Power supply apparatus for outputting first and second voltages from one transformer and image forming apparatus including power supply apparatus

An image forming apparatus comprising:

• an image bearing body having a surface on which a toner image is formed;
• first and second process members acting on the image bearing body;
• and
• a power supply apparatus configured to output a voltage to the first and second process members,
• the power supply apparatus including
• a one transformer having a primary coil and a secondary coil, and
• a first rectifier smoothing unit configured to rectify and smooth an alternating-current voltage generated in the secondary coil of the transformer, a first voltage output from the first rectifier smoothing unit being supplied to the first process member,
• a separation unit configured to receive the alternating-current voltage generated in the secondary coil of the transformer as an input and generate an alternating-current voltage, from which alternating-current components are separated, as an output,
• a second rectifier smoothing unit configured to rectify and smooth the output of the separation unit, a second voltage having a polarity opposite to a polarity of the first voltage and output from the second rectifier smoothing unit being supplied to the second process member,
• a resistor connected to a line branched from a line that connects the separation unit to the second rectifier smoothing unit, and
• a rectifier unit connected in series between the resistor and a reference potential.