Abstract: An ignitor disabler for the starter circuit of a High Intensity Discharge (HID) lamp includes means for disabling the ignitor, and means for triggering the disabling means of the ignitor after passage of a predetermined amount of time. The triggering means has a timing component that begins time measuring operation only under certain, predetermined conditions. The disabler includes means for resetting the timing component of the triggering means upon lamp ignition. In its preferred embodiment, the starter circuit specifically includes a power supply portion in use to convert alternating current to direct current and designed to provide a stable direct current output over a broad range of input signals.

Abstract: An ignitor disabler for the starter circuit of a High Intensity Discharge (HID) lamp includes means for disabling the ignitor, and means for triggering the disabling means of the ignitor after passage of a predetermined amount of time. The triggering means has a timing component that begins time measuring operation only under certain, predetermined conditions. The disabler includes means for resetting the timing component of the triggering means upon lamp ignition. In its preferred embodiment, the starter circuit specifically includes AC threshold voltage establishing means and a field effect transistor for ensuring that a timing capacitor in the disabler triggering circuit is effectively discharged to zero volts. The disabler trigger circuit may operate down to minus 40.degree. C.

Abstract: An ignitor disabler for disabling an ignitor in a high intensity discharge lamp monitors the operating or characteristic voltage of the lamp. When the characteristic voltage of the lamp exceeds an AC threshold established by the disabler, the ignitor disabler disables the ignitor to prevent spurious pulses. In this manner, the ignitor is effectively disabled during periods when the lamp is operating abnormally. The ignitor disabler includes a timing network which is reset only when an excessive voltage is detected. The reset portion of the disabler includes a field effect transistor for discharging the timing network.