A variable speed wind turbine is disclosed comprising a turbine rotor that drives a doubly-fed induction generator, a matrix converter which converts variable frequency output into constant frequency output, and a control unit and a protection circuit for the matrix converter. A roaming terminal device requesting to use a gateway is detected. One of the first coil and the second coil is fitted into the space between coil turns of the other, insulated from the coil turns of the other by a second insulating film, and the first and second coils are connected to each other so as to generate magnetic flux in the same direction. An error detection module generates an error signal based on digitized values of the input signal and a target value. With the inclusion of the louvered opening, enhanced combustion is assured and any potential crazing zone of the oven cavity is shifted to a position wherein, should any heat resistant material chip off due to heat from the igniter, the material will be blocked from falling into any food support zone of the oven cavity. As an example, an array of memory cells may include a group of memory cells each having a resistive storage element coupled to a select device.