Simplifying the composition of the automotive HID lamp electronic ballast has been considered. This paper describes the novel electronic ballast that is composed of a DC/DC converter, a capacitor connected to a lamp in series, a switch (S₃) connected to the capacitor in parallel, a switch (S₂) placed between the output terminals of the DC/DC converter and also connected in parallel to the lamp and the capacitor in series, and an igniter. All MOSFETs (S₁ in the DC/DC converter, S₂ and S₃) in the ballast are operated on the common voltage position (GND) of the circuit. The DC/DC converter is operated intermittently and the operation of S₂ synchronizes with the operation of it to supply the lamp with an alternate square wave voltage. Operating an automotive HID lamp succeeded using the novel ballast and by setting some issues below.
1) The occurrence of the power loss when S₂ is turned on.
2) The occurrence of extinction of gas discharge.
This paper describes how the loss can be decreased if a part of the energy stored in the output capacitor of the DC/DC conveter is used to operate the lamp before S₂ is turned on. It also describes how an inductor and a capacitor were added to the proposed electronic ballast to raise the lamp voltage in order to prevent the current from disappearing.