| 摘要 |
PURPOSE:To reduce the size and the cost of a lighting circuit by installing an auxiliary anode in an electric discharge tube, and locating a main electric-discharge path almost parallel to one another. CONSTITUTION:When a transistor 4 conducts, current flows through a power source 1, a parallel circuit consisting of an inductance 2 and a capacitor 8, and a transistor 4 in that order. At this point, since voltage applied to an electric discharge tube 3 has a polarity reverse to that of the electric discharge tube 3, electric discharge doesn't develop. When a transistor 4 is cut off, reverse power develops in the inductance 2, and voltage determined by the condenser 8 and the inductance 2 develops in the inductance 2. The polarity of this voltage is the forward direction of the electric discharge tube 3. If a cathode 31 is heated by a cathode-heating winding, electric discharge is inititated from an auxiliary anode 33 in which high voltage develops, then shifts to the electric discharge of a main anode 32. Here, electric discharge doesn't develop between the auxiliary anode 33 and the main anode 32. This is because both of these members have anodic structures and hardly discharge electrons. |
