POWER SUPPLY DEVICE AND LED LIGHTING DEVICE

Provided is a power supply device, which, even if an excess in output occurs on an LED lighting device side, is capable of preventing a drop in the voltage supplied to another machine that is connected aside from the LED lighting devices, and continues driving the other machine. This power supply device is equipped with a plurality of LED drive circuits provided in parallel, corresponding respectively to a plurality of LED lighting instruments, and are constituted in such a manner as to drive each of the LED lighting instruments in a predetermined light-emission mode. The plurality of LED drive circuits, along with the other machine aside from the plurality of LED drive circuits, are connected to a DC supply unit having such constitution that a direct current power supply voltage is converted into a predetermined direct current voltage and supplied thereby. The power supply device is further provided with a constant current circuit whereof the input side is connected to the DC supply unit and the other machine, and the output side is connected to the plurality of LED drive circuits.