end of the lever arm (14). In one embodiment, a pair of permanent magnets (44, 46) are provided at the other end of the lever arm (14), positioned side-by-side with opposite polarities. An electromagnet (24) is provided to the rear of the lever arm (14). The elecromagnet (24) includes an E-core having top, bottom and center legs (30, 31, 33) with a coil (36) wound around its center leg (33) which receives an alternating current driving signal from an oscillator/battery section (38). The frequency of operation is in the range of 150-400 Hz. The action of the alternating current in the electromagnet (24) causes the lever arm (14) to move about the pivot member (16), first in one direction and then in an opposing direction to provide the desired vibrating effect.