Device operating in a state connected to an image forming apparatus and controlling a power supply when switching modes

An image forming system comprising:

• an image forming apparatus configured to form an image onto a recording material;
• a device operating in a state connected to the image forming apparatus,
• wherein the image forming apparatus and the device are operable in a first mode in which a predetermined operation is executed and in a second mode of which power consumption is reduced rather than in the first mode,
• wherein the image forming apparatus includes:
• a power source portion configured to generate a Direct Current (DC) voltage from an Alternating Current (AC) voltage supplied from an external power source;
• and
• a fixing portion configured to fix the image onto the recording material and including a first heating portion, and
• wherein the device includes:
• an operating portion configured to operate by the AC voltage supplied from the external power source;
• a first switching portion configured to supply the AC voltage to the operating portion in a conductive state and to cut off supply of the AC voltage to the operating portion in a non-conductive state;
• a control portion configured to operate by the DC voltage generated from the AC voltage by the power source portion;
• and
• a second heating portion configured to heat the recording material,
• wherein the control portion controls to cause the first switching portion to be in the non-conductive state so as to stop operation of the operating portion and supplying the AC voltage into the second heating portion when the image forming apparatus shifts from the first mode to the second mode.