US 5,295,036 A · Lighting circuit for vehicular discharge lamp

Abstract

A lighting circuit for a vehicular discharge lamp having a DC voltage booster circuit for boosting an input voltage from a DC voltage input terminal, comprises a current detector, a voltage detector, an abnormality judging circuit, and a power cutoff relay circuit. The current detector acquires a detection signal concerning an output current of the DC voltage booster circuit. The voltage detector acquires a detection signal concerning an output voltage of the DC voltage booster circuit. The abnormality judging circuit compares the levels of the detection signals from the current detector and the voltage detector with each other to determine whether or not the lighting circuit is in an abnormal status. The power cutoff circuit inhibits power supply to the discharge lamp upon reception of a signal from the abnormality judging circuit representing an abnormality in the lighting circuit.

Claims18

Dependent claims

A lighting circuit for a vehicular discharge lamp having a DC voltage booster circuit for boosting an input voltage from a DC voltage input terminal, comprising:

a current detector for acquiring a detection signal directly representative of an output current of the DC voltage booster circuit;
a voltage detector for acquiring a detection signal directly representative of an output voltage of the DC voltage booster circuit;
an abnormality judging circuit for comparing levels of the detection signals from the current detector and the voltage detector with each other to determine whether or not the lighting circuit is in an abnormal status;
and
a power cutoff circuit for inhibiting power supply to the discharge lamp upon reception of a signal from the abnormality judging circuit representing an abnormality in the lighting circuit.

2 more elements

A lighting circuit for a vehicular discharge lamp having a DC voltage booster circuit for boosting an input voltage from a DC voltage input terminal, comprising:

a detector for acquiring a detecting signal directly representative of an output current or output voltage of the DC voltage booster circuit;
an abnormality judging circuit for detecting the output voltage or output current of the DC voltage booster circuit, acquiring a reference value directly representative of a corresponding output current or output voltage of the DC voltage booster circuit, and comparing the reference value with the level of the detection signal from the detector with each other to determine whether or not the lighting circuit is in an abnormal status;
and
a power cutoff circuit for inhibiting supply of a DC voltage to the DC voltage booster circuit upon reception of a signal from the abnormality judging circuit representing an abnormality in the lighting circuit.

1 more element

Dependencies are inferred from the claim text.

Lighting circuit for vehicular discharge lamp

Life of this patent

Lighting circuit for vehicular discharge lamp

Life of this patent

Abstract

Claims18