Light emitting apparatus with current limiting

A light emitting apparatus comprising:

• a DC/DC converter to chop, in response to a chopping signal that controls an on/off operation, and transform an output of a DC power supply, convert a voltage obtained by the transformation into a DC power and supply the DC power to a load,
• a plurality of semiconductor light sources as the load of the DC/DC converter in an output loop of the DC/DC converter,
• a current limiting circuit to limit a current of the semiconductor light sources and to inhibit flow of an overshoot current to the semiconductor light sources,
• wherein the current limiting circuit comprises a resistor connected in series with the plurality of semiconductor light sources, a voltage across the resistor corresponds to the current of the semiconductor light source, and the DC/DC converter is connected to the resistor to receive the voltage across the resistor as a feedback signal, and
• a switching device group comprising a plurality of switching devices to short-circuit or open both ends of at least one of the semiconductor light sources in response to switching signals, wherein the amount of light of the semiconductor light source is defined with an OFF duty of the switching signals.

A light emitting apparatus comprising:

• a DC/DC converter to chop, in response to a chopping signal that controls an on/off operation, and transform an output of a DC power supply, convert a voltage obtained by the transformation into a DC power and supply the DC power to a load,
• a plurality of semiconductor light sources as the load of the DC/DC converter in an output loop of the DC/DC converter,
• a current limiting circuit to compare a signal corresponding to a first switching signal with a signal corresponding to a current flowing to the semiconductor light sources, to open/close the output loop in accordance with a result of the comparison, and to cause a current to flow to the semiconductor light sources so as not to exceed a maximum current while the output loop is closed,
• wherein the current limiting circuit comprises a resistor connected in series with the plurality of semiconductor light sources to detect the current flowing to the semiconductor light sources, the signal corresponding to a current flowing to the semiconductor light sources comprises a voltage across the resistor, and the DC/DC converter is connected to the resistor to receive the voltage across the resistor as a feedback signal, and
• a switching device group to short-circuit or open both ends of at least one of the semiconductor light sources in response to second switching signals,
• wherein the amount of light of the semiconductor light sources is defined with an ON duty of the first switching signal and an OFF duty of the second switching signal.