| 摘要 |
PURPOSE:To reduce the size and cost of a device, to simplify the circuit, to decrease the generation of noise, and to prevent the generation of switching losses. CONSTITUTION:Harmonic components generated by an electric-discharge-lamp lighting circuit 12 are suppressed by a first capacitor C11, a second capacitor C12, and a diode D11, and the generation of noises is reduced. Only when a charging capacitor 13 is being charged, a transistor Q11 connected in parallel reversely to the diode D11 is turned on and current flows in the reverse blocking direction of the diode D11 too. In correspondence with the voltage value of a pulsating voltage, the first and second capacitors C11 and C12 are connected in parallel, and prevent oscillation generated by a primary winding Tr 11a and the second capacitor C12. A triangular wave and voltage is prevented from piling up and increasing, and bad influence on to a transistor Q12, etc., is prevented. |
