Improvements avoiding GHz-glitch caused by igniters for Xenon HID-lamps
Publication Date: 2004-Sep-03
The IP.com Prior Art Database
ID298886 and ID298887
A typical set-up for driving Xenon HID (High Intensity Discharge) lamps, e.g. for automotive applications, consists of a driver, an igniter and the Xenon HID lamp. The three components are typically arranged as described in figure 1:
Figure 1: System set-up driving a Xenon HID-lamp
Improved systems integrate the igniter into the base of the Xenon HID lamp. The integrated igniter is connected to the driver by use of a three wired shielded cable, called harness. The shielding of the harness allows a continuous shielding of the system, because the driver and the igniter are also capsulated by an electric conductive shielding. The shielding of the igniter is typically isolated to the electronics inside the igniter.
One possible concept for the igniter is to use a serial high voltage (HV-) generator. The HV-generator might be realized by an HV-transformer. One disadvantage of the concept is, that high frequency (HF-) transients occurring immediately after the ignition of the bulb might inject into the harness to the driver and in case of high HF-glitches the driver might even be destroyed.
The amplitude of the glitch depends strongly on the level of the ignition voltage and of the duration of the ignition process of the Xenon HID lamp. The shape of the glitch is also determined by the resulting parasitic capacities and inductivities of the electrical circuit in the igniter.
Following concepts can be used to l...