Disclosed is a control circuit of an electronic ballast for a fluorescent lamp, wherein the control circuit comprises a protection circuit and an automatic re-lamp circuit. The acoustic apparatus includes a first receiver, a second receiver, a resonator, and a transmitter. A valve body is associated with the nuclear fission fuel element, and the valve body defines a plenum therein for receiving the gaseous fission product. Then, the output ports of the driving units, which approach the same input voltage, are electrically connected to have an average voltage. A heel is movably mounted to the top block half.