A three-way dimming ballast circuit for driving a ballast power switching circuit powering a gas discharge lamp such as a CFL. An elongate slot is defined in a center of each pressing member. , a digital still camera, has a coprocessor connected to a CPU; the coprocessor has register groups which are electrically connected one another, each register group having registers of 32 bits length; and the registers store a one-byte image data in the zero-th to third bytes, respectively. The first driver includes a first capacitor having a first terminal electrically connected to a control electrode of the first power switch and a second terminal electrically connected to the first output terminal. Each inner plate and each outer plate of opposing walls can be components of the same housing shell.