| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device, an LED device, and a light source device which can enhance the safety of maintenance work while suppressing power consumption.SOLUTION: An input voltage determination circuit 30 is provided with a diode 31 provided at the output side of a voltage conversion section 12 and a parallel circuit with a resistance 33 and a capacitor 32 connected to a cathode of the diode 31, and determines the presence or absence of an input voltage according to the presence or absence of a voltage of the capacitor 32. A switch circuit 40 is provided with a first transistor 41 connected in series with the resistance 20 as the discharge resistance, a second transistor 42 for controlling the conduction and non-conduction of the first transistor 41 according to the determination by the input voltage determination circuit 30, and a series circuit with the resistance 43 for applying a bias voltage to the first transistor 41, and a Zener diode 44. |
