Patent ID: 7837570

Claim:
A swing device comprising a support frame, a seat having a swing axis and swing back and forth about the swing axis while a bar thereof being hung on the support frame, and a repulsive circuit for repelling a permanent magnet installed on the swing axis, wherein the repulsive circuit includes: a coil assembly instantly generating induced current when the permanent magnet passes by with a certain distance therebetween, and being supplied with power to become an electromagnet having the same polarity as the permanent magnet to instantly repel the permanent magnet; a first switching element for switching the induced current generated in the coil assembly; a second switching element switched on by the induced current switched from the first switching element to turn off the switching operation of the first switching element and to control a power switching operation at the same time; and a power switching unit for temporarily switching the power to the coil assembly according to the control of the power switching operation of the second switching element.