Patent ID: 7874891

Claim:
A yo-yo comprising: first and second side portions secured together in a spaced-apart relation by an axle structure; a tether operatively connected to said axle structure; wherein said first side portion comprises a body member, a plurality of permanent magnets fixedly secured to said body member in a manner wherein said permanent magnets are spaced apart from each other, and a board member; wherein said board member is rotatably secured to said yo-yo in a manner whereby said board member is freely rotatable relative to said body member, wherein a sensor capable of detecting a magnetic field is secured to said board member and said permanent magnets are positioned to be capable of passing adjacent said sensor, wherein an electromagnet is secured to said board member, wherein a control unit is secured to said board member and is operatively connected to said sensor and said electromagnet, and wherein an electrical power source is operatively connected to said control unit, said sensor and said electromagnet; and wherein when electrical power is being supplied to said sensor and there is relative movement between said body member and said board member in a manner whereby said body member has a rotational momentum, whenever a first one of said permanent magnets passes by said sensor, said sensor will send a signal to said control unit whereby said control unit will then cause said electromagnet to become temporarily energized whereby said electromagnet will apply a force to another of said permanent magnets in a manner whereby said force tries to at least maintain said rotational momentum of said body member.