Patent ID: 11956870
Assignee: NICHIA CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. A light source device to supply a constant current to a diode load, the diode load comprising a plurality of light-emitting elements connected in series, the light source device comprising:
a power supply circuit configured to be connected to the diode load; and
a peak current limiting circuit configured to be connected in series to the diode load,
wherein the peak current limiting circuit comprises
a current detector connected in series to the diode load, and
a current-regulating circuit configured to control a current to the diode load by a detection voltage of the current detector,

wherein the current detector comprises a series circuit comprising a resistor and a coil,
wherein the current-regulating circuit comprises:
a transistor having an input side and configured to be connected in series to the diode load and the current detector;
a comparator having a first input terminal and a second input terminal, and connected to the input side of the transistor; and
a reference voltage circuit to input a reference voltage to the first input terminal of the comparator,

wherein a detection voltage induced in the current detector is input to the second input terminal of the comparator,
wherein an output of the comparator is input to the transistor, and
wherein the transistor is configured to control a current to the diode load.