Power supply apparatus and image forming apparatus including the same

An image forming apparatus comprising:

• a power supply apparatus configured to switch between a normal operation mode in which power is supplied to a plurality of loads including a first load and a power saving mode in which power is supplied to a part of the loads including at least the first load, to supply power to the loads;
• an image forming portion, provided as one of the loads other than the first load, configured to perform image formation on a recording medium;
• and
• an input reception portion, provided as the first load, configured to receive input of a signal representing a print instruction issued to the image forming portion, wherein
• the power supply apparatus includes:
• a first power supply configured to supply power to the plurality of loads;
• a second power supply having an output current capacity which is less than that of the first power supply;
• a current detection portion configured to detect current consumption of the first load that is operating;
• a determination portion configured to determine whether or not the current consumption detected by the current detection portion is less than or equal to the output current capacity of the second power supply;
• and
• a supply control portion configured to supply, based on a result of determination made by the determination portion, power to the first load from one of the first power supply and the second power supply in the power saving mode.