Abstract: A light emitting apparatus includes a light source block with semiconductor light sources connected in series to each other. A resistor is connected in parallel with one or more of the semiconductor light sources and is connected to two detecting target portions in portions linked to respective electrodes of the semiconductor light sources. A ground fault detecting circuit is connected to one of the two detecting target portions disposed on a ground potential side. The light source block has one of its terminals connected to a power supply and its other terminal grounded. By detecting a change in the voltage through the ground fault detecting circuit, a ground fault can be detected.

Abstract: A light emitting apparatus includes a light source block with semiconductor light sources connected in series to each other. A resistor is connected in parallel with one or more of the semiconductor light sources and is connected to two detecting target portions in portions linked to respective electrodes of the semiconductor light sources. A ground fault detecting circuit is connected to one of the two detecting target portions disposed on a ground potential side. The light source block has one of its terminals connected to a power supply and its other terminal grounded. By detecting a change in the voltage through the ground fault detecting circuit, a ground fault can be detected.

Abstract: A vehicular lamp used for a vehicle includes a semiconductor light emitting element for emitting light, a resistor for current detection for causing a current detection voltage in response to a current flowing through the semiconductor light emitting element, the resistor being coupled in series to the semiconductor light emitting element, a serial diode being coupled in series to the resistor for current detection and the semiconductor light emitting element in a forward direction, and an open circuit detecting unit for detecting an open circuit of the semiconductor light emitting element based on a sum voltage, which is a sum of a forward voltage of the serial diode and the current detection voltage.

Abstract: A vehicular lamp used for a vehicle includes a semiconductor light emitting element for emitting light, a resistor for current detection for causing a current detection voltage in response to a current flowing through the semiconductor light emitting element, the resistor being coupled in series to the semiconductor light emitting element, a serial diode being coupled in series to the resistor for current detection and the semiconductor light emitting element in a forward direction, and an open circuit detecting unit for detecting an open circuit of the semiconductor light emitting element based on a sum voltage, which is a sum of a forward voltage of the serial diode and the current detection voltage.